## 1. The Argument for Anomalous Monism



The basic structure of the argument for Anomalous Monism is as
follows. We start with the plausible assumption that some mental
events, such as believing that it is raining, are caused by certain
physical events, in this case the rain. Similarly, it is assumed that
some physical events, such as one's arm rising, are caused by
certain mental events, such as deciding to scratch one's head.
Davidson calls this the Principle of Causal Interaction; we shall call
it the interaction principle:



> 
> 
> *The Interaction Principle*: Some mental events causally
> interact with some physical events
> 
> 
> 



Davidson presents this assumption as obvious and not in need of
justification, but we shall see that motivations for it can be found
in parts of his writings
 (2.2).
 To this interaction principle is added the requirement that all
singular causal interactions are covered by strict laws--laws
with fully articulated antecedents which guarantee some fully
articulated consequence (for caveats and details,
 see 3.1).
 Davidson calls this the Principle of the Nomological Character of
Causality; we shall call it the cause-law principle:



> 
> 
> *The Cause-Law Principle*: Events related as cause and effect
> are covered by strict laws
> 
> 
> 



This cause-law principle was also initially assumed without argument
by Davidson, though we shall see below
 (3.2)
 how he later came to try to justify it. Now, the assumptions so far
seem to point directly to the existence of strict psychophysical
laws--if some particular mental event *m*1 is
caused by some particular physical event *p*1, then,
given the cause-law principle, it seems to follow that there must be a
strict law of the form
'*P*1 - *M*1'.
That is, whenever events of kind *P*1 occur, events
of kind *M*1 must follow. However, Davidson then
claims that there can be no such laws. He calls this the Principle of
the Anomalism of the Mental, and it holds that mental properties are
not suitable for inclusion in strict laws of any kind; we shall call
it the anomalism principle:



> 
> 
> *The Anomalism Principle*: There are no strict laws on the
> basis of which mental events can predict, explain, or be predicted or
> explained by other events
> 
> 
> 



Davidson offered loose ruminations concerning rationality and
rationalizing explanations, which purportedly constitute the very
nature of mental properties, in support of the anomalism principle
 (4.2).
 All of this will be discussed in detail below.



With the interaction principle, the cause-law principle, and the
anomalism principle now in place, we can see that there is a tension
in need of resolution. From the interaction and cause-law principles
it follows that there must be strict laws covering the interaction
between mental and physical events. But the anomalism principle
entails that there are no strict psychophysical laws. How can all
three principles be held simultaneously?



To resolve the tension, Davidson noted that while the cause-law
principle requires that there be strict covering laws, it
doesn't specify the vocabulary in which those laws must be
formulated. If particular physical event *p*1 causes
particular mental event *m*1, and there must be some
strict law covering this interaction, but there is no strict law of
the form
'*P*1 - *M*1',
then there must be some other law,
'?1 - ?2', which
covers the causal relation between *p*1 and
*m*1. That is, *m*1 and
*p*1 must instantiate properties suitable for
inclusion in strict laws; but since we know that
*M*1 is not a property of this kind,
*m*1 must instantiate some other property.
Davidson's ingenious deduction at this point was that this
property must be physical, since only the physical sciences hold out
the promise of a closed system of strict laws (Davidson 1970,
223-24; on the notion of a closed system, see
 5.1
 and the supplement on
 Causal Closure of the Physical in the Argument for Monism).
 Therefore, every causally interacting mental event must be
token-identical to some physical event--hence, monism
 (5.1):



> 
> 
> *Monism*: Every causally interacting mental event is
> token-identical to some physical event
> 
> 
> 



In arguing in this way, Davidson relies upon a key distinction between
explanation and causation. While explanation is, intuitively, an
intensional notion--one sensitive to how events are
described--causation is extensional, obtaining between pairs of
events independently of how they are described. For example, a
bridge's collapse is explained by the explosion of a bomb. That
explosion, let us suppose, was the most newsworthy event of the day.
While the most newsworthy event of the day *caused* the
bridge's collapse, 'the most newsworthy event of the
day' does not *explain* that collapse. Telling someone
that it was the most newsworthy event of the day that explained the
bridge's collapse wouldn't provide an explanation--it
wouldn't make the bridge's collapse intelligible to the
audience--though it would pick out its actual cause. How the
cause is described is relevant to whether an explanation occurs.
Causes and effects can be accurately picked out using a variety of
expressions, many of which are not explanatory. As we shall see, the
distinction between causation and explanation is crucial to Anomalous
Monism
 (6.1-6.3; 
see also related discussion of the intensionality
of *deterministic* relations in 
 Related Issues: 3.1 Anomalous Monism and Kant's Theory of Freedom).




Finally, to alleviate certain concerns about the adequacy of the form
of physicalism he was endorsing, Davidson endorsed a dependency
relation of supervenience of the mental on the physical, and claimed
that it was consistent with Anomalous Monism
 (5.1,
 5.3) (Davidson 1970, 214; 1993; 1995a, 266):



> 
> 
> *Supervenience of the Mental on the Physical*: if two events
> share all of their physical properties, they will share all of their
> mental properties
> 
> 
> 



In what follows (2-5), each step of this argument will be
analyzed and discussed separately, but always with an eye to the
overall argument. In 6, a central objection to Anomalous
Monism--that it appears unable to account for the
causal/explanatory power of mental events and properties--will be
explained and discussed. (For discussion of the relationship between
Anomalous Monism and two other pillars of Davidson's
philosophy--his rejection of conceptual relativism and commitment
to semantic externalism--see the supplement on
 Related Issues.)


## 2. Premise I: The Interaction Principle



The interaction principle states that some mental events causally
interact with some physical events. In this section we will look
briefly at a number of issues related to this principle: how mental
and physical events are demarcated, the nature of events themselves,
the scope of the interaction principle, the relationship between
mental events and causation, and the use of the interaction principle
in establishing one component of mental
anomalism--*psychological anomalism*, according to which
there can be no strict, purely psychological laws. Psychological
anomalism is to be distinguished from *psychophysical
anomalism*, which holds that there can be no strict psychophysical
laws. This latter thesis will be explored in detail in our discussion
of the anomalism principle
 (4).


### 2.1 Mental and Physical Events



Davidson restricts the class of mental events with which Anomalous
Monism is concerned to that of the propositional
attitudes--states and events with psychological verbs such as
'believes', 'desires', 'intends'
and others that subtend 'that-' clauses, which relate
subjects to propositional contents such as 'it is raining
outside'. Anomalous Monism thus does not address the status of
mental events such as pains, tickles and the
like--'conscious' or sentient mental events. It is
concerned exclusively with sapient mental events--thoughts with
propositional content that appear to lack any distinctive
'feel'.



Though traditional and intuitive, this way of dividing up the domain
of the mental isn't without controversy. Generally, Davidson
expresses some skepticism about the possibility of formulating a clear
and general definition of the class of mental phenomena (Davidson
1970, 211). And he is suspicious about the idea of mental states given
to, but uninterpreted by, concepts (Davidson 1974a), which is how
philosophers have often thought of conscious phenomena. But for
current purposes the class of propositional attitudes will suffice as
a criterion for the mental. One key reason for so limiting the reach
of Anomalous Monism, as we shall see
 (4.2),
 is that it is the *rational* status of the relevant mental
events that Davidson usually cites as responsible for mental
anomalism. Conscious events have traditionally been thought to occur
in non-rational animals, a position with which Davidson shows some
sympathy (Davidson 1985a). Such events thus appear to fall outside of
the domain of the rational, and thus outside of the purview of
Davidson's argument.



Davidson is even less helpful about offering a criterion for the
'physical' (Davidson 1970, 211). One half-hearted attempt
comes in the statement that



> 
> 
> [p]hysical theory promises to provide a comprehensive closed system
> guaranteed to yield a standardized, unique description of every
> physical event couched in a vocabulary amenable to law. (Davidson
> 1970, 224) 
> 
> 
> 



This is at best a promissory note about some future language of
'physics'--the 'true' physics--and
it incorporates a requirement of the causal closure of the physical
domain that creates problems for certain aspects of Anomalous Monism
(see the supplement on
 Causal Closure of the Physical in the Argument for Anomalous Monism).
 It is probably best to take a 'physical' description
simply to be one that occurs in the language of a future science that
is similar to what we call 'physics' today but with none
of its inadequacies. One important component of such descriptions is
their capacity to figure in strict laws of nature (see
 3.1).
 While this is non-negotiable for physical terms, it is an open
question for mental terms, and Davidson will be arguing
 (4)
 for a negative answer.



When Davidson first argued for Anomalous Monism he subscribed to a
causal criterion of event-individuation, according to which two events
(event-descriptions) are identical (co-refer) if they share all the
same causes and effects (Davidson 1969). He much later came to reject
that criterion in favor of one according to which events are identical
if and only if they occupy the same spatiotemporal region (Davidson
1985b). The difference between these views will not, however, be
reflected in our discussion. It does not appear to affect either the
derivation or the essential nature of Anomalous Monism. For our
purposes, Davidson's central claims are that what makes an event
mental (or physical) is that it has a mental (or physical)
description, and the extensionalist thesis that events are concrete
entities that can be described in many different ways ('the
flipping of the light switch', 'the illuminating of the
room' and 'the alerting of the burglar that someone is
home' can all pick out the same one event in different terms).
(For controversies concerning extensionalism, see
 5.2
 and the supplement on
 Related Issues
 (Anomalous Monism and Scheme-Content Dualism).)



The interaction principle states that at least some mental events
cause and are caused by physical events (Davidson 1970, 208). This
leaves open the possibility of mental events that do not causally
interact with physical events. However, given Davidson's early
views about event-individuation (the causal criterion) it is unclear
that this possibility can be realized. His later views on
event-individuation appear to leave this possibility open, but his
general claims about the causal individuation of mental contents and
attitudes (see
 4.3
 and
 6.3
 below) also stand in some tension with this possibility. In any case,
Davidson goes on to say that he in fact believes that all mental
events causally interact with physical events (Davidson 1970, 208),
but he restricts his argument only to those that actually do. Given
the pressures just noted in favor of the inclusive reading of the
interaction principle, we shall assume it in what follows.



The interaction claim itself should be understood as follows: some
events that have a mental description or instantiate a mental property
cause and are caused by events that have a physical description or
instantiate a physical property. Formulating the interaction principle
in this way both clears the way for an extensional reading of the
causal relation (events are causally related no matter how they are
described), and also leaves open the possibility, which Davidson will
subsequently argue for, that mental events in particular must have
some non-mental description/instantiate some non-mental property. At
this stage that possibility is left as an open question, but it is
important to notice that for it to be an open question we need to at
least allow for a distinction between events and the ways in which
they are picked out in language.


### 2.2 Mental Causation



Though this will be focused on separately below
 (6),
 it is also important to recognize that we are beginning with the
assumption that mental events cause and are caused by physical events.
Many critics of Anomalous Monism have claimed that it is difficult to
see how the position avoids epiphenomenalism--the view that
mental events are causally/explanatorily impotent--and that
Anomalous Monism is therefore unacceptable as an account of the place
of the mental in the physical world. However, since Anomalous Monism
is *based upon* the interaction principle, Davidson can claim
in response that if Anomalous Monism is true, then mental events are
already known to have a kind of causal efficacy. As we shall see, this
point is not by itself sufficient to ward off all epiphenomenalist
concerns about Anomalous Monism. But it does serve to remind us of the
full framework within which challenges to Anomalous Monism must be
assessed, and in particular brings out the reliance of that framework
on specific assumptions about causality (see Sections
 4.3,
 6, and Yalowitz 1998a).



What needs to be noted at this point is that Davidson argued early on
for the claim that mental events have causal efficacy, through noting
a problem for non-causal accounts of action explanation (Davidson
1963). Mental events and states explain action by making it
intelligible--rational--in light of the agent's
beliefs and purposes. The challenge that Davidson raised for
non-causal theories of action explanation was to account for the fact
that, for any action performed, there may well be a large number of
mental events and states true of the agent, and capable of
rationalizing the action, but that don't thereby
*explain* that action. The agent acted *because* of some
specific beliefs and purposes, but other beliefs and purposes of his
could just as easily rationalize that action, and thus be cited in its
explanation. Was the agent moving his hand as he did because he wanted
to swat the fly, relieve a cramp, or wave in greeting? He may well
have wanted to achieve all three of these aims, but still only in fact
performed the action *because* of one of these reasons. How do
we understand 'because' so as to rule out the pretenders?
Davidson's claim was that it is only if we understand
'because' as 'was caused by' that we can
justifiably pick out the genuine *explanans*--thereby
imputing causal potency to mental events.



What exactly does this argument show? It is intended to tell against
non-causal theories of action, which deny that reasons explain actions
by causing them. There have been sophisticated attempts, on the behalf
of non-causal theories of action explanation, to respond to this
challenge (von Wright 1971; Wilson 1985; Ginet 1995; for a good
overview, see Stoutland 1976; and see related discussion in
 6.3.)
 However, assuming the argument is successful, while it does establish
mental efficacy of a kind, it does not by itself establish the
interaction principle. Establishing that reasons explain actions by
causing them, and that therefore reasons causally interact with
*actions*, does not establish that reasons causally interact
with *physical* events. Dualists who reject the identity of
mental and physical events will surely object.



A key point to grasp in many of the issues raised by Anomalous Monism
is that there is an important distinction between action and behavior.
According to Davidson, action is intentionally described
behavior--the moving of a hand through space in a certain way
may, but need not, be an action of waving or swatting or any action at
all. It may simply be mere bodily behavior--as happens as the
result of a muscle twitch or a strong gust of wind. The behavior must
be caused by an agent's beliefs and desires in order to be
action. However, while this is necessary for action, it is not,
according to Davidson, sufficient. The behavior must be caused *in
the right way* by the beliefs and desires. Davidson notes the
possibility of cases where an agent's beliefs and desires cause
behavior which is not rationalized by those states, and thus not
action. A mountain climber might become so unnerved by his desire to
rid himself of an annoying second climber sharing his rope and belief
that jiggling the rope is a means for doing so that he unintentionally
jiggles the rope, leading to the loss of the second climber. This is
not an action--it is mere behavior that happens to him, no
different than if caused by a muscle twitch or gust of wind. It is
caused *in the wrong way*--a "deviant causal
chain"--by the belief and desire, and so is not an action.
Davidson is skeptical about the possibility of cashing out what it
means to be *caused in the right way* (Davidson 1973b,
78-9), for reasons relating to mental anomalism (Davidson 1973b,
80; see
 4
 for explicit discussion). The key point for now is that because
Davidson rejects the possibility of analyzing action in terms of
behavior caused in a particular way by reasons, the point made by the
'because' argument cannot be used to establish that mental
events cause physical events. It does not follow from the fact that
reasons must cause *actions* in order to explain them that
reasons must cause *behavior* or (the interaction principle)
that reasons *do* cause behavior. It does not entail that
actions *are* physical behavior.



This point is important when one considers the wider framework to
which the interaction principle contributes. Since Davidson is
attempting to derive monism from it and other principles that are
themselves neutral about the metaphysics of mind, he cannot assume
that action is (identical with) behavior on pain of circularity. Once
monism has been established, Davidson will be in a position to deploy
the 'because' point in order to argue for the claim that
mental events are causally efficacious with respect to physical
events. How this relates to the wave of epiphenomenalist criticism
about Anomalous Monism will be explored in detail below
 (6,
 and see the supplement on
 Mental Properties and Causal Relevance).
 To summarize, the interaction principle is an unargued assumption in
the Davidsonian framework, one that does not assume monism, and the
'because' argument, while important for ruling out
non-causal theories of action, does not itself establish the
interaction principle.


### 2.3 Psychological Anomalism



Davidson uses the interaction principle to establish directly one part
of mental anomalism--*psychological anomalism*, which
denies the possibility of strict, purely psychological laws of the
form
'*M*1 & *M*2 - *M*3'
(Davidson 1970, 224; 1974b, 243). For if physical events causally
impact on mental events, then the mental domain is 'open',
and any laws in which mental predicates figure will have to take this
into account (for related discussion, see the supplement on
 Causal Closure of the Physical in the Argument for Anomalous Monism).
 More generally, physical conditions will always play some role in any
plausible psychological generalizations, because physical intervention
(e.g., injury) is always a possibility and can prevent the occurrence
of the consequent '*M*3'. Thus, the only
*potentially* true and strict laws in which psychological
predicates can figure are variants of the psychophysical form
'*P*1 & *M*1 & *M*2 - *M*3'.
*Psychophysical anomalism*, the other component of mental
anomalism and the one that denies the possibility of such strict laws,
is thus the view that Davidson focuses on establishing.


## 3. Premise II: The Cause-Law Principle



The cause-law principle states that events related as cause and effect
are covered by strict laws. In the earliest formulations of Anomalous
Monism, Davidson assumed but did not argue for this principle. His
later argument in support of it will be considered below
 (3.2),
 along with objections to the principle
 (3.3).
 But we need to consider the nature of the requirement contained in
this claim, and how it relates to the framework out of which Anomalous
Monism is deduced.


### 3.1 Strict Laws



The nature of the strict laws required by the cause-law principle is
as follows. For any causal relationship between particular events
*e*1 and *e*2, there must be a law
of the form
'(*C*1 & *D*1) - *D*2',
where '*C*1' states a set of standing
conditions, and '*D*1' is a description
of *e*1 that is sufficient, given
*C*1, for the occurrence of an event of the kind
'*D*2', which is a description of
*e*2. Traditionally, a strict law has been thought
of as one where the condition and event-types specified in the
antecedent are such as to *guarantee* that the condition or
event-types specified in the consequent occur--the latter
*must* occur if the former in fact obtain. But indeterministic
or probabilistic versions of strict laws are possible as well
(Davidson 1970, 219). The point that distinguishes strict laws is not
so much the guaranteeing of the effect by satisfaction of the
antecedent as the inclusion, in the antecedent, of all conditions and
events that can be stated that could possibly *prevent* the
occurrence of the effect. A strict *indeterministic* law would
be one that specified everything required in order for some effect to
occur. If the effect does not occur when those conditions obtain,
there is nothing else that could be cited in explanation of this
failure (other than the brute fact of an indeterministic universe).
For reasons of simplicity, we will assume determinism in this
discussion, though what is said about strict laws could be carried
over without remainder to strict indeterministic laws.



The cause-law principle is aimed, in the first instance, at laws of
*succession*, which cover singular causal relationships between
events at distinct times. However, as will become clearer below,
mental anomalism also takes in *bridge* laws that would
correlate simultaneous instantiations of mental and physical
predicates as well--such as
'*P*1 - *M*1',
'*M*1 - *P*1',
or
'*P*1 - *M*1'.
Indeed, mental anomalism rejects the possibility of *any*
strict law in which mental predicates figure (where those predicates
figure essentially, and are not redundant)--including (as we have
seen
 (2.3))
 laws formulated with purely mental predicates
('(*M*1 & *M*2) - *M*3'),
as well as laws with mental predicates in either the antecedent or
consequent, such as
'(*M*1 & *M*2) - *P*1'
and
'(*P*1 & *P*2) - *M*1'
and mixed variants of these (see
 4).



The denial of strict laws of these forms is consistent with allowing
hedged versions of them which are qualified by a *ceteris
paribus* clause. 'All things being equal' or
'under normal conditions', such psychological and
psychophysical generalizations can, according to Davidson, be
justifiably asserted (Davidson 1993, 9). As will be discussed below
 (4),
 denying the strict version of these generalizations amounts to
denying that the qualifying clause '*ceteris
paribus*' can be fully explicated. That is,
'*ceteris paribus*,
((*M*1 & 
*M*2) - *P*1)'
cannot be transformed into something like
'(*P*2 & *P*3 & 
*M*1 & *M*2 & *M*3) - 
*P*1' (for a related discussion of this
particular issue, see the debate between Schiffer 1991 and Fodor
1991).



(Davidson organizes his discussion of this transformation process, and
Anomalous Monism more generally, around a distinction between
'homonomic' and 'heteronomic' generalizations
(Davidson 1970, 219). That distinction is extremely problematic for
the purposes of establishing Anomalous Monism, and is set aside here
in favor of the related (but by no means identical) distinction
between strict and *ceteris paribus* generalizations. For
discussion of the former distinction, see the supplement on
 Homonomic and Heteronomic Generalizations.)


### 3.2 Justifying the Cause-Law Principle



Davidson argues for the cause-law principle--that singular causal
relations require strict covering laws--on the basis of a
conceptual interconnection between the concepts of *physical
object*, *event* and *law*. As he says, "our
concept of a physical object is the concept of an object whose changes
are governed by laws" (Davidson 1995a, 274). The
interconnections are established partly in response to C.J.
Ducasse's attempt, in reaction to Hume's regularity theory
of causation, to define singular causal relations without appeal to
covering laws (Ducasse 1926).



Simply put, Ducasse defined some particular event *c* as the
cause of some effect *e* if and only if *c* was the only
change occurring in the immediate environment of *e* just prior
to *e*. The striking of the match is the cause of the flaming
match just insofar as the striking is the only change occurring in the
immediate vicinity of the flaming match just prior to the flaming of
the match. Ducasse intended this definition to rebut Hume's
claim that singular causal relations between particular events must be
analyzed in terms of regularities between types of events (and thus
laws). Indeed, Ducasse claimed that Hume was wrong to deny that we
have the ability to perceive singular causal relations--this
denial being the basis for Hume's subsequent regularity account
 (see 3.3).
 For, according to Ducasse, we can perceive that some event is the
only change in the immediate environment of some subsequent event just
prior to that event's occurrence. (We can, of course, be wrong
in thinking that this is what we have in fact perceived. But as
Ducasse points out, the same problem plagues Hume's own
account--we can be wrong that what we have perceived are
instances of types which bear a regular relation to each other. But
this does not lead Hume to hold that since we can't infallibly
perceive that some succession is an instance of a regularity, we
cannot form the concept of causality in terms of regularity. The same
thus applies to Ducasse's own account.)



Davidson notes the heavy dependence, in Ducasse's account, on
the notion of a 'change'. And he asks whether we really
have a purchase on this concept absent appeal to laws. There are two
aspects of this concern. First, the notion of 'change' is
short for 'change of predicate'--a change occurs when
a predicate true of some object (or not true of that object) ceases to
be true (or comes to be true) of that object. And this leads directly
to questions about how predicates are individuated and their
relationship to laws (see below). Second, and at a more general level,
the notion of 'change' has itself changed over
time--for instance, Newtonian mechanics defines a change
differently than Aristotelian physics, so that continuous motion
counts as a change, and thus requires an explanation, according to the
latter but not the former. Thus, the very notion of
'change' is theory dependent, and therefore (Davidson
holds) presupposes the notion of 'law', in the sense that
something counts as a change, and thus as having a cause, only against
a background of theoretical principles.



This second point does not appear to deliver the result Davidson is
after--establishing that each causal interaction must be covered
by a particular strict law. The claim that something is a change, and
thus has a cause, only if certain theoretical assumptions are in place
is consistent with the claim that those assumptions (for instance,
that uniform rectilinear motion does not count as a change) cannot
play the explanatory role for specific causal interactions that strict
laws are supposed to play. They are simply of too general a
nature--they don't enable predictions or explanations of
any particular events. And in any case, there appears to be nothing in
Davidson's considerations here that forces the requirement that
the covering laws be strict as opposed to irreducibly *ceteris
paribus*. (As we have already seen
 (3.1),
 Davidson himself has insisted upon the legitimacy and ubiquity of
such laws in scientific explanation.)



Returning to the first point about predicate-individuation, Davidson
claims that "it is just the predicates which are projectible,
the predicates that enter into valid inductions, that determine what
counts as a change" (Davidson 1995a, 272). We know from Nelson
Goodman's 'new riddle of induction' (Goodman 1983)
that we can invent predicates, such as 'grue' and
'bleen' (where an object is grue if it is green and
examined before 2020 or otherwise blue, and an object is bleen if it
is blue and examined before 2020 or otherwise green) so that a green
object goes from being grue to bleen over the course of time without
having changed in any intuitive sense. It will continue to be green,
though it will also be true that it ceases to be grue and comes to be
bleen. Contrary to much discussion of Goodman's riddle, Davidson
holds that such unusual predicates can be projectible, and figure in
laws, but only when appropriately paired with other such predicates (
"All emeralds are grue" is not lawlike, but "All
emerires are grue" is (where "emerire" is true of
emeralds examined before 2020 or otherwise sapphires ). What is
crucial for Davidson is that to understand the notion of change, which
is so closely tied to the notion of causation, one must understand the
notion of a projectible predicate--one appropriate for use in
science--and this notion inevitably brings in the notion of law.
Changes are described by predicates suitable for inclusion within
laws. But how does this relate to the cause-law principle? Once again,
it is unclear why Davidson would think that it is the notion of a
*strict* law in particular that this line of argument
motivates.



A related line of argument that Davidson offers (see
 4.3)
 appears to suggest that dispositional predicates--those defined
in terms of the effects they tend to bring about--are not
suitable for inclusion in strict laws (generalizations in which they
figure are always qualified by a *ceteris paribus* clause), but
there must be strict laws at the bottom, so to speak, of the
dispositional vocabulary. Davidson's discussion of this issue
refers back to an older debate about the status of dispositional
terms--specifically, whether they are 'place-holders'
for predicates that are non-dispositional ('intrinsic' or
'manifest') (see Goodman 1983, 41ff). Whatever one's
view about that issue, it again does not appear that Davidson has
provided adequate argument for establishing that *strict* laws
(as opposed to *ceteris paribus* laws) are required for our
dispositional vocabulary to operate as it does. So Davidson does not
appear to have provided the cause-law principle with a plausible
rationale (for skepticism about the principle, see Anscombe 1971,
Cartwright 1983, McDowell 1985, Hornsby 1985 and 1993, and
 3.3 below).
 This is not to say that it is false, or even that it is implausible
to assume it in his argument for Anomalous Monism. Many find the
principle highly intuitive, and it is worthwhile to explore its
relation to the other central claims in Davidson's
framework.


### 3.3 Objections to the Cause-Law Principle



The cause-law principle has come in for a lot of criticism since it
received its canonical formulation in Hume's regularity theory
of causation, and it is worth briefly reviewing some of the central
objections relevant to Davidson's own discussions. This will
make clear how important it is, for an argument such as
Davidson's for Anomalous Monism, that some justification for the
thesis ultimately be provided.



An initial objection is that Hume's analysis of singular causal
statements ('*a* caused *b*' is true if and
only if 'whenever an *A* occurs, it is followed by an
occurrence of a *B*'), which articulates his own version
of the cause-law principle, is not an accurate rendering of the way in
which we typically use the term 'cause'. We are confident
in judgments such as 'Harry's smoking caused his lung
cancer' while knowing that in fact not all smokers are stricken
by lung cancer. This point is entirely general--we make singular
causal judgments all the time without believing in (indeed, while
knowing the falsity of) the associated universal generalization (see
Anscombe 1971). However, Davidson's extensionalism about
causality provides a straightforward response to this concern. His
view is that while we may not believe in the associated universal
generalization, that is consistent with there being *some*
universal generalization, stated in a different vocabulary than the
singular causal statement, which 'covers' that statement.
(It is worth noting that Davidson rejects Hume's
*analysis* of singular causal statements in terms of universal
generalizations--he holds that the requirement of such a covering
generalization is necessary but not sufficient for the truth of such a
statement (Davidson 1967).)



While this response does appear to meet the objection, it raises the
following concern, which is behind a related objection to the
cause-law principle: no one in fact seems to know any true predictive
'strict' laws (in the literal sense of that term). Now,
while it is certainly consistent with this point that there are or
even must be such laws, it becomes more pressing to know why we should
think this if we cannot even offer any examples. It is well and good
for Davidson to point to the possibility of strict covering laws that
transcend our current knowledge, but we need to know why we should
believe in such things. Science seems to have done well for itself
without any apparent use of them.



Another objection to the cause-law principle comes from the state of
contemporary physics. According to quantum mechanics, it is not simply
difficult or impossible for us to state such laws for quantum
phenomena. Rather, quantum theory appears to entail that determinism
fails to obtain at the level of microparticles. What the theory and
the behavior of such particles tells us is that causation, at least at
the level of micro phenomena, is indeterministic. And this
indeterminism is claimed to be inconsistent with the requirement of
strict laws. This objection to the cause-law principle, then, is that
philosophy should never dictate to science on empirical matters.
Observation of the world tells us that strict laws are impossible in
this domain even while causation is present, in direct contradiction
of the cause-law principle.



Now, we have already seen Davidson's own response to this sort
of objection
 (3.1).
 As traditionally construed, strict laws are supposed to guarantee the
consequent condition on the basis of the antecedent condition. But
they do not need to provide such a guarantee. What strict laws require
is that the antecedent include all conditions and events that could
possibly prevent the occurrence of the consequent. If the consequent
does not occur when all these conditions have been accounted for,
there is nothing else to be cited in explanation of the non-occurrence
other than the sheer brute fact of an indeterministic universe. So
indeterministic causation is entirely consistent with the cause-law
principle (Davidson 1970, 219). The determinist/indeterminist and
strict/nonstrict law distinctions do not map neatly onto each other.
An indeterministic law can be universal, exceptionless and true. This
point does not appear to be recognized by central proponents of the
indeterministic objection to strict laws (see Cartwright 1983).



A final objection to the cause-law principle which is more internal to
the wider framework of Anomalous Monism has been put forth in McDowell
1985. McDowell sees a tension between Davidson's allegiance to
the cause-law principle and his rejection of 'the dualism of
scheme and content' (Davidson 1974a). Briefly, the dualism
Davidson opposes is the idea that, for instance, a perceptual judgment
is the rational upshot of an interaction between a concept and an
nonconceptualized experiential element--the sensory input. Given
Davidson's systematic rejection of this idea, McDowell believes
he ought to disavow the cause-law principle. McDowell doesn't
think the principle is required for a minimal version of materialism
(see the supplement on
 Related Views
 (Bare Materialism), and without the need to justify materialism
McDowell sees the principle as lacking any motivation in
Davidson's framework. For discussion of this issue and others
related to scheme-content dualism and Anomalous Monism, see the
supplement on
 Related Issues
 (Anomalous Monism and Scheme-Content Dualism).


## 4. Premise III: The Anomalism Principle



The anomalism principle states that there are no strict laws on the
basis of which mental events can predict, explain, or be predicted or
explained by other events. In this section we look at different
interpretations of the argument for this principle. Davidson's
own formulations, while suggestive, are notoriously vague and often
appeal to very different sorts of considerations, including aspects of
language and interpretation, questions about psychological
explanation, and the nature of causality and dispositions. We shall be
looking at specific interpretations as well as the problems they face
in providing a compelling rationale for both the anomalism principle
and Anomalous Monism.



While differing in important ways, the various formulations of the
argument, as well as the objections to them, exhibit a discernible
pattern: proponents of mental anomalism highlight some feature of
mental properties that is claimed to (1) sharply individuate them from
physical properties and (2) create a conceptual tension with physical
properties that precludes the possibility of strict lawful relations
between these properties. According to the objections, however, the
highlighted feature of mental properties either does not serve to
distinguish it from physical properties or does not actually stand in
any conceptual tension with physical properties that rules out lawlike
relations. We will consider each interpretation, and its problems, in
turn. In a later section
 (5.3)
 we will look at another objection related to the anomalism
principle--that it is inconsistent with Davidson's
invocation of the doctrine that mental properties stand in a relation
of supervenience to physical properties. For discussion of the
relation between the anomalism principle and Davidson's views
about scheme-content dualism and semantic externalism, see the
supplement on
 Related Issues.



Mental anomalism, as initially formulated by Davidson, holds that
there can be no strict laws on the basis of which mental events can be
predicted and explained (Davidson 1970, 208). It is thus restricted to
ruling out strict laws of succession with mental predicates occurring
in the consequent--laws such as
'*P*1 - *M*1',
'(*M*1 & *P*1) - *M*2',
or
'*M*1 - *M*2'.
It thus denies that the occurrence of particular mental events such as
coming to believe or intend something, or intentionally acting in some
way, can be explained by appeal to strict covering laws. But as
becomes clear, Davidson's considered position rejects the
possibility of *any* strict laws in which mental predicates
figure--and this includes, in particular, bridge laws of the form
'*P*1 - *M*1',
which form the basis of type-identity theories of mind, as well as any
strict laws with mental antecedents. We have already seen how strict
purely psychological laws are ruled out by the interaction principle
 (2.3).
 And, at a more general level, it rules out purported solutions to the
problem of deviant causal chains noted in
 2.2,
 which would spell out, in terms of some required physical and also,
perhaps, mental conditions, how behavior must be caused by reasons
("caused in the right way") in order to be action. (That
some physical conditions are necessary in such an analysis is
guaranteed, as we have seen
 (2.3),
 by the open nature of the mental and subsequent psychological
anomalism.) Any such adequate analysis of action would entail
particular psychophysical laws of the form
'(*M*1 & *M*2 & *M*3 & *P*1) - *P*2'.
For such an analysis would state that whatever behavior
(*P*2) which in fact is caused in the right way
(*M*3 & *P*1) by
reasons
(*M*1 & *M*2) would
*be* the action that is rationalized by those reasons. This
provides a schema for generating strict psychophysical laws: by
plugging in particular reasons and the causal conditions
*P*1 and *M*3 proffered by the
analysis, we get a strict predictive psychophysical law simply by
noting what effect is produced by these causes. (In the course of an
extended discussion of the problem of deviant causal chains, Bishop
1989, 125-75, fails to see this connection between it and mental
anomalism--see 164.) With strict purely psychological laws thus
already ruled out, the focus now is on strict psychophysical laws.



It is useful to view Davidson's attack against psychophysical
laws in light of an argument, in vogue in the 1950s and 1960s, against
the claim that reasons are causes of the actions they explain. This
argument was referred to as the "Logical Connection
Argument" (see Stoutland 1970). According to this argument,
reasons cannot be held to explain actions by causing them because (1)
causes and effects must be logically distinct from each other (one of
Hume's requirements on causality) but (2) reasons and the
actions they explain bear a quasi-logical connection to each other, by
virtue of the rationalizing relation between them. That relationship
is quasi-logical because not just any reason can explain any
action--only those reasons which actually rationalize (make
intelligible) an action can explain it. Davidson's own
influential response to this argument was to distinguish between
causal relations, which obtain between events no matter how they are
described, and logical relations, which obtain between particular
descriptions of events. The Logical Connection Argument fails to
recognize this simple distinction. The distinction allowed Davidson to
merge two key ideas in his theory of action--that reasons explain
by causing, and that they explain by rationalizing (Davidson 1963,
13-17). As we shall see below, however, Davidson appears to
accept a basic distinction at the heart of the Logical Connection
Argument--that the rationalizing relationship bears a certain key
property (quasi-logical status) that is at odds with the relationship
between physically described, causally related events.


### 4.1 The Holism/Indeterminacy Arguments



Davidson's explicit considerations in favor of mental anomalism
appeal to factors about the interpretation of action (linguistic as
well as non-linguistic) and the ascription of mental states and events
to persons. Several distinguishable features are noted--holism
with respect to particular ascriptions, indeterminacy with respect to
systematic interpretative frameworks, and the responsiveness of mental
ascription to an ideal of rationality. According to holism, particular
mental states can be cited in explanation of behavior only in the
context of other mental states, which in turn depend upon others.
Davidson claims that this dependency and holistic interrelatedness is
"without limit" (Davidson 1970, 217). This echoes a
related point he makes about the impossibility of definitional
reduction of mental states in purely behavioristic terms, because of
the ineliminable need for mental caveats (e.g., that the person
understands, or notices or cares....) qualifying any attempt to
state non-mental conditions for mental states.



Davidson presents these claims about definitional reduction as facts
which "provide at best hints of why we should not expect
nomological connections between the mental the physical"
(Davidson 1970, 217). If definitional reduction of this kind were in
fact impossible, it would rule out the possibility of a subclass of
strict psychophysical laws--those relating mental states with
non-intentionally described behavior--but the basis for this
impossibility would not have been explained. In fact, however, without
knowing what that basis is supposed to be, we have no reason to accept
Davidson's claim that definitional reduction is indeed
impossible. What prevents us from articulating all the required
caveats? Without a rationale in hand, nothing prevents a reductionist
from simply offering us detailed definitions and challenging us to
come up with counterexamples. Something both principled and convincing
is clearly needed. Davidson's concerns about definitional
reduction are 'hints' concerning nomological reduction
only in the sense that they draw out our intuitions about something
standing in the way of formulating such laws. What that obstacle is
needs clear formulation.



At times, Davidson appeared to flirt with the idea that the missing
link was provided by the thesis of the indeterminacy of translation,
developed by W.V Quine (1960) and endorsed by Davidson (1970, 222;
1979). This thesis claims that there are empirically adequate but
non-equivalent complete frameworks for assigning linguistic meanings
and mental states to a person on the basis of his behavior, and that
there is no fact of the matter that determines that one but not other
such frameworks is correct. In particular, there are no physical
facts, inside a person's body or head or outside in the external
world, that could settle whether a person's words refer to some
determinate range of objects rather than some other range, or whether
one rather than another systematically interdependent set of mental
states, with distinct distributions of truth values, is true of that
person (see Davidson 1979). If the indeterminacy thesis is true, then
on the face of it there would be some rationale for rejecting the
possibility of psychophysical laws. For if all physical facts are
consistent with different psychological/semantic assignments, then it
seems that knowing all the physical facts could not tell us whether
some mental states were true of some person, or some meaning true of
her words--neither could be exceptionlessly predicted or
explained, just as mental anomalism maintains.



There are two problems with this, however. First, this would do
nothing to rule out certain psychophysical laws, such as those of the
form
'*M*1 - *P*1'.
And so it couldn't ground the completely *general* thesis
of mental anomalism. But more importantly, Davidson himself holds that
the least controversial versions of indeterminacy, having to do with
diverging reference schemes, amount to mere notational
variance--as he puts it, meaning is what is invariant between
empirically adequate translation schemes (Davidson 1977, 225; 1999a,
81). And given that such schemes are generated through a purely
mechanical permutation function (Davidson 1979, 229-30) it is a
relatively simple technical trick to take these different schemes into
account when formulating psychophysical laws. The laws, for instance,
could be formulated with disjunctive predicates
('*P*1 - (*M*1 [?] *M*2 [?] *M*3').
Or, if such predicates are considered problematic, the laws could be
of the form
'*P*1 - *M*\*',
where '*M*\*' picks out the invariant element
between the empirically equivalent theories. So it is not at all clear
that indeterminacy in and of itself is capable of supporting an
across-the-board rejection of strict psychological or psychophysical
laws. And Davidson ultimately acknowledges this, in stating that
anomalism would hold even if indeterminacy didn't (Davidson
1970, 222).


### 4.2 The Rationality Arguments



What is responsible for the possibility of indeterminacy, however, is
the role of the principle of charity in formulating a theory of
another person's behavior (Davidson 1970, 222-23). And
this principle is closely aligned for Davidson with mental anomalism.
According to this principle, we must "try for a theory that
finds him consistent, a believer of truths, and a lover of the good
(all by our own lights, it goes without saying)" (Davidson 1970,
222). In the process of coming to understand another, by ascribing
mental states and events to him and meanings to his words, we must,
Davidson claims, stand ready to adjust previous assignments of
meanings and mental states and events based upon new evidence about
the person and how it relates to the overall project of finding him
and his behavior intelligible. There are two key points here that for
Davidson suggest mental anomalism. First, we never have all possible
evidence--we must maintain an openness to better interpretations
of previous behavior as new evidence becomes available. Interpretation
is always ongoing. And second, 'better' interpretations
are those made in light of the constitutive ideal of rationality.
Consequently, Davidson claims, 



> 
> 
> there cannot be tight connections between the realms [of the mental
> and the physical] if each is to retain allegiance to its proper source
> of evidence. (Davidson 1970, 222)
> 
> 
> 



Rationality is claimed by Davidson to be *constitutive* of the
mental in the sense that something only counts as being a
mind--and thus an appropriate object of psychological
attributions--if it meets up to certain rational standards. This
constitutive idea is open to weaker and stronger interpretations. The
weaker interpretation sees only very basic logical, semantic or
conceptual constraints on understanding others--and thus what is
constitutive of minds--which allows for significant variation as
one moves further out from these to more substantive principles of
practical reasoning and theoretical reasoning, and even more when
extending out further to desires and values. The stronger
interpretation appears to be suggested in the quote from Davidson
immediately above. In requiring consistency, true beliefs and
appropriate desires, it appears to require maximizing agreement
between interpreter and interpreted, and thus a maximal conception of
what is constitutive of minds. The weaker interpretation instead
requires merely minimizing inexplicable error on the part of the
creature being interpreted, thus allowing for significant deviations
from psychological assignments that might be required by the stronger
interpretation. On this view, the interpreter puts himself into the
shoes of the interpreted, acknowledging evidential and cognitive
limitations that might prevent her from achieving maximal rationality
(Grandy 1973). As we will see in this section, how one interprets the
notion of rationality as constitutive directly affects how the
argument for mental anomalism is interpreted to work.



While Davidson never offers any substantive account of what the proper
source of evidence is for the physical, he often invokes the notion of
rationality as constraining mental ascription, and it is clear that
whatever constrains physical ascription is supposed to pull in a
different and potentially conflicting direction. One suggestive way of
getting at Davidson's idea here is through the traditional
distinction between 'normative' and
'descriptive' concepts. When we look to uncover
generalizations in the physically described world, what we find to
follow from a certain set of physical conditions is a *brute
fact*; our world is constituted in certain ways (in its governing
laws) that we could imagine to be different. We may come to an
empirical investigation with certain theoretical commitments that
inevitably lead us to read the data in some ways rather than others;
and there may indeed, as Davidson himself suggests, be constitutive
*a priori* principles that govern very basic physical concepts
such as 'object' and 'event' (Davidson 1970,
220; 1974b, 239; 1973a, 254; see
 3.2
 above). However, the constraints are far looser and allow for a wide
variation in terms of empirical content--of what physical events
and states can follow from others. This is contrasted with mental
ascription, where the normative notion of rationality rules out the
possibility of certain mental states following from others. This line
of thinking is suggestive, but it is in need of considerable
tightening.


#### 4.2.1 Normative vs. Descriptive Principles (Kim)



Jaegwon Kim's account of Davidson's position (Kim 1985)
attempts to do just this. Kim argues that if there were strict lawlike
relations between mental and physical predicates, the 'brute
factness' and contingency of the physical would
'infect' the mental. For instance, rationality
considerations will typically lead us to attribute a belief that q to
a person if we attribute a belief that *p* and also attribute a
belief that p entails q. According to Kim's account, beliefs
involving very basic logical, semantic or conceptual relations like
this hold of necessity--we cannot make sense of possible worlds
where beliefs of the first two kinds are attributed but not the
third.



Now, this may appear to be too strong a claim, in light of
Davidson's rejection of strict, purely psychological
laws--mental anomalism rejects the possibility of any strict laws
in which mental predicates figure, but Kim here appears to be
deploying laws of the form
'*M*1 & *M*2 - *M*3'.
Kim would reply that Davidson is only interested in rejecting strict
descriptive (i.e., explanatory, predictive) laws, not strict normative
laws (see below). 



If physical predicates stood in strict lawful relations to mental
predicates, this contingency would 'infect' the mental in
the following sense. Suppose that there were strict bridge laws
correlating the instantiation of mental and physical properties,
'*P*1 - *M*1'
and
'*P*2 - *M*2'.
Then, Kim argues, rational principles of the form
'*M*1 - 
*M*2' would enable the logical derivation of
physical laws like
'*P*1 - *P*2'.
Indeed, the reverse would be true as well; starting with the physical
law
'*P*1 - *P*2',
and assuming the psychophysical bridge laws, one could derive the
rational principle
'*M*1 - *M*2'.
However, the metaphysical status of the rational principle and the
physical law are importantly different--rational principles are
necessary, true in all possible worlds, while physical laws, being
contingent, are not. In particular, with the bridge laws in place, a
contingent physical law could explain (through derivation) the
rational principle, undermining its status as necessary. Since it is
the bridge laws that enable these troublemaking derivations,
they--and thus strict psychophysical laws--are to be
rejected. This is how Kim makes sense of Davidson's suggestive
claim that mental anomalism is grounded in the fact that mental and
physical explanation owe their allegiance to different sources of
evidence. (For related discussion, see the supplement on
 Explanatory Epiphenomenalism.)



Kim's argument rests upon two central assumptions. First, it
assumes that no distinction between strict and *ceteris
paribus* laws need play any role in reconstructions of
Davidson's argument. It is, purportedly, not the *scope*
of a psychological law which accounts for an asymmetry with physical
laws, but rather the *point* of each type of law (Kim 1985,
381). Second, it assumes that there is a firm distinction between
descriptive laws and relations, on the one hand, and normative laws
and relations, on the other, that can bear the weight of mental
anomalism (Kim 1985, 383) The first assumption is clearly mistaken; as
already noted, Davidson heavily emphasizes the focus on strict laws in
his own discussions of Anomalous Monism, and explicitly allows for the
possibility of hedged laws incorporating mental predicates.
Kim's *reductio* strategy, then, would fail to uniquely
identify the culprit responsible for producing the trouble as the
bridge laws rather than the rational principle, *all* of which
are strict. And while Davidson does emphasize the normative status of
mental predicates, he also recognizes, as we have already noted
 (3.2
 and
 4.2),
 a normative component to the physical realm, in constitutive *a
priori* principles. There does not appear to be a significant
distinction between descriptive and normative principles in
Davidson's framework that can bear the burden of mental
anomalism, as required on Kim's interpretation. (For further
discussion of Kim's interpretative strategy, see the supplement
on
 Kim's *Reductio* Strategy for Establishing Mental Anomalism.)


#### 4.2.2 Uncodifiability and Strong Rationality as An Ideal (McDowell)



John McDowell also focuses on the normative nature of rationality, but
emphasizes a very strong conception of rationality as an ideal
constitutive of the mental, taking in more than merely the familiar
deductive relations--logical, semantic or
conceptual--deployed in Kim's reading (McDowell 1985,
391-4). McDowell appears to be guided by some of
Davidson's broader formulations and discussions of the principle
of charity
 (4.2),
 which extend to more general principles governing action and belief
formation, highlighted in Davidson's discussions of
irrationality (see Davidson 1982). For example, the principle of
continence requires one to act on the basis of all available
considerations, and the principle of total evidence requires one to
believe the hypothesis supported by all of one's evidence. And
the broad formulations entail that our conception of rationality
includes conceptions of the Good, and so the formation of rationally
appropriate desires, thus extending beyond constraints on belief and
action. According to McDowell, those inclined to think that mere
deductive relations can be captured in physical terms (see Loar 1981)
will find mental anomalism much more difficult to deny when taking
into account this stronger conception of rationality. 



This stronger conception of rationality puts McDowell in a position to
exploit a crucial gap between rational norms and actual explanations
of behavior:



> 
> 
> Finding an action or propositional attitude intelligible, after
> initial difficulty, may not only involve managing to articulate for
> oneself some hitherto merely implicit aspect of one's conception
> of rationality, but actually involve becoming convinced that
> one's conception of rationality needed correcting, so as to make
> room for this novel way of being intelligible. (McDowell 1985,
> 392)
> 
> 
> 



Just as our beliefs about empirical matters can be mistaken in any
given case, and we can make genuine discoveries about empirical
reality, just so with rationality. Clearly this claim is much more
plausible with the stronger conception of rationality that McDowell is
urging than the weaker conception limited to mere deductive relations.
McDowell goes on to argue that because of this feature, we must be
open to the possible reinterpretation of a person's behavior and
psychological states in light of our changing conception of
rationality, and how it changes cannot be anticipated in advance so
that rationality could be captured in a permanent set of principles
from which strict laws could be fashioned. For this reason,
rationality is *uncodifiable*. According to McDowell, this is
what underlies mental anomalism.



One might understand the reasoning here in the following way: because
it is built into our conception of rationality that our own particular
grasp of rationality may be mistaken on any given occasion and is also
inherently limited, no statement of psychological or psychophysical
generalizations could exhaust, and therefore explain, our conception
of rationality. If *the* concept of rationality does not simply
consist in *one's* conception, at any given time, of
rationality, then it cannot be captured in terms of the
*actual* goings on in one's brain (the same point applies
if we substitute "everyone's" for
"one's"). Therefore, strict lawlike relations
between the mental and the physical are impossible. This contrasts
interestingly with Kim's strategy: on McDowell's reading,
it is partly because no detailed statement of a rational principle
*could* be claimed to be necessarily true that there can be no
psychophysical laws.



A number of questions arise in considering McDowell's argument.
It appears to be heavily influenced by Davidson's remarks about
the ongoing nature of interpretation (Davidson 1970, 223;
 see 4.2).
 However, Davidson appeals to the fact that new
*evidence*--in the form of behavior and environmental
context--is always coming in that can force us to revise existing
interpretations of an agent. There is no mention of shifting
*standards*, or unarticulated or inarticulable conceptions of
rationality. Indeed, the implication is that a *stable*
standard, when taking into account new evidence, can lead to revised
interpretations of prior behavior. So McDowell appears to be going
beyond Davidson's own views about the concept of rationality.
Indeed, the idea that one is not able to fully articulate a concept in
the way suggested by McDowell--that it is in effect
*ineffable* -does not clearly sit comfortably with
Davidson's views about conceptual relativism and rejection of
the idea of untranslatable languages (see further the supplement on
 Related Issues
 (Anomalous Monism and Scheme-Content Dualism).



Further, and more importantly, McDowell's distinctive
uncodifiability claim, which rests on this view of rationality, looks
to be too general to underwrite a specific thesis like mental
anomalism. This becomes apparent when one asks why the very same
features that he is insisting are true of our conception of
rationality aren't also true of the key concepts that figure in
explanations of the physical world. Surely our concepts of physical
reality outstrip any particular conception we have at any given time,
and the possibility of mistaken application is built into them. And
scientists are in the same position as interpreters in terms of the
possibility of new evidence and its bearing on how previous evidence
was understood. So far this looks to be nothing more than a
combination of a completely general point about concepts together with
the familiar problem of induction, which plagues all empirical
enquiry. McDowell's assertion that "someone who aims at
explanations of the ideal-involving kind must be alive to the thought
that there is sure to be a gap between actual current conception and
ideal structure in his own case as well as others" (McDowell
1985, 392) doesn't appear to uniquely pick out any particular
explanatory framework. It therefore cannot tell us anything
distinctive about the metaphysical status of psychology.



If, however, the emphasis here falls on *constitutive*
principles in particular--as surely it must--then two other
problems arise. First, McDowell's reasoning doesn't tell
us what exactly it is about such principles that makes them resistant
to reduction, since, as we've just seen, that reasoning has
failed to distinguish them from empirical concepts in the physical
sciences. And second, as noted in
 4.2,
 Davidson holds that there are constitutive *a priori*
principles underlying the physical sciences which play a similar role
there that rationality plays in psychological explanation. So we are
still in need of an explanation of why psychology and physics cannot
stand in strict lawlike relations. Now, we did note there that such
physical constitutive principles are far more lenient than
rationality, allowing for a greater variety of empirical
content--of what can follow from what. This indeed accounts for
an important asymmetry between mental and physical explanation. And
McDowell heavily emphasizes this point in his discussion: that it is
not merely a brute fact that rationality marks the limits of
intelligibility, while physical explanations do bottom out in brute
facts (McDowell 1985, 394). However, this point appears to be entirely
separable from the distinctive feature of McDowell's reading of
the argument for mental anomalism--it has nothing especially to
do with the idea of rationality as *uncodifiable* in
McDowell's specific sense. In fact, it is the key point behind
Kim's strategy, and it appears to have no essential connection
to McDowell's stronger views about rationality. One can think of
rationality as constitutive, as normative and as asymmetrical to the
physical in the way just noted--as Kim does--without buying
into McDowell's distinctive picture of it. So it looks like the
salvageable part of McDowell's actual argument for mental
anomalism ultimately reduces to Kim's. Uncodifiability appears
to be a red herring.



Therefore, despite McDowell's extremely subtle and interesting
views about the nature of the ideal of rationality, in the end those
views do not appear to provide a secure foundation for mental
anomalism. It is only what is shared in common with Kim's
strategy--the modal asymmetry between rational and physical
explanation--that bears directly on mental anomalism. And that
leaves McDowell's reading facing the sorts of concerns raised in
 4.2.1.


#### 4.2.3 The Context/Complexity Argument (McDowell and Child)



As we have seen above, Kim thinks that mental anomalism is susceptible
of a kind of proof. This seems to be something stronger than Davidson
himself claims (Davidson 1970, 215). In light of Davidson's
modesty about provability, and lack of explicit argumentation, some
commentators (Child 1992; see also McDowell 1979) have suggested that
mere reflection on the kinds of generalizations that we draw upon in
coming to understand each other supports (but cannot prove) mental
anomalism. Such generalizations are rules of thumb that hold only for
the most part, and require, for their application to a given case,
detailed contextual supplementation that cannot, by its nature, be
included in anything like a universal generalization. The suggestion
is that the sheer amount of contextual detail that would need to be
accounted for in any statement with even a hope of being true is
inappropriate for inclusion in strict lawful statements. A related
strategy is to point to a lack of fixed, predetermined ends that all
humans (or even any particular human over the course of her life) aim
for in situations of choice, or values to maximize when deciding what
to believe (such as simplicity, scope, and consistency in the case of
theory choice) (Child 1992). The thought here is that if there are no
such fixed ends or values, then no psychological generalization could
be complete--since in particular contexts such ends or values
play a crucial explanatory role in determining what to do or
believe.



It would seem, however, that reflection on the level of detail
required for strict laws in the physical sciences fails to provide for
an interesting asymmetry here. If one considers the number of factors
that would have to be taken in to account in order to state conditions
that guarantee that when a match is struck it will produce a flame,
the resulting strict law would be quite complex, and in a way not
obviously different from any putative strict laws in which mental
predicates figure, with contextual features included. And if there are
indeed no fixed ends or values in the realm of choice and a decision,
this can be accommodated in the same way--the contextual ends or
values could themselves be included in the putative strict laws. This
would complicate and expand the set of such laws, but as already noted
this is not something that would set mental generalizations apart from
physical ones. (For further discussion of rationality and the argument
for Anomalous Monism see Yalowitz 1997 and Latham 1999.)


### 4.3 The Causal Definition Argument



We have been looking at different ways of making sense of and
justifying Davidson's claim that mental anomalism stems from the
constitutive role of rationality in mental ascription. In
Davidson's writings, however, another line of argument often
surfaces which focuses less on the rational nature of mental events
and more on their causal nature. As we have already seen, in his
earliest work on action Davidson argued that reasons explain actions
by causing them, and he later came to emphasize that what makes mental
states and events what they are is determined in part by their causes
and effects. Particular psychological explanations are causal (they
invoke causes--Davidson 1963), and are formulated in terms of
causally defined concepts (for propositional attitudes, see Davidson
1987b, 41; for mental contents, see Davidson 1987a, 44). In later work
he frequently notes the anomic nature of causal concepts and causal
explanations, and how mental properties and reasons explanations are
anomic because of this--"reason-explanations...are in
some sense low-grade; they explain less than the best explanations in
the hard sciences because of their heavy dependence on causal
propensities" (Davidson 1987b, 42; see also Davidson 1991, 162).
If mental concepts are causally defined, and strict laws do not employ
causally defined concepts, then mental anomalism appears to follow
straight away, without need of any detour through issues concerning
the rationality of mental concepts.



Extending this reasoning, Davidson writes that



> 
> 
> [m]ental concepts...appeal to causality because they are
> designed, like the concept of causality itself, to single out from the
> totality of circumstances which conspire to cause a given event just
> those factors that satisfy some particular explanatory interest.
> (Davidson 1991, 163)
> 
> 
> 



This appears to ground the causal definition of anomic properties
(whether mental or otherwise) in the fact that they answer to
particular explanatory interests. This is contrasted with the case of
'ultimate physical' properties: "Explanation in
terms of the ultimate physics, though it answers to various interests,
is not interest relative" (Davidson 1987b, 45). This seems to
collapse the distinction between psychology and all the other special
sciences with respect to the question of anomalism. All of the latter
answer to particular explanatory interests, and are thus
*selective* with respect to the total sufficient condition for
an effect-type (see Davidson 1987b, 45); the causal definition, and
thus anomalism, of their vocabularies is owed to this
interest-relativity and selectivity. 'Ultimate physics',
on the other hand, "treats everything without exception as a
cause of an event if it lies within physical reach (falls within the
light cone leading to the effect)" (Davidson 1987b, 45).



Davidson repeats these sorts of claims about the anomic nature of
causally defined properties in a number of places in later writings,
but at no point does he clearly bring them into contact with his early
remarks concerning the constitutive role of rationality in
psychological ascription. And he never provides argument in support of
this general thesis concerning causality. It is natural to wonder why,
given this general thesis about causally defined concepts, rationality
should be thought to underwrite mental anomalism. And it becomes
imperative to know why that general thesis is plausible (for
discussion, see Yalowitz 1998a).



With regard to the first issue, there is some evidence that Davidson
is confusing two distinct questions: why mental concepts cannot stand
in lawlike relation to physical concepts, and why mental concepts
cannot be eliminated in favor of physical concepts in the explanation
of human behavior. Given the general thesis about causally defined
properties, we have an understanding of why mental concepts are
anomic. But this leaves open the question whether we ought to continue
to traffic in anomic concepts generally, and mental concepts in
particular. Why not eliminate them in favor of the nomic physical
concepts? Here, the rationality of mental concepts may be thought to
provide an answer. If we wish to understand why an agent performed the
action that she did, as opposed to having a full sufficient causal
explanation of why her body moved as it did, we are interested in a
selective explanation--that part of the total sufficient
condition that satisfies the particular explanatory interests behind
reasons-explanations (Davidson 1991, 163). Those interests highlight
the normative nature of reason and action--their responsiveness
to the principle of charity and ideal of rationality. Rationality, on
this line of thinking, does not account for mental anomalism; but it
does speak to the question of mental realism (see further
 6.2).
 (For further discussion of the anomic nature of causally defined
concepts and its bearing on Anomalous Monism, see Yalowitz 1998a. For
more on the relation between rational explanation and mental realism,
see the supplement on
 Explanatory Epiphenomenalism.
 For discussion of issues closely related to the causal definition
argument, see
 6.3
 and the supplement on
 Related Issues
 (Mental Anomalism and Semantic Externalism).


## 5. Monism



So far we have looked at Davidson's three premises in support of
Anomalous Monism--the interaction, cause-law and anomalism
principles. In this section, we examine the conclusion that Davidson
draws on the basis of these principles--the token-identity theory
of mental events, according to which every causally interacting mental
event is token-identical to some physical event. We will look at the
derivation and nature of this theory, some questions about its
adequacy, as well as the additional thesis that mental properties
supervene on physical properties. As we shall see, both the
token-identity and supervenience claims turn out to be controversial,
in their motivation as well as in their consistency with mental
anomalism. One key point to keep in mind at this point is that monism
is supposed to be derived from the principles and other assumptions
that, taken individually, could be acceptable to positions opposing
monism.



To begin with, it is worth pointing out that Davidson is concerned
only with the ontological status of events, and not substances.
Descartes, for instance, argued for the claim that mind and body are
distinct entities. While Descartes' position has implications
for accounts of mental events, the issues concerning event and
substance identity are distinct (see Latham 2001). Davidson clearly
takes himself to be establishing something that is inconsistent with
Cartesian dualism, however, and it is useful briefly to look at how
Anomalous Monism bears upon substance dualism.



According to Descartes, mind and body are distinct substances in part
because they do not share essential properties in common. In
particular, minds do not occupy a spatial location, while bodies
necessarily do. Since mental events thus constitute changes occurring
in a nonspatially-located entity, they also do not occupy a spatial
region. Bodily events, on the other hand, do occupy spatial locations
by virtue of being changes in material substances, which themselves
are spatially located. On Descartes' view, then, particular
mental and physical events cannot be token-identical, since they fail
to share a crucial property in common without which identity is
unintelligible. While Anomalous Monism is not officially concerned
with the ontological status of substances, it thus appears to have
consequences that are inconsistent with Descartes' substance
dualism--though it doesn't by itself establish substance
monism, it does rule out the Cartesian thought that mental and
physical events fail to be identical, and so conflicts with one of the
bases for Cartesian substance dualism.


### 5.1 Token Identity



The structure of Davidson's derivation of the token-identity of
causally interacting mental events with physical events appears to be
straightforward: causally interacting mental events (the interaction
principle) must instantiate some strict law property (the cause-law
principle) but mental properties are not suitable for inclusion in
strict laws (the anomalism principle). So mental events must
instantiate some other property, which is suitable for such inclusion.
Given Davidson's invocation of the causal closure of the
physical domain, according to which every physical event has a
physical explanation, he moves rather quickly to the conclusion that
this other property must be physical, since closure entails that
physical properties have a privileged status, which suggests that they
hold out the promise of strict laws. (Davidson also has a tendency
simply to identify as 'physical' those properties that
figure in strict laws (Davidson 1970, 224; 1995a, 266), but this would
of course beg the question of mental anomalism.) Consequently,
causally interacting mental events must be token-identical with
physical events, ruling out Cartesian as well as other forms of
dualism.



There are serious problems with the assumption of causal closure of
the physical in Davidson's framework (for discussion, see the
supplement on
 Causal Closure of the Physical in the Argument for Anomalous Monism).
 It is difficult, however, to see how Davidson can move from the claim
that mental events must instantiate non-mental, strict law properties
to the claim that these properties must be physical without assuming
closure. Why assume that only 'physical' properties are
nomic? This raises interesting issues about the nomic status of other
special sciences--the relevant ones here being biology and
chemistry--but there do not appear to be explicit, conclusive
resources in Davidson's own thinking for addressing this.
Yalowitz 1998a has, however, provided an interpretation of Anomalous
Monism stressing Davidson's views on causality and the nomic
status of dispositions (see
 4.3)
 in which causal closure is *derived* *from* the
cause-law principle, token-identity and the anomalism of causally
defined properties. On this interpretation, the strict law properties
that mental events must instantiate turn out to be physical because
only physical properties are non-causally individuated--all
special science properties are causally individuated, and all such
properties are anomic.



Davidson's token-identity theory is dramatically different than
previous identity theories of mind, in both it's *a
priori* status as well as its stance towards the role of laws in
justifying monism. Previous theories had argued that claims concerning
the identity of particular mental and physical events depended upon
the discovery of lawlike relations between mental and physical
properties. These theories thus held that empirical evidence
supporting such laws was required for particular identity claims.
According to Anomalous Monism, however, it is precisely
*because* there can be no such strict laws that causally
interacting mental events *must* be identical to some physical
event. The token-identity thesis thus requires no empirical evidence
and *depends* on there being no lawlike relations. It in effect
justifies the token-identity of mental and physical events through
arguing for the impossibility of type-identities between mental and
physical properties or kinds (Davidson 1970, 209, 212-13; see
Johnston 1985).



An important point to recognize in Davidson's version of
token-identity is that he is not simply deriving the conclusion that
mental events bear some property that we would intuitively acknowledge
as 'physical' (such as spatial location). As pointed out
in
 2.1,
 the relevant 'physical' properties would more likely have
to resemble the sorts of properties currently invoked in physics, our
most mature science and the one closest to issuing in strict laws.
This point has generated numerous objections to Davidson's
token-identity theory, but it also has been overlooked by some
objectors (see below). Davidson's central claim is that what
makes a mental event identical to a physical event is that the mental
event has a physical description. In Davidson's original
formulation, monism entailed that every mental event can be
*uniquely* singled out using only physical concepts (1970,
215). It is this position that became the target of some
Davidson's critics
 (5.2).
 However, Davidson eventually came to explicitly deny that his monism
commits him to the possibility of providing descriptions of mental
events or actions in physical terms suitable for strict laws (Davidson
1999d, 639; 1999b, 653-4). He noted that strict laws will say
something to the effect that "whenever there is a certain
distribution of forces and matter in a field of a certain size at time
*t*, it will be followed by a certain distribution of forces
and matter in a field of a certain size at time
*t*'" (Davidson 1999d, 639). And he claimed that
both the antecedents and consequents of such laws, when covering
particular mental events and actions, will cover much larger regions
of space than merely the agent or her action. Why? Because while
singular causal statements are *singular*, and therefore select
from a complete set of causal factors those that are salient or in
line with our particular explanatory interests, strict laws
don't themselves select--"that's what makes
them strict" (Davidson 1999d, 640; see Yalowitz 1998a for an
extended discussion of this issue and its bearing on the argument for
both mental anomalism as well as monism). Davidson soft-pedals how
this view bears on the uniqueness claim in the official statement of
Anomalous Monism, parsing away that claim in favor of the blander idea
that "some physical description applies to each mental
event" (Davidson 1999b, 654). As subtle as it seems, this
appears to be a fundamental shift in Davidson's thinking about
monism, though it goes unexplored in his later work and has failed to
attract the attention of his critics.



In any case, Anomalous Monism thus does not inherit the problem of how
to justify specific identifications between mental and physical
events, because the claim that there is a physical description for
each mental event is established purely *a priori*. And the
physical descriptions are not (indeed, cannot be) specifiable in
precise and uniquely identifying spatial and temporal terms. As we are
about to see
 (5.2),
 each of these points is overlooked by many of Davidson's
critics. That the latter is overlooked is understandable, given its
late appearance. However, the former point has always been
fundamental, and critics' failure to appreciate it is
curious.



Davidson additionally claims that the relation between the mental and
physical properties is not merely haphazard or coincidental. A
relationship of supervenience obtains between the two (Davidson 1970,
214; 1973a, 253; 1993; 1995a, 266). (Davidson never argues for
supervenience. For discussion, see the supplement on
 Supervenience and the Explanatory Primacy of the Physical.)
 A working statement of this relationship is that if two events fail
to share a mental property, they will fail to share at least one
physical property (Davidson 1995a, 266)--or, equivalently, if two
events share all of their physical properties, they will share all of
their mental properties. It is meant to articulate a kind of
dependency of the mental on the physical, and correlatively a kind of
explanatory primacy to the physical, but without claiming any kind of
reductive relation between the mental and the physical. The working
statement's truth depends, it seems, on the thought that the
distribution of physical properties somehow *explains* the
distribution of mental properties--failure to share a mental
property *depends upon/is explained by* failure to share at
least one physical property. The supervenience relation is usually
understood to issue in generalizations of the following kind:
'*P*1 - *M*1',
'*P*2 - *M*1',
etc. (where antecedent and consequent occur at the same time). This
allows for the empirical possibility that a number of different
physical state kinds underlie the same mental state kind (for more on
this, see the supplement on
 Related Issues
 (Mental Anomalism and Semantic Externalism)). However, it also
appears to suggest the existence of lawlike relations between physical
and mental properties, and so to be in tension with mental anomalism.
This issue will be explored in
 5.3.


### 5.2 Objections to Token Identity



The token-identity thesis has been the subject of a number of
interesting criticisms. Many of them, however, are difficult to bring
fully into contact with Davidson's own particular version of the
thesis, primarily because Davidson's version is derived *a
priori* from the other premises in his framework. So, for
instance, it has been argued that mental events do not bear the burden
of the spatiotemporal precision of physical events that they would
need to if the former were genuinely identical to the latter (Hornsby
1981; Leder 1985). For example, it would seem arbitrary to identify
the deduction of some conclusion from a chain of reasoning with some
particular neural event or set of neural events occurring at a
specific time and place in the brain--especially given the
micro-precision of the neural framework. Compare attempting to provide
physical description for the action of paying back a debt--how
does one determine the spatial and temporal parameters with the
precision demanded by the language of physics? Distinguishing between
"the" physical event, as opposed to its causes and its
effects, can seem daunting if not outright nonsensical (Leder 1985;
see also di Pinedo 2006). Further, it has been argued that the only
possible empirical evidence for specific token-identity claims could
be type-identities between either those or other mental and physical
properties, because evidence needs to be drawn from variant cases in
order to sort out merely coincident from identical events (Leder
1985).



Such criticisms become difficult to evaluate given Davidson's
*a priori* procedure for establishing the token-identity
thesis. He can respond that we already know, *a priori*, that
any particular mental event must instantiate some physical property if
it causally interacts with any mental or physical event, given the
cause-law and anomalism principles. Questions about how this physical
property, whatever it is, relates to properties currently invoked in
neuroscience come later and are necessarily secondary to this monistic
conclusion. And there is no guarantee (indeed, it is quite unlikely)
that neuroscientific properties currently in vogue are candidates for
strict-law properties. As we have just seen
 (5.1),
 Davidson eventually came to explicitly associate the physical
properties that cover mental events with broad descriptions covering
large space-time regions. Further, it would confuse epistemology with
metaphysics to insist that, because we can only establish which
physical property some mental token event instantiates by leaning on
some type-correlations between other mental and physical properties,
token-identity claims presuppose type-identity. How we discover the
particular physical properties is one thing; whether there can be
psychophysical laws is quite another, and not settled by the method of
discovery.



We also need to keep in mind that Davidson embraces the possibility of
substantive mental-physical correlations (*ceteris paribus*
psychophysical laws), which directly address these epistemological
issues. More generally, Davidson's token-identity claim is that
the predicates that come to form the vocabulary of the as-yet unknown
strict-law science will be capable of being used to describe mental
events. While we cannot judge this claim by appealing to features of
current neuroscience, it also seems that it should be possible to
adjudicate conceivability concerns. And, putting aside
Davidson's later views, while we are not currently in the
business of assigning fine-grained spatiotemporal parameters to mental
events, it does not seem obvious that we couldn't come to accept
such assignments on the basis of theoretical considerations without
thereby committing ourselves to the existence of type-identities.
However, Davidson's official position, early and late, has
always been that we do not need to be capable of making such
assignments in order to assert token-identity--there must simply
be such true assignments, and this is something we know on the basis
of a purely *a priori* argument. (Davidson 1999b; for further
discussion of this issue, see the supplement on
 Related Views
 (Bare Materialism); for a different criticism of token-identity, see
the supplement on
 Related Views
 (Other Positions). For a criticism based upon Davidson's own
treatment of causal explanation, see Horgan and Tye 1985. For
discussion of the criticism that Davidson's monism is too weak
to warrant the label 'materialism', see the supplement on
 Token-Identity and Minimal Materialism).


### 5.3 Is Supervenience Consistent with Mental Anomalism?



We have seen that Davidson supplements his monism with a claim of
supervenience. There are many different conceptions of the
supervenience relation (see Kim 1993b), and Davidson ultimately came
to identify his version with what is called "weak"
supervenience, in contrast to "strong" and
"global" supervenience. Briefly, the basic differences
between these positions are as follows. Weak supervenience links
specific mental and physical properties within but not across possible
worlds, while strong supervenience links those properties across
worlds. Global supervenience links the class of mental properties as a
whole with the class of physical properties as a whole within but not
across worlds, but does not constrain relations between specific pairs
of mental and physical properties. Weak supervenience comes down to
the view that mental properties depend upon those physical properties
they are correlated with within a particular possible world, but those
very same physical properties may, in another possible world,
correlate with very different (or even no) mental properties. Weak
supervenience is thus stronger than global supervenience, in that it
posits correlations between particular pairs of mental and physical
properties, but weaker than strong supervenience in that it recognizes
the possibility that these correlations can fail to obtain in other
possible worlds. (It should be noted that Davidson never brought his
views on supervenience into contact with his later views, noted above,
about the broad nature of the physical properties that mental events
must instantiate according to Anomalous Monism. It is not at all clear
whether or how these views can be combined. In the following
discussion of supervenience, this complication will be ignored, and it
will be assumed that the physical properties in question are not of
this broad nature, since this is how Davidson's own discussions
of supervenience seem to proceed, and certainly what his critics
presuppose.)



The puzzling aspect of Davidson's doctrine of supervenience
arises independently of fine points of the disagreement between the
competing conceptions of supervenience sketched above. Whether the
dependency is between particular mental and physical properties, or
sets of the two, and whether or not the dependency holds only within
or also across possible worlds, it appears that it entails that there
will exist strict laws on the basis of which mental events can be
predicted and explained that were supposed to be ruled out by the
anomalism principle. Davidson sometimes claims (Davidson 1995a, 266)
that supervenience is actually *entailed* by Anomalous Monism,
in which case it would appear to follow that Anomalous Monism itself
is an inconsistent theory--entailing both that there cannot be
any strict psychophysical laws (the anomalism principle) and that
there must be such laws (supervenience). But generally his position
appears to be that Anomalous Monism is simply consistent with
supervenience (Davidson 1993, 7). If supervenience and Anomalous
Monism are indeed inconsistent, and the former is rejected, the
question of the plausibility of a materialist position with no
discernible relation between mental and physical properties arises
(see the supplement on
 Supervenience and the Explanatory Primacy of the Physical).
 (The caveat about the relation between Davidson's later views
about physical descriptions and supervenience noted at the end of
 5.1.
 should be kept in mind here.)



Why does supervenience appear to generate strict laws? When Davidson
first stated the supervenience claim, he articulated it in the
following terms: "there cannot be two events alike in all
physical respects but differing in some mental respects"
(Davidson 1970, 214)). This formulation appears to entail strict
psychophysical laws of the form
'*P*1 - 
*M*1'. Davidson later came to focus on the
inversion of this formulation: "if two events fail to share a
mental property, they will fail to share at least one physical
property" (Davidson 1995a, 266). The advantage of this
reformulation is that it brings out the fact that the requisite
physical differences *need not be the same* in each case of
mental difference (see Davidson 1973a, 253-4). As Davidson says,




> 
> 
> although supervenience entails that any change in a mental property
> *p* of a particular event *e* will be accompanied by a
> change in the physical properties of *e*, it does not entail
> that a change in *p* in other events will be accompanied by an
> identical change in the physical properties of those other events.
> Only the latter entailment would conflict with [Anomalous Monism].
> (Davidson 1993, 7)
> 
> 
> 



There seem to be two problems here, however. First, the inverted
reformulation actually entails the original thesis--that if two
events share all physical properties they will share all mental
properties--and so once again generates strict psychophysical
laws. Second, even if the accompanied physical changes can be
different, that simply generates *more* strict psychophysical
laws--'
*P*1 - *M*1',
'*P*2 - *M*1',
and so on. So it is hard to see why Davidson thinks that the second
formulation is consistent with the anomalism principle.



Some defenders of Davidson (Child 1992, 224; see also Davidson 1973,
258) have responded to the apparent tension between supervenience and
mental anomalism by emphasizing that the degree of detail that would
have to go into the formulation of such laws would make them useless
for prediction, since it is unlikely that the relevant initial
conditions will repeat. But as we have seen
 (4.2.3),
 this seems to be true of any candidate for a strict law--it must
take into account all possible interfering conditions, and doing so
becomes quite unwieldy for generating predictions. And in any case,
such laws would still provide strict *explanations* of mental
events, contrary to Davidson's own formulation of mental
anomalism. So the problem that supervenience 'laws' seem
to pose for the anomalism principle remains.



Other defenders of Davidson (see Macdonalds 1986) have responded to
this problem by arguing that the existence of strict supervenience
laws is compatible with mental anomalism so long as we are not
actually able to state any such laws and thus be in a position to use
them to predict and explain actual mental events--which is
certainly the case currently and likely for the foreseeable future.
This suggestion exploits a literal reading of Davidson's
official statement of the anomalism principle, which denies the
possibility of strict laws on the basis of which mental events *can
be explained or predicted*. But in doing so, it makes Anomalous
Monism into a much weaker position, dependent on the cognitive
limitations of human beings. It in effect becomes a contingent
epistemological position rather than the necessary metaphysical
doctrine it purports to be.



Davidson in one place offers a very different suggestion in response
to the problem. He claims that the supervenient relations between
mental and physical predicates that he envisages are of a *ceteris
paribus* nature. He accepts the requirement that any satisfactory
account of the relation between mental and physical properties must
permit appeal to local correlations and dependencies between specific
mental and physical properties (Davidson 1993, 9). But he blocks any
entailment from this requirement to strict psychophysical laws,
suggesting that such 'correlations' and
'dependencies' are of a *ceteris paribus* form.



Such a *ceteris paribus* conception of supervenience has not
been discussed in the extensive literature on the topic (its
possibility is recognized and endorsed by Kim 1995, 136; however, see
Kim 1993, 24-25) and it is unclear whether it can deliver a
suitably strong notion of dependency to satisfy materialist
intuitions. But it does seem to be an attractive way of reconciling
supervenience with mental anomalism so that Anomalous Monism remains a
consistent theory.


## 6. The Epiphenomenalism Objections



It has been widely held that Anomalous Monism cannot avoid
epiphenomenalism--the view that mental events lack
causal/explanatory powers. At a first approximation, the concern
derives from a tension between mental anomalism and the apparently
privileged status assigned to physical properties in Davidson's
framework--in particular, that all events are physical, and all
physical events have a strict explanation in terms of other physical
events. It then becomes an important question what sort of
causal/explanatory role mental properties can play when all events
already have a physical explanation.



Some welcome this result, holding that mental events explain actions
in a *sui generis* way not accountable for in the terms of
typical scientific explanations (see von Wright 1971; Stoutland 1976;
Wilson 1985; Ginet 1995; Campbell 1998 and 2005 and related discussion
in the supplement on
 Explanatory Epiphenomenalism).
 Many, however, see this charge as devastating to the prospects of
Anomalous Monism's attempt to occupy a position between
reductionist materialism and dualism. Without a distinctive causal
role for mental events to play in the explanation of action, many
think that they would lack the sort of robust reality needed to
compete with reductionism and dualism. On this way of thinking, only
causal powers can justify mental realism. So if Anomalous Monism
cannot avoid epiphenomenalism, it appears to open the door to
eliminativist materialism, which holds that mental vocabulary and
explanations are vacuous and ought to be thrown out and replaced by
neuroscience (assuming, which seems extremely doubtful, that
neuroscience can itself supply strict laws--if not, then this
line of thought would lead to throwing out all but
'physical' strict law properties and explanations).



As noted, the epiphenomenalist worry arises from two points that are
absolutely basic to Anomalous Monism--first, that mental events
are at the same time physical events, and, second, that while mental
predicates cannot figure into strict causal laws, physical predicates
must. Early critics moved quickly from these points to the
epiphenomenalist conclusion that mental properties are causally
irrelevant, because there are always strict law
properties--physical properties--to causally explain the
occurrence of an event. (For detailed discussion of this line of
argument, see the supplement on
 Mental Properties and Causal Relevance.)
 Among many other problems with this line of argument, however, there
is the one immediately capitalized on by Davidson: that within the
extensionalist metaphysical framework in which Anomalous Monism is
developed
 (2.1
 above), properties don't cause anything, and so can be neither
causally relevant nor irrelevant. According the Davidson, only events
are causal *relata*. He expresses general skepticism about
epiphenomenalist objections to Anomalous Monism that depend on the
idea that events cause 'by virtue' of the properties they
instantiate (Davidson 1993, 6, 13). This is closely connected to his
sharp distinction between causation--a metaphysical relation
between particular events independently of how they are
described--and explanation--which relates events only as
they are described in particular ways. But as we will now see, this
doesn't end the concerns about epiphenomenalism. (For related
discussion concerning epiphenomenalism and its bearing on the
relationship between Anomalous Monism and human freedom, see 
 Related Issues: 3.2 Anomalous Monism and Contemporary Compatibilism.)


### 6.1 Mental Properties and Explanatory Relevance



Critics of this extensionalist line of defense insisted that related
questions remained about Anomalous Monism even taking into account the
distinction between causation and explanation. In particular, they
questioned whether mental properties could play any genuine
explanatory role--whether they had *explanatory
relevance*--given the priority assigned to physical
properties in Davidson's framework. Why think that mental
properties explain anything given that the events which instantiate
them always also instantiate physical properties that figure in causal
laws? One thought here is that genuine explanations require laws, and
mental anomalism, in ruling out psychological and psychophysical laws,
cannot account for any explanatory role for mental properties vis a
vis physical or mental events.



In response, Davidson notes that while Anomalous Monism rejects the
possibility of strict laws in which mental predicates can figure, it
allows for *ceteris paribus* psychological and psychophysical
laws (Davidson 1993, 9-12). His point appears to be that if
backing by law is sufficient for explanatory relevance, then mental
properties are explanatorily relevant. (Davidson and his critics often
slide between the issues of causal and explanatory relevance, but the
latter issue is clearly what is at stake given Davidson's views
about causal efficacy and properties.) Second, Davidson appeals to the
supervenience of mental properties on physical properties in order to
ground the explanatory role of mental properties. Davidson says
that



> 
> 
> properties are causally efficacious if they make a difference to what
> *individual* events cause, and supervenience ensures that
> mental properties do make a difference to what mental events cause.
> (Davidson 1993, 15)
> 
> 
> 



The first point does not get developed by Davidson in any systematic
way, though it has been explored by others interested in defending
nonreductive monism from epiphenomenalist concerns. Some have focused
on exploiting *ceteris paribus* covering laws for
psychophysical causal relations, claiming that this allows mental
properties to be sufficient for their effects, thus providing the
needed type of explanatory role (McLaughlin 1989; Fodor 1989, 1991).
Others have attempted to sidestep the issue of covering laws entirely
by appealing directly to the truth of psychological and psychophysical
counterfactuals in grounding the explanatory role of mental properties
(LePore and Loewer 1987, 1989; Horgan 1989). Davidson himself instead
focused on supervenience (although as we are about to see, the
possibility of *ceteris paribus* laws enters into his
account).



Supervenience implies that



> 
> 
> if two events differ in their psychological properties, they differ in
> their physical properties (which we assume to be causally
> efficacious). If supervenience holds, psychological properties make a
> difference to the causal relations of an event, for they matter to the
> physical properties, and the physical properties matter to causal
> relations. (Davidson 1993, 14) 
> 
> 
> 



The point here is not simply that mental properties inherit or
piggyback on the causal powers of the physical properties on which
they supervene. Rather, Davidson appears to be claiming that mental
properties *influence* the causal powers of their subvenient
physical properties.



One problem with Davidson's response here is its reversal of the
dependency relationship between mental and physical properties
typically claimed in supervenience relationships. A central rationale
for positing supervenience is to mark a kind of explanatory primacy to
the subvenient properties (see the supplement on
 Supervenience and the Explanatory Primacy of the Physical).
 And this is reflected in the first part of Davidson's
formulation above--surely a difference in psychological
properties entails (requires) a difference in physical properties
*because* the difference in physical properties is needed in
order *to explain* the difference in psychological properties.
So the sense in which psychological properties 'matter' to
physical properties is that changing the former amounts to a change in
the latter *because* a change in the latter explains a change
in the former. This does not appear to be helpful in establishing the
explanatory relevance of mental properties. Another problem, discussed
above
 (5.3),
 is that it is difficult to see how a supervenience relation of
sufficient power to make mental properties explanatory of an
event's physical properties in the way Davidson seems to suggest
does not issue in strict laws. So it is unclear how supervenience is
consistent with the anomalism principle, and thus how it can help
block epiphenomenalist concerns, although we did previously note one
potentially worthwhile but unexplored possibility--a *ceteris
paribus* supervenience relation--which Davidson endorses.


### 6.2 Interest-Relativity and the Dual *Explananda* Strategy



Kim has explored a related but different route from Anomalous Monism
to mental epiphenomenalism--the problem of explanatory exclusion
(Kim 1989, 44). A causal explanation of an event cites a sufficient
condition for that event's occurrence. This seems to exclude the
possibility of other independent causes or explanations of that event.
So if, as Anomalous Monism entails, physics can provide a sufficient
explanation of any particular event, there appears to be no room for
an independent and irreducible mental explanation of an event
(Davidson 1993, 15). It is because the cause instantiated some
particular physical property that the effect (which happens to
instantiate a mental property) came about. Any mental properties that
the cause instantiates seem superfluous in explaining why the effect
occurred--unless those properties are identical or related in
some strict lawlike way to the physical properties, something ruled
out by the anomalism principle.



Davidson responds by arguing that citing only the physical properties
of the cause to provide a sufficient explanation of an action does not
address the particular interests that psychological explanations of
actions serve--providing the reasons of the agent in light of
which she performed the action that she did. Serving these explanatory
interests compensates for the fact that such explanations cannot be
sharpened into strict laws or folded neatly into physical laws
(Davidson 1991, 163). We only understand why the agent *waved her
hand*--why the effect is of the mental kind 'waving
one's hand' (as opposed to merely 'one's hand
going up and down')--by citing *mental* properties
of the causing event, such as her wanting to greet her friend. The
citation of physical properties of the causing event and the
associated mere bodily movement will not bring about such
understanding, assuming mental anomalism, because of the lack of any
reductive relationship between either the physical properties of the
cause and the agent's reasons or the physical properties of the
effect and the agent's action.



Here we see the interest-relativity of explanation and its bearing on
explanatory relevance (see the supplement on
 Mental Properties and Causal Relevance)
 playing an important role for Davidson. Mental properties must be
cited if we want a *rational* explanation of *mental*
effects. Davidson's response to epiphenomenalist concerns can
thus be described as a kind of 'dual *explananda*'
theory of the explanatory role of mental properties. According to this
theory, for every (causally interacting) mental event there are two
distinct *explananda* in need of explanation: an event of a
certain physical type and an event of a certain mental type. Mental
properties are accorded an ineliminable and (given Anomalous Monism)
irreducible explanatory role by virtue of their singular capacity to
make intelligible the occurrence of other mental properties through
the *sui generis* relation of rationalization. This reflects
the point made at the end of
 4.3
 by the causal definition interpretation of the argument for mental
anomalism: that rationality underlies, not mental anomalism, but
rather mental realism. (For related discussion of the dual
*explananda* approach, see Macdonalds 1995 and Gibbons
2006.)



It should be noted, however, that it is not the case that
*only* mental properties can explain and be explained by the
occurrence of mental properties. That would lead to an
"outlet" problem, with mental properties being
explanatorily insulated from physical properties--something
inconsistent with the way in which we ordinarily think of
mental-physical interaction. A blow to the head can, for instance,
explain the occurrence of a thought. And a thought can explain the
movement of an object, as when my decision to quench my thirst leads
to the movement of a glass of water to my lips. However, the blow
cannot rationalize the thought, and the decision cannot rationalize
the movement of the glass (though it can rationalize the
*action* of *moving* the glass). Davidson's dual
*explananda* strategy provides no account of such phenomena
(for discussion of the outlet problem, see Gibbons 2006). Nonetheless,
so long as there are occurrences of mental properties in need of the
distinctive kind of explanation provided by rationalization, mental
properties occupy an ineliminable explanatory role. And given
Anomalous Monism, that role is irreducible. It is worth noting that
this dual *explananda* strategy is consistent with
Davidson's commitment to the causal closure of the physical
domain (Crane 1995 seems to miss this point)--every physical
event can have a physical explanation, even if the mental component of
some physical events can be rationally explained only through appeal
to mental components of the causing event. Therefore, however causal
closure ultimately enters into Anomalous Monism (see the supplement on
 Causal Closure of the Physical and Anomalous Monism),
 it does not appear to create any further problems for Anomalous
Monism's ability to account for the ineliminable, irreducible
explanatory role of mental properties.



The interest-relativity of causal explanation is thus crucial in
Davidson's grounding of the ineliminable explanatory role of
mental properties within the framework of Anomalous Monism. If, as
Anomalous Monism contends, mental event-types such as actions are not
reducible to physical-event types, then the only way to explain
actions (as opposed to mere bodily movements) so as to make them
*intelligible* is by appeal to the mental properties of the
cause--reasons. (For discussion of whether, in light of this,
reason explanations can still be maintained to be *causal*
explanations within the framework of Anomalous Monism, see the
supplement on
 Explanatory Epiphenomenalism.)


### 6.3 The Causal Constitution of Reasons



A final point to consider in evaluating the epiphenomenalist
objections to Anomalous Monism is the way in which causality enters
into the constitution of reasons and reasons-explanations according to
Davidson. Before we have established the anomalism principle, or go on
to derive monism, we already know that reasons explain actions by
causing them (the 'because' problem discussed in
 2.2).
 And, as we have seen
 (4.3),
 we know that propositional attitudes and mental contents are
individuated, and thus defined, partially in terms of what they are
caused by and cause (for attitudes, see Davidson 1987b, 41; for
contents, see Davidson 1987a, 444, and extended discussion in the
supplement on
 Related Issues
 (Mental Anomalism and Semantic Externalism)). But if something cannot
even be recognized as a reason unless it is a cause, then the charge
that mental properties are causally impotent appears to have
difficulty getting any traction. And since these claims are prior to
the argument for monism, they are neutral about whatever else reasons
must be in order to be causes. So reasons must be recognized as causes
prior to any discovery that they are also physical events. This
appears to secure the causal potency of reasons in a way entirely
independent of the claim of token-identity. Within Davidson's
framework, reasons can only play the rationalizing and explanatory
role that they do by virtue of their causal nature.



Many of Anomalous Monism's epiphenomenalist critics do not
address this rich causal background. As we have seen, the background
is not sufficient by itself to silence all epiphenomenalist concerns.
But it does significantly affect how those concerns can be formulated
and addressed. Anomalous Monism is clearly deeply committed, at a
number of levels, to the causal explanatory relevance of the mental,
and so charity suggests that we try to understood it in a way such
that these commitments are respected. The dual *explananda*
strategy discussed above
 (6.2)
 provides one promising framework for doing this, while at the same
time displaying sensitivity to the sorts of concerns driving the
epiphenomenalist objections.


## 7. Conclusion



Despite the initial appearance of simplicity in its assumptions,
structure and argumentation, we have turned up several important
problems and lacunae that stand in the way of any overall final
assessment of the plausibility of Anomalous Monism. While the central
objections it has faced have derived from epiphenomenalist concerns,
the force of these objections is not clear. Arguably, the most serious
difficulties for Anomalous Monism are not with its adequacy but with
its justification. We still stand in need of a clear argument for how
rationality leads to the anomalism principle; there are the
substantial problems surrounding the status of the causal closure of
the physical and its bearing on monism; and the cause-law
principle's strictness requirement is still in need of a
compelling rationale. Even with these problems, Anomalous Monism
continues to provide an extremely useful framework for exploring
fundamental issues and problems in the philosophy of mind, and has
earned a central place on the rather short list of important positions
on the relation between mental and physical events and properties.