## 1. Preliminaries


### 1.1 *A Priori* Knowledge and Justification: The Standard View



The concept of the *a priori* is fundamentally a concept of
*independence from experience*. The *a priori* stands in
contrast to the *a posteriori* or empirical. Knowledge is
empirical just in case it is derived from experience. What experience
includes is contested. Experience uncontroversially includes sense
perception. It arguably also includes introspection and the testimony
of others. Much of what we know is empirical: we know by sense
perception or introspection or the testimony of others, etc. *A
priori* knowledge--if there is any--would be independent
of sense perception, introspection, etc. (see entry on
 rationalism vs. empiricism).
 A majority of epistemologists could probably agree that justification
is necessary for knowledge if one interprets justification broadly
(e.g., so that a belief might be justified in virtue of being produced
by a reliable cognitive mechanism, or by an exercise of intellectual
virtue, or by having supporting evidence from good reasons). For the
purposes of this entry, we will understand justification broadly and
assume that in order to have *a priori* knowledge of a
proposition one's belief in that proposition must be justified
(see entries on
 the analysis of knowledge;
 foundationalist theories of epistemic justification;
 coherentist theories of epistemic justification;
 internalist vs. externalist conceptions of epistemic justification).



So on what we will call the standard view of *a priori*
knowledge and
 justification,[1]
 being justified makes a very significant contribution to the
epistemic status required for knowledge. Hence, for one's
knowledge to be independent of experience, one's justification
would also have to be independent of experience. Such justification is
*a priori*.



However, it is unlikely *S* could be justified in believing any
proposition *P* in a way that is completely independent of
experience. For one thing, *S* must grasp or understand *P*
before *S* could be justified in believing it. According to one
familiar view, propositions involve properties and in order to
understand a proposition, *S* must have or grasp concepts
corresponding to these properties. The majority of our concepts are
empirical. Hence, without experience *S* could not believe, or
even understand, most propositions; so without experience *S*
could not be justified in believing these propositions. For example,
it is unlikely the concepts of marriage and bachelorhood are innate,
so not even
 (1)
 is a proposition *S* could be justified in believing without any
experience at all. Hence, the sense in which *a priori*
justification is independent of experience must be further specified:
at the very least, experiences required to understand a proposition,
including experiences necessary to grasp the relevant concepts, do not
count against being justified independently of experience.



According to the standard view of *a priori* justification,
once *S* has the experiences needed to acquire the concepts of
marriage and bachelorhood and *S* understands
 (1),
 *S* has justification to believe
 (1).
 No additional experience is needed. Compare:



(7)
 that all bachelors are untidy.


If *S* has the experiences needed to acquire the concepts of
bachelorhood and untidiness, acquires these concepts, and understands
(7), *S* will not have a justification to believe (7)--even
if we suppose, for the moment, that all bachelors are untidy. *S*
would have to observe many bachelors and their personal habits, or be
told about the personal habits of bachelors by others for (7) to be
justified. As we've already noted,
 (1)
 is different: once *S* understands
 (1),
 this proposition will be justified for *S*--or so says the
standard view.



So far we have only a negative account of *a priori*
justification; it is justification that does not depend on experiences
beyond those necessary for understanding. But in virtue of what could
*S* be justified in believing something apart from experience?
The standard answer appeals to the special nature of the propositions
that can be *a priori* justified: they are supposed to be
self-evident.



(SE)
A proposition *P* is self-evident just in case *P* is
evident for any person *S* who understands *P*. (*P* is
evident for *S* when *S* has a degree of justification
for *P* that, when combined with some other conditions, is
sufficient for *S* to have knowledge of *P*.)


This definition of self-evidence may not be entirely satisfactory. One
seeking a positive, informative account of how *S* could be
justified in believing *P* simply in virtue of the fact that
*S* understands *P* should not be satisfied when told that
*P* is a special, self-evident proposition, when all this means
is that *P* is justified to a high degree *for everyone who
understands it*. Nevertheless, the lack of an explanation of the
mechanism that brings something about is not a decisive reason for
thinking it could not come about. We shall assume that (SE) correctly
defines self-evidence.



Even though any person, *S*, who understands a self-evident
proposition, *P*SE, will be justified in believing
*P*SE to a degree sufficient for knowledge, we cannot
say that if *S* understands *P*SE and believes
*P*SE, then *S* will know *P*SE.
We have not yet addressed the connection between self-evidence and
truth, but this is not the problem: self-evidence is taken to imply
truth. To explain why *S* could understand and believe
*P*SE but fail to know *P*SE, it will
be helpful to distinguish between propositional justification and
doxastic justification.



We introduce the distinction in terms of having good reasons, but it
can be generalized to other ways of being justified. If *S* has
good reasons for believing a proposition, *P*, e.g., if *S*
knows some propositions that straightforwardly entail *P*,
*S* has a propositional justification for *P*. Note that
*P* might be propositionally justified for *S* even though
*S* does not believe *P*--while *S* knows
propositions that entail *P*, the proposition *P* might
never have even occurred to *S*. E.g., suppose *S* knows
that her only pets are two cats. This entails that she has no pet
hippopotamus, so this proposition is propositionally justified for
*S*. But unless *S* is a little odd, this is not a
proposition *S* currently believes. The formulation
"*P* is propositionally justified for *S*"
leaves open whether *S* believes *P*. The formulation
"*S* is propositionally justified in believing
*P*" indicates that *P* is propositionally justified
for *S* and that *S* believes *P*.



If *S* believes *P* and does so *on the basis of good
reasons*, then *S*'s believing *P* is doxastically
justified. Significantly, doxastic justification requires more than
propositional justification plus belief. *P* could be
propositionally justified for *S* and *S* could believe
*P*, but not believe *P* on the basis of the good reasons
that constitute *S*'s propositional justification for
*P*. E.g., despite having excellent reasons to believe there are
no vampires, Vlad believes he is safe from vampires only because he
eats lots of garlic and wears a special cross to repel vampires.
Vlad's belief that he is safe from vampires would be
propositionally justified, but not doxastically justified. Unless
noted, when we use "justified" and its cognates without
qualification we will mean "doxastically justified".
Knowledge requires basing the belief in the proposition on something
that justifies it. This goes for moral knowledge of self-evident moral
propositions as well as it goes for any other kind of knowledge.



So far, the standard view may understand the class of *a
priori* propositions too narrowly. Mathematics and logic are
regarded as the paradigm *a priori* disciplines. But it is
doubtful that all the mathematical and logical truths we know are
self-evident. Many of these truths require proof. When *S*
believes such a proposition, *S*'s belief will not be based
solely on understanding the proposition. *S*'s experience
of constructing the proof will play an important role in
*S*'s justification for believing the proposition proven.
If the proof is complex, *S*'s justification will probably
in part rely on memory, e.g., of lemmas proven along the way. The
standard view can extend the class of *a priori* propositions
without compromising its basic approach by adding that if *S*
believes *P* on the basis of proving it from self-evident
premises by steps that are self-evidently valid, then *S* is
*a priori* justified in believing *P*.



To sum up, the standard view holds that *a priori* knowledge is
justified independently of experience, where this means experience
beyond the experience required to understand the relevant proposition.
There are certain special, self-evident propositions that are
propositionally justified for any person who understands them. If a
person believes a self-evident proposition solely on the basis of
understanding it, the person will be doxastically justified in
believing it. Such propositions are often referred to as *a
priori*, which should be taken to mean that it is possible for one
to be *a priori* justified in believing them. By extension,
propositions are also *a priori* if they can be deduced from
self-evident premises via steps that are self-evidently valid. A
person who believes such a proposition on the basis of such a proof
will be *a priori* justified in believing it. It is also
possible to be empirically justified in believing an *a priori*
proposition, but one cannot be *a priori* justified in
believing empirical
 propositions.[2]



Before closing the presentation of the standard view, we should
highlight a potential problem already implicit in our presentation. As
we stressed, the basic concept of *a priori* justification is
of justification that is independent of experience. The standard view
recognizes that one typically needs experience to understand a
proposition, and interprets experience independent justification as
justification that requires no additional experience. But consider an
experience like this. You believe a mathematical proposition is true,
but solely on a teacher's testimony. You do not know for
yourself. But then after turning the proposition over in your mind for
a while, perhaps by thinking through some examples, you "get
it"; you "see" that the proposition is indeed true
(see Bealer 2000).



What happens in such cases? Understanding alone does not seem to
justify you in believing. To be justified in believing the
proposition--in a way that does not depend upon
testimony--you need to "see" it for yourself. Such
"seeing" has various names, e.g., "intuition",
"rational insight", "clear and distinct
perception". But whatever it is called, it is hard to deny it is
an experience. So the standard view faces a problem: there is a
distinctive kind of experience apparently required for *a
priori* justification in believing, and hence, *a priori*
knowledge of, some propositions typically regarded as *a
priori* and perhaps even self-evident. One might be led to
question whether one who understands such a proposition but has not
yet had the experience of "seeing" the proposition to be
true even has propositional justification. Finally, one might be led
to wonder whether this kind of "experience" is always
required for *a priori* knowledge and justification that does
not depend upon proof.



Those who take the standard view might respond by accepting that
rational intuition is an experience and distinguishing this experience
from the experiences that are involved in empirical justification,
i.e., perception, proprioception, introspection, and memory. This
modified standard view could then maintain that *a priori*
knowledge and justification are independent of the latter experiences,
but not necessarily all experience; *a priori* justification
can be grounded in an experience of rational intuition--perhaps
it is always so grounded. Thus, on the modified standard view, the
special role of understanding comes down to this: understanding an
*a priori* proposition is the only *prerequisite* for
rational insight into its truth; understanding the proposition does
not guarantee that one will attain such insight, but it is the only
thing that is necessary. Notice, on this modified standard view,
self-evident propositions no longer play such a prominent role. It is
not an essential part of the view that there are special propositions,
and anyone who understands one of these propositions has propositional
justification. If one wants to think in terms of special propositions,
there will be propositions that are special only in an attenuated
sense: it is possible for a person to have the experience of seeing
the propositions to be true simply by understanding and thinking about
them. Some might consider this modification too much of a departure
from the spirit of the standard view.



While it is not beyond criticism, we will proceed assuming the
standard view about *a priori* knowledge and justification is
true.


### 1.2 Analyticity and the *A Priori*



According to Kant's original formulation, in analytic judgments
the concept of the predicate is contained in the concept of the
subject (1781 [1998]: A6-7).
 (1),
 that all bachelors are unmarried, provides a good illustration. On
one view, being a bachelor is a complex concept that is composed of
being unmarried as well as being an adult male. So the concept of a
bachelor "contains" the concept of being unmarried. Hence,
part of thinking of someone as a bachelor is thinking of him as
unmarried. Compare this with the synthetic proposition
 (7),
 that all bachelors are untidy. The concept of being a bachelor is not
partly composed of the concept of being untidy. Thinking of someone as
untidy is not part of thinking of him as a bachelor. So being a
bachelor does not "contain" being untidy. A more
contemporary understanding holds that sentences are analytic just in
case they can be converted into logical truths by replacing terms with
terms that have equivalent meanings (Frege 1884 [1980]). The more
contemporary understanding counts more propositions as analytic than
Kant's original formulation: for example, all logical truths
will be counted as analytic, as well as a sentence such as "if
there is blizzard, then there will be snow."



One might be tempted to think that all and only propositions expressed
by analytic sentences can have *a priori* justification, and
that propositions expressed by synthetic sentences can only have *a
posteriori* justification. We should resist this temptation. A
number of philosophers, beginning with Kant, have claimed that some
synthetic propositions can have *a priori* justification. As we
will discuss below, Kant thought that all moral propositions were
synthetic but could be established only by reason. Moreover, if one
considers what is fundamental to the two distinctions, there is no
obvious reason to assume they would perfectly coincide. The
analytic/synthetic distinction fundamentally concerns conceptual or
meaning relations, specifically, whether the subject of a proposition
contains the predicate or whether the proposition is equivalent to a
logical truth. The *a priori*/*a posteriori* distinction
is fundamentally epistemic, being concerned with whether experience is
required for justification. Two such fundamentally different
distinctions could coincide, but it is not immediately apparent that
they do; it would take considerable work to show that they do.



Finally, we must at least mention Quine's (1951) important
attack on the coherence of the analytic/synthetic distinction. He
argued that there's no clear way of distinguishing between
analytic sentences and sentences that merely express very strongly
accepted propositions. Many philosophers have found Quine's
argument persuasive, but the concept of analyticity has not been
abandoned by all philosophers, indeed a majority still accept it (see
entry on
 the analytic/synthetic distinction).
 We will make use of the of the analytic/synthetic distinction in this
entry.


### 1.3 Cognitivism and Non-Cognitivism



We can divide metaethical positions into two kinds: cognitivist and
non-cognitivist. Cognitivists hold that moral
statements--statements such as "Lying is wrong" and
"Courage is a virtue"--have truth-values, being
either true or false. Cognitivists maintain that when one sincerely
makes a moral statement in an ordinary context, one believes the
proposition expressed by the statement. Non-cognitivists hold that
moral statements are not truth-evaluable: moral statements are neither
true nor false, being more akin to utterances such as (a)
"Haggis, YUCK!" or (b) "Take the haggis away!"
Just as, when one sincerely utters (a) or (b), one does not express a
belief, but does something else, non-cognitivists maintain that one
does something other than express a belief when one makes a moral
statement. The early non-cognitivists A.J. Ayer (1936) and R.M. Hare
(1952) maintained that moral statements were akin to utterances (a)
and (b) respectively, that is, they express either emotive reactions
or commands. Other forms of non-cognitivism propose different accounts
of exactly what one does when one makes a moral statement (see entry
on
 moral cognitivism vs. non-cognitivism).
 Since non-cognitivism holds that we do not express beliefs when we
make moral statements, there is no reason for non-cognitivists to
think that there are any moral beliefs--according to
non-cognitivism, even though moral statements typically have the form
of declarative sentences, there are no moral propositions that
correspond to them. If there are no moral beliefs or propositions,
there is no *a priori* moral justification or *a priori*
moral knowledge. So, the question of whether some moral propositions
can be justified *a priori* really comes up only in the context
of cognitivism.



However, many non-cognitivists want to vindicate as much of actual
moral thought and practice as possible, particularly quasi-realists
such as Simon Blackburn (1993) and Alan Gibbard (2003). While denying
that there are, strictly speaking, moral propositions that are true or
false (or moral beliefs, or moral arguments that are valid or
invalid), they would at the same time maintain that in the moral realm
there are things close enough to propositions, truth, belief, and
validity that our practice of speaking of such things as moral beliefs
and these beliefs being true or false makes sense. And such theorists
would certainly want to allow that moral beliefs can be better or
worse in a way that closely corresponds to beliefs being more or less
epistemically justified, strictly understood. So there are interesting
questions about whether there is something closely akin to *a
priori* moral justification (and knowledge) on these views. But in
this entry we will limit ourselves to cognitivist theories.



Moreover, serious questions regarding *a priori* moral
knowledge and justification arise only for non-error-theoretic
versions of cognitivism. Error theories, such as J.L. Mackie's,
hold that moral statements express propositions, and hence are true or
false, but that these propositions are all false. Moral propositions
are systematically false because they presuppose something radically
mistaken. Mackie claims they presuppose the existence of objectively
prescriptive moral facts, when there are no such facts (1977: Ch. 1;
but see Berker 2019, which contests the standard interpretation of
Mackie presented here). A person could be justified in believing a
false proposition, but one could not know it. And it is difficult to
see how one could even be justified *a priori* in believing a
proposition of a type that is systematically false because it makes a
radically mistaken presupposition. Thus, this entry focuses on
non-error-theoretic versions of cognitivism.



Having discussed some metaethical theories such as cognitivism and
non-cognitivism, we should pause to distinguish claims regarding *a
priori* knowledge or justification of moral evaluations from
claims regarding *a priori* knowledge or justification of
meta-ethical propositions, such as that moral statements do not
express propositions. Much meta-ethical theorizing is presented as an
analysis of moral language, and it seems likely that those involved
think of themselves as conducting an *a priori* inquiry. It
would be interesting to devote more specific attention to *a
priori* *meta-ethical* epistemology, but we are concerned
mostly with *a priori* knowledge or justification of moral
propositions.



We focus almost exclusively on moral theories from the 20th
century and later; the exception is Kant, with whom we begin. After
briefly discussing Kant, we move on to the non-naturalist moral
theories presented in the early part of the 20th century by
Moore and Ross. We then consider naturalist moral theories developed
much later in the 20th century, and close by considering
particularism and more recent versions of intuitionism that are
descendants of the positions developed by Moore and Ross.


## 2. Kant's Synthetic *A Priori* Moral Truths



For Kant, there is a close connection between the nature of moral
truths--in particular, their prescriptive content (i.e., what
they direct one to do), as well as their necessity and
universality--and the way in which we discover those truths,
namely, *a priori*. In his view, one can discover a maximally
general, fundamental moral principle. This is a principle that he
calls "the categorical imperative". Kant holds it can be
known through reason alone, specifically, via a transcendental
argument (see entries on
 Kant's moral philosophy
 and
 transcendental arguments).
 He held that we could then deduce more specific, but still general
moral truths from this fundamental principle. Kant provides various
formulations of the categorical imperative, the first being that one
ought to act only in accordance with a
 maxim[3]
 that one can at the same time will to become a universal
law--roughly, an act ought to be done by someone only if the
person could will, without contradiction, that everyone act as he or
she is acting. Examples of more specific principles he deduces from
the categorical imperative are that one ought not make lying promises
or commit suicide. Kant's discussion of lying promises nicely
illustrates how the categorical imperative works: A person in some
difficulty is considering making a promise he knows he cannot keep to
escape the difficulty. To apply the categorical imperative, the person
must consider what would happen if everyone in some difficulty made a
lying promise to escape. If so many lying promises were made, no one
would believe a person who promised to do something, so under these
conditions one could not escape a difficulty by making a promise.
Hence, the person could not consistently will that his maxim be a
universal law, since making it a universal law would frustrate his aim
in making the lying promise. Therefore, one ought not escape a
difficulty by making a lying promise.



In Book II of the Groundwork (1785 [1996]) Kant claims the fundamental
moral truths are synthetic *a priori* because moral truths are
prescriptive. Kant held that the categorical imperative is not
analytic, because although Kant thought the applicability of the
categorical imperative to any given individual is deducible from the
assumption that the individual is rational, the concept of the
categorical imperative is not contained in the concept of a rational
being. Kant thought the categorical imperative must be discovered
*a priori*--through reason--because, as a fundamental
moral law applying to all rational beings, it cannot be discovered
through mere experience: one cannot learn how one *should* act
from how people *do* act.



Moreover, we can see why Kant may have thought that the necessity and
universality of moral truths makes them impossible to discover *a
posteriori*. Regarding necessity: observing how things actually go
seems insufficient to find out how they must go. And regarding
universality: if moral truths are universal in the sense that they are
true in all contexts, then one could only verify the truth of a moral
claim by (a) experiencing all contexts and (b) perceiving the moral
truth in each one. But that is clearly impossible.



Thus, on a standard reading of Book II, the prescriptive content of
moral claims, along with their necessity and universality, led Kant to
believe we know moral truths *only* *a priori*. However,
some interpret Kant as saying that if a moral truth is *a
priori*, then it must also be necessary and universal (Dancy 2007:
45). On this interpretation, if one knows *P* *a priori*,
then *P* must be necessary; after all, it's unclear how one
could know a contingent truth without experience. Moreover, if
*P* is necessary, then *P* must also be universal; for if
*P* must be true, then it is true in every actual case. So, on
this interpretation, Kant's views about moral epistemology
motivate his views about the content of moral claims, not *vice
versa*. Regardless of which interpretation is correct, it's
clear Kant thought there is a close relationship between the content
of moral claims and how we come to know them.



As we will see, moral particularists deny there is any such
relationship between the content of moral claims and the means by
which we know them. Particularists claim that we can have *a
priori* moral knowledge, even though all moral truths are
contingent and particular.



How, specifically, does Kant think that one can establish the
categorical imperative *a priori*? The crucial premise is that
practically rational beings are autonomous, in the sense that their
wills can be determined by rules they give themselves. Kant holds that
the law that an autonomous agent gives to herself must tell her
*which ends to pursue* and not merely *which means to
employ* in light of the ends the agent already has. Kant therefore
rejects the more orthodox conception of practical reason as purely
instrumental, i.e., limited to discovering the means to ends dictated
by something else, e.g., desire. The question then becomes,
"What rule or law could determine the rational will apart from
any end?" that is, "What rule could possibly tell a
rational agent which ends to pursue?" Such a rule would have to
be formal, since it could not simply tell the agent what to do in
light of the ends she already has, and thus could not include any
specification of an end. This leads Kant to the categorical
imperative, roughly: for an agent to perform a moral action, the maxim
the agent acts on must be one that the agent can consistently will to
govern everyone, regardless of their goals, as a necessary law.


## 3. *A Priori* Justification and Early 20th Century Non-Naturalism


### 3.1 The Naturalistic Fallacy and Intuitionism



G.E. Moore reacted against views that provided naturalistic
definitions of moral concepts, especially that of *goodness*
(see entries on
 naturalism,
 and
 moral naturalism).
 One might question whether his targets actually held the view he
criticized, but let's set such worries aside and assume that as
the 19th-century drew to a close, philosophical ethics was
dominated by hedonists who defined "good" in terms of
pleasure, evolutionary ethicists who defined "good" as the
most evolved, utilitarians who defined "right" as what
produces the most utility, and other naturalists. According to such
views, fundamental moral principles are analytic, and hence knowable
*a priori*. Since the fundamental principles defined moral
concepts in natural terms, one can infer whether some specific thing
is good or action right from the principle conjoined with appropriate
propositions about the natural properties of the thing or action, the
latter being knowable empirically. For example, one could infer that
listening to music is good from the analysis of "good" as
conducive to pleasure and the fact that listening to music is often
pleasant. In presenting Moore's response to such naturalistic
definitions, we will focus on the position he took in *Principia
Ethica* (1903 [2003]) (although his views changed significantly
over time).



According Moore, all naturalistic analytic definitions of
"good" fail, committing what he called "the
naturalistic fallacy". To show all naturalistic analyses of
goodness fail, Moore presented the "open-question
argument". The basic idea is that if a definition of
"good" is correct, a morally competent person could not
sensibly question whether something satisfying the definition is good.
Consider a definable term: a triangle is a closed plane figure with
three angles. No person who understands the term can sensibly ask,
"*X* is a triangle, but is *X* three-angled?"
The question is *closed*; an *open* question is one it
makes sense to ask. Moore claimed that for any naturalistic definition
*N* of "good", the question "*X* is
*N*, but is it good?" is open. For example, suppose someone
analyzes "good" as conducive to pleasure. If the analysis
were correct, the question "*X* is conducive to pleasure,
but is it good?" should be closed. But the question is open; it
is perfectly reasonable. One might, e.g., think of
*schadenfreude*--pleasure at another's
misfortune--and wonder whether such pleasure is good. Hence,
Moore would conclude, the analysis fails. Moore held that the argument
can be repeated for any proposed naturalistic analysis of
"good", so "good" cannot be analyzed in
natural terms. He concluded that goodness is non-natural (see entry on
 moral non-naturalism).
 Moore went further, holding that "good" was unanalyzable,
and that the property of goodness was simple and irreducible. These
claims about goodness do not follow from the failure of all
*naturalistic* analyses of "good", since it might
be possible to give a *non-natural* definition of
"good", e.g., as what God approves. However, although he
does not seem to have recognized it, at least in *Principia
Ethica*, the open question argument seems to work against nearly
any definition of "good" just as it works against natural
 definitions.[4]
 (For more on the open question argument and objections to it, see the
entry on
 Moore's Moral Philosophy.)



Because of his views regarding moral concepts and properties, Moore
concluded that the fundamental moral principles are self-evident and
that moral knowledge can come only from moral "intuition".
Superficially, his view seems to comport well with the standard
conception of *a priori* knowledge. But consider how he
explains his position, quoted here at some length:



> 
> 
> [T]he fundamental principles of Ethics must be self-evident. But I am
> anxious that this expression should not be misunderstood. The
> expression "self-evident" means properly that the
> proposition so called is evident or true, *by itself* alone;
> that it is not an inference from some proposition other than
> *itself*. The expression does not mean that the proposition is
> true, because it is evident to you or me or all mankind, because in
> other words it appears to us to be true. That a proposition appears to
> be true can never be a valid argument that true it really is. By
> saying that a proposition is self-evident, we mean emphatically that
> its appearing so to us, is *not* the reason why it is true: for
> we mean that it has absolutely no reason. It would not be a
> self-evident proposition, if we could say of it: I cannot think
> otherwise and therefore it is true. For then its evidence or proof
> would not lie in itself, but in something else, namely our conviction
> of it. That it appears true to us may indeed be the *cause* of
> our asserting it, or the reason why we think and say that it is true:
> but a reason in this sense is something utterly different from a
> logical reason, or reason why something is true. Moreover, it is
> obviously not a reason of the same thing. The *evidence* of a
> proposition to us is only a reason for *our holding it* to be
> true; whereas a logical reason, or reason in the sense in which
> self-evident propositions have no reason, is a reason why *the
> proposition itself* must be true, not why we hold it so to be.
> Again, that a proposition is evident to us may not only be the
> *reason* why we do think or affirm it, it may even be a reason
> why we ought to think it or affirm it. But a reason, in this sense
> too, is not a logical reason for the truth of the proposition, though
> it is a logical reason for the rightness of holding the
> proposition.... When, therefore, I talk of Intuitionistic
> Hedonism, I must not be understood to imply that my denial that
> "Pleasure is the only good" is *based* on my
> Intuition of its falsehood. My Intuition of its falsehood is indeed
> *my* reason for *holding* and declaring it untrue; it is
> indeed the only valid reason for so doing. But that is just because
> there is *no* logical reason for it; because there is no proper
> evidence or reason of its falsehood except for itself alone. It is
> untrue, because it is untrue, and there is no other reason: but I
> *declare* it untrue, because its untruth is evident to me, and
> I hold that that is a sufficient reason for my assertion. We must not
> therefore look on Intuition, as if it were an alternative to
> reasoning. Nothing whatever can take the place of *reasons* for
> the truth of any proposition: intuition can only furnish a reason for
> *holding* any proposition to be true: this however it must do
> when any proposition is self-evident, when, in fact, there are no
> reasons which prove its truth. (1903 [2003]: 143-144)
> 
> 
> 



Note first that Moore's conception of self-evidence is of
propositions whose truth does not depend on anything else; these would
be propositions that express a sort of brute fact. Nothing obviously
follows about the epistemic status of such propositions or about
beliefs in such propositions. In this respect, Moore's
conception of self-evidence differs from the standard conception.
Second, given his conception of self-evidence, Moore chooses an odd
example of a self-evident proposition. For that pleasure is not the
only good seems to *follow* from various propositions regarding
what things are good, propositions that Moore accepted--and that
are apparently self-evident--e.g., that appreciation of beauty is
good.



Finally, to interpret Moore as holding that we are *a priori*
justified in accepting fundamental moral principles, one must adopt
the modified standard view. And his position nicely illustrates the
problem that forces the modification of the standard view. Moore held
that what justifies one in believing a fundamental moral principle is
that the principle is self-evident and that it appears to be true,
i.e., that one has an intuition of it. But this intuition, as an
appearance of truth, is clearly a kind of experience, so it seems that
one's justification for an intuitive belief in a fundamental
moral principle will not be independent of experience. Hence, to
regard this justification as *a priori*, one must make an
exception for this specific kind of experience. While Moore famously
denied hedonism, this was because he denied that pleasure is the only
good. He accepted that pleasure is good, and this proposition nicely
illustrates the tension inherent in the modified standard view of
*a priori* justification, and indeed the standard view, as well
as Moore's *a priori* moral epistemology. Presumably one
must experience pleasure to acquire the concept of pleasure. But then
how exactly is it that one is justified in believing that pleasure is
good? Is it that once one has the concepts of pleasure and goodness,
one believes that pleasure is good simply on the basis of
understanding this proposition? Or is it that once one understands
this proposition, one has a rational intuition of its truth? Or is it
instead that when one experiences pleasure one also experiences its
goodness? If something like the latter, the justification for our
belief that pleasure is good seems more empirical than *a
priori*.



Contrasting Moore's view with Kant's might be helpful.
Kant viewed moral knowledge as fundamentally *a priori* in the
sense that moral knowledge must be the result of careful reasoning
(first transcendental, then deductive); one could discover through
reason the fundamental moral principle, and then deduce from that
principle more specific moral duties. Moore, on the other hand,
explicitly rules out reasoning to fundamental moral principles; since
these principles are self-evident, Moore denies that there are,
properly speaking, any reasons for them. Thus, we find in Moore a
distinctively intuitionist account of *a priori* knowledge, as
opposed to Kant's rationalist account. Moore's account is
intuitionistic because the reason why we believe, and ought to
believe, fundamental moral principles is that they are self-evident
propositions *that appear true to us*.



Moore did not hold that all moral knowledge is intuitive. In the
*Principia* he maintained that the utilitarian principle was
analytic, hence, knowledge of this principle would not require a
special intuition. But he later acknowledged that one cannot define
"right", because the open question argument can be used
against definitions of "right", including the utilitarian
definition. ("This action produces the most good consequences,
but is it right?" is an open question. Corresponding open
questions count against efforts to define "ought", e.g.,
"This action produces the most good consequences, but ought I do
it?") So Moore was driven to hold that the utilitarian principle
was synthetic, and known *a priori* via intuition (Moore 1912).
*However*, since Moore held that one ought to do what produces
the most good, one would have to engage in empirical investigation of
the consequences of various types of action to determine what one is
obligated to do. So on Moore's view, one would not simply intuit
that one ought to keep promises or ought not to kill.



A more interesting reason why Moore did not hold that all moral
knowledge results from direct intuition was that he denied that
intuition is infallible. On his view, it can appear to one that a
false moral proposition is self-evidently
 true.[5]
 Thus, according to Moore, it is possible for the moral propositions
one intuits to conflict. One resolves any conflicts among the moral
principles one intuits--e.g., regarding which sorts of things are
good--by considerations of coherence, with some intuitions
regarding what is and is not good being rejected precisely because of
their conflicts with other intuitions. So while *a priori*
intuition plays a large role for Moore, he did not hold that one
attains moral knowledge exclusively by carefully focusing one's
attention on various moral propositions and then simply intuiting
whether or not they are true.


### 3.2 *Prima Facie* Moral Principles and Intuitionism



W. D. Ross (1930) is for many the paradigm intuitionist (see entry on
 William David Ross).
 He held both pluralism:



(P)
There is no single, fundamental moral principle.


and intuitionism:



(I)
We can have intuitive, *a priori* knowledge of moral propositions.


Even though (P) is not the focus of this entry, it might be useful to
review Ross's position on it. Ross provided principles
specifying various grounds of duty by using the concept of *prima
facie duty*. Ross thought of *prima facie* duty as a
tendency to be a duty, not as a kind of duty. He held that we have
*prima facie* duties to keep promises and tell the truth, to
provide reparation for harms we have done, to perform acts of
gratitude, to insure just distributions, to benefit others, to improve
ourselves, and not to harm others. He held that an act is a *prima
facie* duty in virtue of some one component of its nature, e.g.,
being a promise keeping. But a given act can have more than one
morally significant feature, and in virtue of some features it might
be *prima facie* right while also being *prima facie*
wrong in virtue of other features. Imagine a mob enforcer has taken a
contract to kill someone. The act of fulfilling his contract would be
a *prima facie* duty in virtue of keeping a promise, but it
would be *prima facie* wrong in virtue of harming, indeed,
killing, a person. The act would be wrong all-things-considered.
One's all-things-considered duty, according to Ross, is
determined by the entire nature of an action. Ross held that it is not
possible to provide a general ranking of *prima facie* duties
according to their stringency, with more stringent duties always
trumping less stringent duties if they conflict. And he did not think
it is possible to provide any other sort of general rule for
determining which *prima facie* duty will take precedence in
cases of conflict. Therefore, even if we had a set of principles
identifying every *prima facie* right making feature and every
*prima facie* wrong making feature--which Ross did not
claim to have provided--and even if we had complete knowledge of
the non-moral features of all actions, we could not mechanically
deduce which actions we would be duty bound to perform.



Turning now to (I): Ross held that his principles specifying *prima
facie* duties are self-evident. Here is a significant passage from
Ross articulating his view:



> 
> 
> That an act, *qua* fulfilling a promise, or *qua*
> ..., is *prima facie* right, is self-evident; not in the
> sense that it is evident from the beginning of our lives, or as soon
> as we attend to the proposition for the first time, but in the sense
> that when we have reached sufficient mental maturity and have given
> sufficient attention to the proposition it is evident without any need
> of proof, or of evidence beyond itself. It is self-evident just as a
> mathematical axiom, or the validity of a form of inference, is
> evident.... In our confidence that these propositions are true
> there is involved the same trust in our reason that is involved in our
> confidence in mathematics; and we should have no justification for
> trusting it in the latter sphere and distrusting it in the former. In
> both cases we are dealing with propositions that cannot be proved, but
> just as certainly need no proof. (1930: 29-30) 
> 
> 
> 



Ross here not only provides some clarification of his notion of
self-evidence, but also commits himself to a number of theses that are
typical of, or typically associated with, intuitionism (meaning (I)
specifically). By identifying these theses, we can begin to get a
clearer picture of Ross's intuitionism.



Ross claims that some propositions regarding *prima facie*
duties are self-evident. However, as Ross understands the
self-evidence of moral propositions, it is both stronger and weaker
than it is according to (SE).



The self-evidence Ross attributes to moral propositions is weaker in
that whereas on (SE) a self-evident proposition will be evident for
any person who understands it, according to Ross a self-evident moral
proposition is evident for any person who has attained sufficient
mental maturity and given the proposition sufficient attention. Hence,
on Ross's conception, a self-evident proposition,
*P*SE, might not be justified for some, and perhaps
even many, who understand it; *P*SE may not be evident
to persons who understand it if they either lack sufficient mental
maturity or have not considered *P*SE
 sufficiently.[6]
 Depending upon what is required for sufficient mental maturity and
sufficient consideration, self-evident moral propositions might be
evident, in virtue of their self-evidence, for precious few actual
individuals. Here's one way to think about it: Rossian
self-evidence has less epistemic potency--a person must satisfy
more conditions for a self-evident moral proposition to be evident
than merely understanding it.



If the requirements for sufficient maturity and consideration are
minimal, then there will be little difference between self-evidence as
defined by Ross and (SE). But Ross's approach would include a
"fudge factor" that might be useful. It could, e.g.,
enable him to avoid purported counterexamples where *S*
understands some self-evident moral proposition,
*P*SE, but we are disinclined to grant that
*P*SE is justified for *S* either because
*S* suffers from some general cognitive deficiency, e.g.,
excessive credulity, or the circumstances in which *S*
understands *P* are problematic for some reason, e.g., *S*
is exhausted or distracted. Ross could simply point out that *S*
lacks mental maturity or has failed to give *P*SE
sufficient consideration, and thereby avoid having to say that
*S* has a justification for *P*SE.



Ross's more restricted conception of self-evidence has another
potential advantage. We were all taught about morality. When children,
we were told, "Don't hit!" "Share your
toys", "You ought not lie", etc. And when older,
most of us encountered situations where it was not clear to us what we
should do, so we sought the advice of someone we trusted. In some of
these cases the moral propositions at issue may have been
self-evident, but at first the truth of these propositions was not
obvious to us, so we believed on the basis of testimony. One might
address these moral cases in the way we've suggested the
standard story could address analogous logical and mathematical cases.
That way of addressing the cases is not obviously mistaken, but one
might balk at the thought that a person who understands a self-evident
proposition automatically has a justification for that proposition
even before it is apparent to the person that the proposition is
true.



Ross's stronger requirements for self-evidence might provide a
more satisfactory account. Since on his view self-evident propositions
are evident for any person who has attained sufficient mental maturity
and given the propositions sufficient consideration, he could deny
that a child first being taught simple moral principles has a
justification for these principles and deny that a math student who
has been introduced to an "obvious" truth, but has not yet
had a chance to give it any consideration, would have a justification
for the truth. Ross could make the more plausible claim that if we had
a justification for these propositions at first, it was only because
of testimony. We did not, at first, have justifications for these
propositions on our own. Later, when we were mature and had given
these propositions due consideration, they would be evident to us on
their own.



Ross's conception of self-evidence is stronger than the standard
understanding because he held self-evident propositions are certain.
In the passage quoted, Ross does not explicitly claim that
self-evident propositions are certain, but he *suggests* they
are when he claims that self-evident moral propositions are like
mathematical axioms and logical truths. And two paragraphs later he
explicitly claims that our judgments regarding *prima facie*
duties are certain. (SE) asserts only that self-evident propositions
are evident, not that they are certain.



Three more elements of Ross's view deserve mention. First, the
standard story has it that self-evident propositions *can* be
justified without additional evidence, but does not rule out being
justified in believing a self-evident proposition on the basis of
evidence or even proof. But Ross claims that self-evident propositions
*cannot* be proved.



Second, Ross allowed that a person might come to be justified in
believing one of his general principles regarding *prima facie*
duties via what is sometimes called "intuitive induction".
One recognizes *prima facie* duties in particular cases first,
and then comes to apprehend the general principle. Thus, for example,
one intuits in a number of particular cases where one has promised,
that one has a *prima facie* obligation to do what one has
promised, and then one "sees" that one has a *prima
facie* obligation to keep promises. Intuitive induction is
supposed to produce *a priori* knowledge. When one knows on the
basis of an intuitive induction the justification for the general
principle is not derived from one's justifications regarding the
particular cases, as one would be in a standard enumerative induction.
Since Ross held that principles regarding *prima facie* duties
are self-evident, he was committed to the claim that their
justification does not depend upon anything else. So the idea must
instead be that thinking about the particular cases either enables one
to truly understand the general principle or is involved in giving it
sufficient consideration, whereupon one comes to see that it is
true.



Third, Ross denied that propositions regarding all-things-considered
duties in particular cases are self-evident. Indeed, he denied that
one can know what one's all-things-considered duty is in any
actual case; he held that this was a matter of "probable
opinion". In Ross's view, a *prima facie* duty
results from some one property of an action, e.g., that it is a
promise keeping or that it benefits some person. But one's
all-things-considered duty results from the entire nature of an
action. So one reason we cannot know our all-things-considered duty is
that we cannot know whether we have identified all the features of an
action that are morally relevant. And even if we could, there is the
additional problem that *prima facie* duties can conflict, and
it is not self-evident how such conflicts should be resolved.


## 4. *A Priori* Justification and Late 20th Century Naturalism



While hugely influential, Moore's open question argument is far
from unassailable. One influential response points out that it
implausibly assumes any correct definition or analysis must be
obvious. According to this response, the open question argument
implausibly assumes the correct response to the paradox of analysis is
to deny that any analysis could be both correct and informative (see
entry on
 analysis).
 So, the open question argument is no longer taken as decisive. In
addition, a majority of philosophers do not want to admit non-natural
entities into their ontologies. Finally, many judge that
non-cognitivist and anti-realist theories cannot really do justice to
the status of morality. It therefore is no surprise that naturalist
ethical theories, which hold that moral properties and facts just are
natural properties and facts, gained prominence towards the end of the
20th century. One such view, analytic naturalism, directly
contradicts Moore by holding that all ethical terms have naturalistic
analyses. It might seem that *a priori* justification would
play a prominent role in at least those naturalistic theories that
offer *analyses* of moral terms, but as we will see, this is
not so obvious (see entry on
 moral naturalism).



We will focus primarily on the role of the *a priori* in
analytic naturalism. However, perhaps a good entry point into the view
is via comparison with a very different view: Cornell realism.


### 4.1 Cornell Realism



Cornell realism (so named because its best known proponents are
associated with Cornell University) is a version of naturalistic
realism; it holds that there are moral properties (and thus moral
facts), but that moral properties are natural properties.



Epistemologically, there are two significant features of Cornell
realism. First, it accepts a coherence theory of justification.
Second, it applies to moral epistemology the claim from the philosophy
of science that observations are theory-laden. According to
coherentism, beliefs are not justified individually, but holistically,
in virtue of their membership in a coherent system of beliefs.
Especially within ethics, a coherent system of beliefs is often
referred to as being in a state of "reflective
equilibrium" (see entry on
 reflective equilibrium).
 The term "reflective equilibrium" is also used to refer
to an idealized method via which inquirers bring their moral beliefs
into coherence by reflecting on their considered moral judgments and
general principles intended to capture these judgments, and
eliminating any conflicts that emerge by making adjustments to either
the considered judgments or the general principles. Neither considered
moral judgments nor general principles are always favored. What the
inquirer revises in each case of conflict is determined by what seems
most likely to be true to the inquirer. A number of commentators on
reflective equilibrium have observed that it is a sophisticated
contemporary version of intuitionism in which considered moral
judgments, or more properly, the considered judgments and moral
principles that seem most likely to be true, play essentially the same
role in determining the moral theory eventually accepted that
self-evident moral intuitions did for earlier intuitionists.
Reflective equilibrium may allow for initially credible considered
judgments and moral principles to be revised more than one would
expect to see traditionally understood intuitions being revised, but
in the end what seems to be true upon reflection determines the system
of judgments and principles accepted in reflective equilibrium. Hence,
one might be tempted to assume that those who accept reflective
equilibrium, such as Cornell realists, are committed to *a
priori* justification playing a significant role in moral
epistemology even though what plays the role of intuitions is not
assumed to be self-evident. As we will see, this temptation should be
resisted.



Let's begin by noting that one influential criticism of
reflective equilibrium is that what seem to function as intuitions are
just what seem to the inquirer to be true; there is not even the
pretense that these have some special status, such as self-evidence.
Earlier intuitionists might be criticized for claiming propositions
are self-evident when they are not. But reflective equilibrium may
lead inquirers to do nothing more than build a coherent moral system
around strongly held beliefs that in fact have no positive epistemic
status. (We cannot pursue this criticism further but for an important
early response see Daniels 1979).



Observation of the vapor tracks made by charged particles in a cloud
chamber is a favorite example used to illustrate theory-laden
observation. A scientist could not observe, say, a positron, if the
scientist did not already believe various theories, e.g., regarding
sub atomic particles and how such particles will affect the medium in
the cloud chamber when they pass through it. But this does not mean
that experienced scientists make a theory-neutral observation of what
happens in a cloud chamber and then draw inferences regarding the sub
atomic particles from their theories and the theory-neutral
observation. That might have been what scientists had to do early on
in the development of the cloud chamber and the relevant theories. But
now when experienced scientists watch what happens in a cloud chamber,
they will spontaneously and non-inferentially form beliefs about
positrons, muons and the like; such spontaneous beliefs are real
observations. Experienced scientists make such observations in just
the way an ordinary person might observe a dog or cat in the front
yard.



Cornell realists hold that the same thing happens in the moral realm.
We all hold what is in effect a moral theory. The reasons we come to
hold the theory initially are not important, so long as the theory is
close enough to the truth. Richard Boyd (1988), for instance, suggests
that our background moral theory identifies moral goodness with those
properties that are conducive to the satisfaction of human needs, both
physical and psychological. Having internalized this theory, we are
able to make moral observations. For example, when we see photographs
of the prisoners at the Abu Ghraib prison during the American
occupation of Iraq we certainly recognize that treating persons in the
ways depicted frustrates some significant psychological needs. But
this will not be our primary reaction. When we view these photographs
we spontaneously judge that the treatment of the prisoners was wrong
or abusive (where it should be emphasized that the latter involves a
strong moral component). This spontaneous moral belief may be
dependent upon our background moral views; if we did not accept some
moral theory we would not have made it. But, according to the Cornell
realists, the belief is still an observation because it is
theory-laden rather than being inferred from a theory conjoined with
various non-moral observations. It is what happens in science, and as
in science, the fact that moral observations are theory-laden does not
prevent them from helping to support our moral theory. As in science,
explanatory relations are important, e.g., the fact that the prisoners
at Abu Ghraib were wrongly treated, where this fact of being wrongly
treated is something like the natural fact of their being seriously
harmed, is part of the best explanation of our observing that what was
done to them was wrong. On this view, neither the moral theory nor the
moral observations are epistemologically prior; both are justified in
virtue of the coherence of the entire system of moral beliefs.



The interesting feature of Cornell realism, for our purposes, is that
despite the fact that spontaneous moral beliefs--that some refer
to as intuitions--play a significant role, *a priori*
justification plays no significant role in its moral epistemology.
Both our more particular moral beliefs and our moral theories will be
justified in virtue of their coherence, not their self-evidence; the
considered moral judgments that are significant members of the
coherent system of moral beliefs, and that some see as old-fashioned
intuitions, are interpreted as observations, not rational insights.
For Cornell realism, the justification of our moral beliefs crucially
depends upon experience, specifically, moral observation.


### 4.2 Analytic Naturalism



Cornell realism holds that moral properties cannot be *a
priori* analyzed as any natural properties, though they can be
empirically discovered to be identical to certain natural properties.
In contrast, analytic naturalism holds that moral properties can be
analyzed in terms of natural properties. One influential version of
analytic naturalism applies to moral properties a strategy that was
developed for dealing with mental properties, which is why the view is
also called moral functionalism, flagging the similarity to
functionalism in the philosophy of mind. We will focus on this version
of analytic naturalism, specifically Frank Jackson's (1998)
exposition. (For another version see Stephen Finlay 2014.)



To a first approximation, analytic naturalism holds the following:
There are many statements containing moral terms that we find obvious
or intuitive--moral platitudes, if you will. These statements
constitute a sort of folk moral theory. Here are some examples:
"intentional killing is normally wrong", "pain is
bad", "virtuous people are more likely to do the right
thing than vicious people", "a person who judges that she
ought to do something normally feels some motivation to do it".
Collectively, such statements fix the reference of moral terms, i.e.,
they determine what moral terms refer to. If a person denied enough of
these statements, we would conclude that the person did not use moral
terms with the same meaning as the rest of us. According to analytic
naturalism, moral terms have their meaning holistically, as a result
of the role they play in the system of moral statements that make up
folk morality. Significantly, many of these statements relate moral
properties to each other, as does the statement that virtuous people
are more likely to do the right thing.



There is an immediate problem. Since current folk morality is made up
of all the moral statements that many people find obvious, given the
level of moral disagreement, folk morality is unlikely to be
consistent. If it contains inconsistent statements folk morality will
not be able to determine the reference of moral terms, since an
inconsistent description does not apply to anything. Moreover, parts
of it that seem obvious to many people are likely to be grounded in
superstitions, depend upon empirical views that are mistaken, and in
various other ways not be able to stand up to critical reflection. So
current folk morality must be cleaned up. One way to think about
cleaning up folk morality is as trying to bring it into reflective
equilibrium. But however it is done, the point is to mold current folk
morality into a coherent, reflectively defensible system of moral
beliefs: a mature folk morality. Analytic naturalism claims that the
meaning of moral terms is given by the role they occupy in the
statements that constitute mature folk morality.



To see more specifically how this works, imagine writing down all the
statements of mature folk morality as one long conjunction.
Simplifying, suppose mature folk morality consists of only the first
three examples above:



> 
> 
> *Intentional killing is normally wrong* and *pain is
> bad* and *virtuous people are more likely to do the right thing
> than vicious people*. 
> 
> 
> 



We can transform these statements so that they explicitly reference
moral properties and replace each moral property term with a distinct
variable:



> 
> 
> *Intentional killings normally have the property *w** and
> *pain has the property *b** and *people with the
> property *v*1 are more likely to perform actions
> having the property *r* than people having the property
> *v*2*. 
> 
> 
> 



We then bind all these variables with existential quantifiers to
get:



> 
> 
> There exists a property *w* and a property *b* and a
> property v1 and a property *r* and a property
> *v*2 such that *intentional killings normally have
> the property *w** and *pain has the property *b**
> and *people with the property *v*1 are more likely
> to perform actions having the property *r* than people having the
> property *v*2*. 
> 
> 
> 



We now have a sentence that says there are five properties that
fulfill the roles played by the moral properties we began with. But
that's not good enough to single out moral properties by their
playing these roles, since there might be other properties that also
play these roles. To exclude this possibility, we need to add a claim
saying that only one property plays each role, i.e., a clause that
states that any property that makes all the statements containing
*w* true is identical to *w*, any property that makes all
the sentences containing *b* true is identical to *b*, and
so on. We can abbreviate this clause as *Uniqueness.* It is now
possible to define any moral term using the complicated sentence we
have just constructed. For example:



> 
> 
> Wrongness is the property *w* such that: there exists a property
> *b* and a property *v*1 and a property *r*
> and a property *v*2 such that *intentional killings
> normally have the property *w** and *pain has the property
> *b** and *people with the property *v*1
> are more likely to perform actions having the property *r* than
> people having the property *v*2* and
> *Uniqueness*. 
> 
> 
> 



The claim that this simple statement correctly analyzes wrongness is
not very plausible. But that is because we simplified, including only
three statements from mature folk morality. Analytic naturalism holds
that the extremely complex sentences constructed in the same way using
*all* of mature folk morality provide analyses of moral terms.
This position is much more plausible, although still
controversial.



One might at this point question why the analyses of moral terms
analytic naturalism constructs would be naturalistic, i.e., define
moral terms in purely "descriptive" terms, given that the
roles played by moral terms are partly determined by their relations
to other moral terms. A crucial element of the view that we must now
explain addresses this question. Analytic naturalism holds that a
central tenet of folk morality is that moral properties
*supervene* on natural properties. This means that it is
impossible for two situations to differ morally without there also
being some natural difference. Jackson argues that the supervenience
of the moral on the natural, or as he prefers, on the
"descriptive", entails that moral properties are natural
properties.



Take any ethical statement *E*. Since moral properties are
supervenient or *consequent* upon descriptive properties, no
possible world where *E* is true can be made up only of moral
facts. There will also have to be descriptive facts about this world,
so there will be a sentence, likely an extremely long and complex
sentence, that completely specifies the descriptive facts about the
world. There will be such a purely descriptive sentence for every
possible world where *E* is true. Let these sentences be
*D*1, *D*2, *D*3,
... We can disjoin all these descriptive sentences to get
*D* = (*D*1 or *D*2 or
*D*3 or ...). D will also be a descriptive
sentence; it is made up entirely of descriptive sentences put together
using "or", which is not a moral term.



Now, although it is an odd sentence--a very long
disjunction--there is an important fact about *D*: it
entails *E* and it is entailed by *E*. If *E* is true,
then one of the disjuncts of *D* must be true, because *D*
contains a disjunct describing every world where *E* is true;
hence, *D* will be true as well. On the other hand, if *D*
is true, then one of its disjuncts must be true, say it is
*D**n*. *E* could not be false in a world
described by *D**n* because
*D**n* is included as a disjunct of *D*.
Hence, if *E* were false in a world described by
*D**n* it would be possible for there to be two
worlds that were exactly alike in all descriptive respects with the
moral statement *E* being true in one of these worlds but false
in the other. The supervenience of the moral on the descriptive tells
us that this cannot happen--there can be no moral difference
unless there is some descriptive difference. So *D* entails
*E*.



Jackson concludes,



> 
> 
> The same line of argument can be applied *mutatis mutandis* to
> ethical and descriptive predicates and open sentences: for any ethical
> predicate there is a purely descriptive one that is necessarily
> co-extensive with it. 
> 
> 
> 



> 
> 
> It follows that ethical properties are descriptive properties. (1998:
> 122-123) 
> 
> 
> 



One could question Jackson's assumption that necessarily
co-extensive properties are the same, but we cannot here pursue that
issue. What analytical naturalism offers so far is an analysis of
moral terms and an argument that moral properties are natural, or
descriptive. But exactly which descriptive properties are identical to
the moral properties? Analytic naturalism does not tell us this now.
It claims that once we have attained a mature folk morality, we will
be able to determine which natural properties fulfill (closely enough)
the roles of the various moral
 properties.[7]



Given that analytic naturalism provides analyses of moral
terms--more exactly, a procedure for constructing such analyses
once we have a mature folk morality--one might conclude that
various moral propositions will be *a priori* justified, most
significantly, the definitions of moral terms. Jackson claims as much.
Explaining the "*a priori*" supervenience of moral
on descriptive properties, e.g., he writes, 



> 
> 
> It is an implicit part ... of our understanding of ethical terms
> and sentences that they serve to mark distinctions among the
> descriptive ways things are. (1998: 125) 
> 
> 
> 



He also claims that the characterization of the role played by
rightness and the other moral terms in mature folk morality is *a
priori* while the identification of exactly which natural
properties play these roles is *a posteriori*, since this would
require empirical investigation. Jackson describes mature folk
morality as 



> 
> 
> the best we will do by way of making good sense of the raft of
> sometimes conflicting intuitions about particular cases and general
> principles that make up current folk morality. (1998: 133) 
> 
> 
> 



Mature folk morality is just the result of subjecting current folk
morality to sustained critical reflection.



It is worth noting, however, that although Jackson's description
of the status of the supervenience of the moral on the natural is
suggestive, he does not explicitly claim that even this is
self-evident. Although his descriptions of folk morality, e.g., as




> 
> 
> the network of moral opinions, intuitions, principles and concepts
> whose mastery is part and parcel of having a sense of what is right
> and wrong, and of being able to engage in meaningful debate about what
> ought to be done (1998: 130) 
> 
> 
> 



suggest that one could determine, *a priori*, the content of
folk morality, folk morality is also clearly something held by a
community of people rather than an individual. This suggests that
empirical inquiry would be needed to determine what belongs to the
folk morality of a community, including even the community to which
one belongs. Finally, there is the critical reflection that produces
mature folk morality. Jackson does not describe this reflection in
much detail. He mentions reflective equilibrium as one example, but
reflective equilibrium is understood in various ways, and most include
empirical elements. So while there are some reasons to think
analytical naturalism allows for significant *a priori* moral
justification and knowledge, there are also grounds for doubt. (For an
argument that analytic naturalists must make use of a priori
equivalences between moral and descriptive features, see Smith
2000.)


## 5. Moral Particularism and Justification



Moral particularists accept some disambiguation of at least one of the
following two theses:


1. There exist no true moral principles.
2. One should not use moral principles in the course of moral
deliberation.



If any version of the first thesis is true, then *a fortiori*
there is no *a priori* knowledge of any moral principle, since
there are no true moral principles. Moreover, particularists who
accept the first thesis are distinct from Rossians in that they reject
the existence of true *pro tanto* moral principles such as that
promise-keeping is a *pro tanto* duty. (Contemporary
particularists, and moral philosophers more generally, tend to prefer
*'pro tanto'* to Ross's *'prima
facie'*, which even Ross admitted was unsatisfactory
immediately upon introducing it. The problem with *'prima
facie'* is that it means *at first glance*, but a
*prima facie* duty is not something that seems to be a duty at
first glance, but something that would be a duty if it is not
overridden in some way. *'Pro tanto'* means *to
that extent*, and a *pro tanto* duty is something that
would be a duty *sans phrase*, if it were not overridden in
some way.) Thus, particularists believe that one cannot know *a
priori* any *pro tanto* principle. However, as we'll
see, these particularists nevertheless think one can attain knowledge,
even *a priori* knowledge, of particular moral facts.



Most particularists also accept the second thesis. In some cases,
particularists accept the second thesis because they accept the first
(Dancy 2005, McDowell 1979). In other cases, particularists reject the
first thesis but accept the second: they admit that there are some
true moral principles, but hold that those principles are nevertheless
*not* the sorts of things that should play a role in
deliberation (Guarini 2006). However, all particularists who accept
the second thesis tend to adopt a similar moral
epistemology--let's call the second thesis
"abstinence".



There are other particularists who accept the first thesis and reject
the second, and admit that there are some false moral
principles--distinct from *pro tanto* moral
principles--that are appropriate to use in some deliberative
situations (Little 2000). Let's call this view "rule of
thumb" particularism.


### 5.1 Abstinence



Jonathan Dancy accepts versions of both the first and second thesis,
and he accepts the second thesis in part because he accepts the first.
Dancy holds that there are two types of principles: *absolute*
and *contributory*. An absolute moral principle specifies a
sufficient condition for the instantiation of a moral property, while
a contributory moral principle specifies that a feature has an
intrinsic moral valence (see entry on
 Dancy's moral particularism).
 Dancy holds that neither sort of true principle exists, and thus
neither sort of principle can properly play a role in moral
deliberation--after all, using false moral principles could lead
us to act correctly for the wrong reasons, or to act incorrectly
(Dancy 2005: 3).



Moreover, Dancy holds that neither sort of principle is necessary for
responsible moral deliberation. In this respect, Dancy's view is
similar to Moore's, albeit only on the level of particular moral
facts. According to Dancy, morally sensitive people can intuit the
morally relevant features in a context, thereby intuiting the moral
reasons in that context, and reliably come to a correct moral
conclusion about how they ought to act, even without the use of a
principle that specifies how to weigh one's reasons. (In this
latter respect, Dancy's view is also similar to Ross's.)
In some cases, Dancy has suggested that we can understand this
deliberative process by looking to connectionist machines or Roschian
prototype theory (Dancy 1999).



Particularists rarely put their account of moral knowledge in terms of
justification. But when particularists do put their view in terms of
justification (see below) they claim that the justification involved
is *a priori*. The thought seems to be this: if one can issue a
moral verdict in a particular case on the basis of the moral reasons
one is presented with in that case, then one must know what those
reasons are, as well as how to weigh them to reach a verdict. But,
according to particularists, there are no principles one can use to
know those things; thus, one must see--through the exercise of
intuition--what one's reasons are and how to weigh them
against each other. That is, one must intuit propositions such as
**R* is a reason to ph in this case* and *In this
case, on balance, the reasons support ph-ing*. Particularists
seem committed to a version of the modified standard view of *a
priori* justification. There is a distinct experience of rational
"seeing"" in virtue of which one is *a
priori* justified in believing these propositions regarding a
particular case. If the propositions one is thereby justified in
believing are self-evident, it seems that they are self-evident only
in the attenuated sense that it is possible to have rational insight
into their truth, and hence possible to be justified in believing
them, solely on the basis of understanding them and thinking about
them. It is also worth taking note that the moral propositions
particularists hold that we are *a priori* justified in
believing are relative to a particular context: what one can come to
see is that something is a reason to ph for a particular agent in a
particular situation or that the balance of reasons support ph-ing
for this particular agent in this particular situation.



The role of past experience in present moral deliberation complicates
the particularist's claim that moral beliefs are justified *a
priori*. On the one hand, particularists claim that past
experience plays an important role in deliberation, even for the
morally mature agent--for instance, one often judges that
*R* is a reason in the present context because *R* was a
reason in a relevantly similar context in the past (see the entry on
 Dancy's moral particularism).
 But on the other hand, the belief one arrives at through this kind of
reflection on past experience is nevertheless *a priori*,
according to particularists. How can we make sense of the conjunction
of these two claims?



Perhaps we can try to answer this question by looking at what
abstinence particularists--Dancy in particular--have to say
about Kant. Dancy writes that particularists agree with Kant that
moral judgments are synthetic *a priori*. According to Dancy,
Kant inferred from this that moral judgments must also be necessary
and universal (2007); but particularists reject this inference, and
hold that moral judgments are synthetic *a priori* and yet are
contingent and particular. Dancy writes,



> 
> 
> Does it follow from this [that moral facts are contingent and not
> universal] that they [moral facts] are not knowable *a priori*?
> I don't think so. After all, even when all the empirical
> information--that is, the information that we think of as
> ordinarily available to the senses--is in, we still have to
> determine which aspects of the present situation, as revealed to us in
> experience, count which way as reasons. That decision seems to take us
> beyond anything that the senses can inform us about.... Even if
> we have the benefit of previous experience [that in the past, the fact
> that I was dealing with someone in distress was a reason to go
> gently]..., the most we can get out of that is the recognition
> that her distress is *probably* a reason. Now this sort of
> knowledge would only be *a posteriori* if the evidence on which
> it is based is *a posteriori*. And that just returns us to the
> primary question here: in a case where we don't have the benefit
> of previous experience, is the "process" by which we come
> to recognize that her distress is a reason, one that can be thought of
> as taking us from *a posteriori* knowledge (that she is in
> distress) to another *a posteriori* knowledge (that her
> distress is a reason to go gently)? And the answer seems to me to be
> no. If our decision that it is a reason is capable of counting as
> knowledge, then, it seems that it will have to be *a priori*
> knowledge that is at issue, since we only have two choices--*a
> priori* and *a posteriori*--and the latter is ruled
> out. (Dancy 2007) 
> 
> 
> 



Dancy appears to endorse this argument:


1. If I come to know/justifiably believe a moral
proposition, then I'm either relying on past moral experience or
I'm not.
2. If I'm *not* relying on past moral
experience, then my conclusion is *not* known/justified *a
posteriori*.
3. An item of knowledge/a justified belief is either
known/justified *a priori* or *a posteriori*.
4. Thus, if I'm *not* relying on past moral
experience, then my conclusion is known/justified *a priori*.
(2, 3)
5. If I'm relying on past experience and the past
conclusions I'm relying on are known/justified *a
priori*, then my present conclusion is known/justified *a
priori*.
6. Thus, if I'm relying on past moral experience,
then my conclusion is known/justified *a priori*. (4, 5)
7. Thus, if I come to know/justifiably believe a moral
proposition, my knowledge/justification is *a priori*. (1, 4,
6)



The contentious premises in this argument are premises
 5
 and
 2.
 One might offer the following sort of counterexample to
 premise 5.
 Let's say that in the past, I've added together many
pairs of even numbers; and in each of those cases, I've
known/justifiably believed (*a priori*) that the sum of the two
numbers was also even. Then someone asks me: is it always the case
that the sum of two even numbers is itself even? Assume that, for
whatever reason, I'm genuinely uncertain of the answer--I
don't see the answer intuitively, or perhaps I doubt my more
general mathematical intuitions. Nevertheless, I realize that in the
past, whenever I've added two even numbers the sum has itself
been even. Thus, I inductively infer that the hypothesis is correct:
the sum of two even numbers is always itself even.



This example seems like a paradigm case of one coming to
know/justifiably believe an *a priori* proposition *a
posteriori*. So, with the distinction between an *a priori*
proposition--a proposition amenable to *a priori*
justification--and *a priori* justification/knowledge in
place, one might be tempted to reject
 premise 5.



Moreover, more support is needed for
 premise 2.
 Many paradigm cases of *a posteriori* justification do not
rely on past experience. Take, for example, your belief that the
traffic light is red. Past experience, in this case, only provides you
with the relevant concepts needed to understand the proposition
*the traffic light is red*. What justifies your belief is the
current experience of the traffic light's being red--and
surely this yields *a posteriori* justification! Perhaps Dancy
could say something like this: if I infer a moral claim from an
empirical matter of fact (as when I infer that the fact that I'm
dealing with someone in distress is a reason to go gently on the basis
of my experience of her distress), then I'm going beyond my
empirical experience in a way that's different from when I infer
that the traffic light is red on the basis of my empirical experience.
But Dancy would need to say more about this distinction to explain why
the former is an example of *a priori* justification and the
latter an example of *a posteriori* justification. (For further
arguments against the particularist's claim that it's
possible to have a priori knowledge of particular, contingent moral
facts, see McKeever and Ridge 2006, especially chapter 7.)



Nevertheless, Dancy's take on Kant, in spite of his
argument's weaknesses, gives us some insight into how Dancy must
see the role of experience in *a priori* justification. Dancy
must think that when I infer on the basis of my current experience of
a particular situation that *R* is a reason to ph, my
inference is different from the kinds of inferences that yield *a
posteriori* justification, and for this reason particularism is
compatible with moral knowledge being *a priori*.


### 5.2 Rule of Thumb Particularism



According to rule of thumb particularists, one need not give up the
use of all moral principles in moral deliberation, because there are
some false moral principles that are reasonable to employ. Margaret
Little, for instance, thinks that there are no true moral principles
(not even principles that express *pro tanto* reasons or
obligations), but that there are false, defeasible principles that can
nevertheless provide presumptive epistemic warrant for moral beliefs.
Little holds that we can know with reasonable certainty--on the
basis of experience and testimony--what sorts of contexts
we're likely to encounter, as well as which features tend to
count as reasons (and for what) in those sorts of contexts. She
writes,



> 
> 
> The judgement that a given principle such as "lying is
> wrong" will help rather than mislead a moral novice reflects a
> judgment about the sorts of contexts she is likely to encounter, just
> as our agreement that it is better training to tell beginner drivers
> "Never slam on the brakes" instead of "Stomp on the
> gas whenever you see another car" reflects a judgement that the
> student will most likely be facing our world of crowded highways and
> not the post-apocalyptic world of Mad Max movies. (Little 2000: 295)
> 
> 
> 
> 



This view--that there are defeasible moral principles we can
legitimately use in deliberation--may seem at odds with the
particularist claim that there are no *pro tanto* moral
principles. However, Little sees no such tension. The existence of a
principle that expresses a *pro tanto* reason or obligation
entails that certain features have intrinsic moral natures that give
them a default "moral valence". To say, "Lying is
*pro tanto* wrong", is to assert that lying has a default
negative moral valence, that the feature of being a lie in and of
itself makes an action worse, even if that feature's moral
contribution could be outweighed by other considerations. However,
according to Little, the existence of defeasible generalizations
doesn't entail any such thing; it simply turns out that lying
tends to be wrong in the contexts most humans tend to encounter, even
though lying, in and of itself, has no intrinsic moral valence. Since
the latter is (close to) a mere defeasible statistical generalization,
its use can allow one to justifiably come to moral beliefs even though
(a) it's strictly false and (b) it strictly says nothing about
the intrinsic moral nature of a property.



This isn't to say that Little thinks this is the only way we
come to hold justified moral beliefs--perhaps we could achieve
moral knowledge or justification by engaging in a cognitive process
like that described by Dancy (a process by which one intuits, in a
context, what the reasons in the context are and how one ought to
weight them against each other). But Little does think that
particularism will be too demanding if it requires that one form all
moral beliefs in the way Abstinence prescribes.



To sum up, rule of thumb moral particularism makes room for *a
posteriori* moral knowledge and *a posteriori* moral
justification. Although it leaves open the possibility that some moral
knowledge and justification is *a priori* (in the way Dancy
describes), it denies that all moral knowledge/justification is *a
priori*; rule of thumb particularists hold that one can
justifiably infer at least some moral conclusions from experience,
testimony, and (experience-supported) beliefs about the kinds of
contexts one is likely to encounter.


## 6. *A Priori* Justification and Early 21st Century Intuitionism



Ethical intuitionism fell on hard times in the second half of the
20th century. But as the century closed and moving into the
21st century, a number of able defenders of the view came
forward, e.g., Robert Audi (2004), Michael Huemer (2005), Russ
Shafer-Landau (2005), Ralph Wedgwood (2007) and John Bengstrom,
Terence Cuneo, and Russ Shafer-Landau (2019). (For good introductions
to the recent discussion of intuitionism see Stratton-Lake 2002 and
the entry on
 intuitionism in ethics.)
 Perhaps the resurgence of ethical intuitionism is in part a result of
the increased attention philosophers have been paying to the role of
intuition in philosophical inquiry more broadly. (A good starting
point for this topic is provided by the essays in DePaul and Ramsey
1998, and see the entry on
 intuition.)
 We will close with an examination of the version of this "new
intuitionism" presented by Audi--which he calls
"moderate rationalist intuitionism" (Audi
2020)--focusing on the epistemological side of his position.



Audi's version of intuitionism is very much in the spirit of the
earlier intuitionism espoused by Moore and especially Ross. He
moderates a number of elements of their intuitionism, highlights
others, and arguably breaks with at least Ross on one significant
point. We will begin with two ways in which his intuitionism softens
elements of theirs.



First, earlier intuitionists did not consistently distinguish between
two roles for necessity or self-evidence. Moral intuition might
consist in apprehending that some moral proposition is necessary, or
that it is self-evident. Or moral intuition might consist in just
apprehending some moral proposition's truth, while the
proposition is in fact necessary or it is in fact self-evident. As a
result, the earlier intuitionists often suggest our knowledge of
fundamental moral principles is grounded in recognition of either the
necessity or self-evidence of these principles. This imposes too
strong a requirement on the *a priori* justification of moral
principles. We cannot expect ordinary people to possess technical,
philosophical concepts such as necessity and self-evidence. But there
is no need to exclude ordinary people who lack these concepts from
having *a priori* knowledge of ordinary moral propositions,
e.g., that pain is bad or that promising to do something provides a
moral reason for doing it. And even if an ordinary person does have
the concepts of necessity and self-evidence, there is no reason to
deny that the person knows ordinary moral propositions *a
priori* when she or he believes them on the basis of understanding
them, without noting their modal status (as necessary) or epistemic
status (as self-evident). Doing so is not required by the standard
account of self-evidence. Audi is very clear about the distinction
between apprehending the necessity or self-evidence of a proposition,
and apprehending the truth of a proposition that is necessary or
self-evident. He does not require the former in order to have *a
priori* knowledge of fundamental moral principles (2004:
41-45).



Audi stresses a second point, one we mentioned when discussing Ross.
The earlier intuitionists held that there was no reason or evidence
for self-evident moral principles and that they *could not* be
proven. Examining why they might have made such strong claims would
take us too far afield. It is sufficient to note that there is no need
for intuitionists to make them. What's important for their
overall position is the possibility of being non-inferentially
justified in believing fundamental moral principles. This does not
require that it is impossible to provide reasons or evidence or even a
proof for any moral principle. Audi's intuitionism takes the
more moderate position that self-evident moral principles *can*
be justified without reasons, evidence or proof (2004:
51-54).



There is an important element of Ross's intuitionism that Audi
does not moderate, but instead makes more of than Ross. We previously
noted that Ross's conception of self-evidence is more restricted
than the standard conception in that self-evident propositions are
evident to those who have reached sufficient mental maturity and given
them sufficient attention, rather than to anyone who understands them.
The more restricted understanding allows an explanation of why people
who understand a self-evident proposition might nevertheless not have
a justification for believing it. On the plausible assumption that
there is a close connection between what is evident for a person and
what a person believes, Ross's weaker conception also suggests
an explanation of why some people who understand a self-evident
proposition might believe it while others do not. Audi uses different
terminology from Ross, formulating the relevant condition on
self-evidence in terms of "adequate understanding". But
for Audi adequate understanding requires rather more than mere
semantic comprehension, and, in the end, his view is probably quite
close to Ross's. Audi's view of adequate understanding
emerges when he explains how reasonable people could disagree about
self-evident moral propositions as well as how one might continue to
be justified in spite of disagreement (see 2015: 67-72). So Audi
develops and does important work with the possibilities Ross's
more restricted conception of self-evidence opened up, but Ross did
not much explore.



We now come to the point where Audi arguably breaks with much earlier
thought regarding intuitionism. A second element of the earlier
intuitionism that Audi emphasizes concerns the connection between
intuition and belief. Neither Moore nor Ross made much use of
"belief" and cognate terms. One can nevertheless make a
fairly strong case that Moore probably would not have agreed that
intuitions are beliefs. Ross is more difficult, but there is a strong
temptation to interpret him as holding that intuitions are beliefs
when he writes, e.g., that "the moral convictions of thoughtful
and well-educated people are the data of ethics" (1930: 41).
Many who have written about intuitions or intuitionism follow Ross so
interpreted, assuming that intuitions are beliefs. Audi follows the
lead of a number of contemporary writers on intuition (beginning with
Bealer 1998) in recognizing the significance of what Audi calls
"episodic intuitions". Episodic intuitions are
"intellectual seemings--a phenomenal, attentional sense of
the truth of the proposition in question" (Audi 2015: 61). When
we have an episodic intuition, we tend to believe the proposition
intuited. But it is significant that one can have an episodic
intuition without believing. Bealer illustrated the point with the
naive comprehension axiom of set theory. He reports that when he
considers this axiom on its own, it seems true to him. But he does not
believe the axiom, because he knows that it leads to
 paradox.[8]
 Interestingly, the intuition persists in spite of the recognition
that the axiom is false. Many people share Bealer's experience.
Bealer notes that his example is a purely intellectual analog of the
Muller-Lyer illusion: In spite of knowing that the lines in the
illusion are equally long, they continue to
seem--visually--to have different lengths.



It follows that episodic intuitions are not beliefs. Some writers hold
that episodic intuitions are dispositions or felt dispositions to
believe (see, e.g., Sosa 1998 and Williamson 2007). Others hold that
episodic intuitions are *sui generis* propositional attitudes
(see, e.g., Bealer 1998 and Huemer 2005). Audi seems to side with
those who hold episodic intuitions to be *sui generis*
propositional attitudes.



Bealer's example shows that we can have episodic intuitions of
false propositions and propositions that are not self-evident. Audi
argues that one might adequately understand a self-evident proposition
and fail to have an episodic intuition of it using as an example the
proposition that "a child can be borne by its grandmother"
(2015: 65). He claims that this proposition is self-evident--to
figure out why it is true, think of Oedipus Rex--but denies that
it is intuitive, noting that some people even have an episodic
intuition of its falsehood.



Audi claims that Ross and other earlier intuitionists realized that
not all intuitions had self-evident propositions as their objects. It
is not obvious that they did, but we cannot pursue the issue. They
certainly did not make a sufficient fuss about episodic intuitions to
avoid being widely interpreted as holding that the intuitions
responsible for our knowledge of morality are all beliefs in
self-evident propositions. So Audi at the very least breaks with one
common understanding of the earlier intuitionist position.



Episodic intuitions are epistemically and methodologically important
for Audi. Here is a representative passage: 



> 
> 
> An episodic intuition, as an experience, does not stand in need of
> justification and may confer it. Like sense experience, it is only a
> fallible indicator of truth; but much as we cannot navigate the
> physical world without sense experience, we cannot adequately pursue
> truth in ethics or elsewhere without intuition. (2015: 65) 
> 
> 
> 



It is very clear that on the earlier intuitionist view, the
justification for fundamental moral principles was *a priori*.
What about Audi's intuitionism? Since he does allow that some
moral principles are self-evident, and that when a person believes
such a self-evident proposition on the basis of adequate
understanding, the person knows, he recognizes a place for *a
priori* moral knowledge. But what about beliefs in moral
propositions that are not self-evident, but are formed on the basis of
episodic intuitions? Audi holds such beliefs can be justified, but is
the justification *a priori*? As is indicated by the analogy
with sense experience that Audi stresses, episodic intuitions are
decidedly experiences. When a belief formed on the basis of an
episodic intuition is justified, its justification depends upon the
experience and hence is not independent of experience except for the
experience necessary to acquire the relevant concepts. One can regard
such beliefs as justified *a priori* only if one adopts the
modified standard view of the *a priori*, which holds *a
priori* knowledge and justification to be independent of
perceptual, introspective, memorial and all other
experiences--*except for the experience of rational
intuition*. (For a more recent treatment of these issues, see Audi
2020.)



In closing, it is interesting to note that the version of contemporary
intuitionism defended by Huemer (2005) also pushes one towards the
modified standard view. The epistemological side of Huemer's
ethical intuitionism is a natural outgrowth of his general
epistemological position, which he calls phenomenological
conservativism. According to phenomenal conservativism, if it seems to
one that a proposition is true, then one is *prima facie*
justified in believing that proposition. Significantly, the specific
kind of seeming--perceptual, from memory, by reasoning, or
otherwise--is irrelevant to the seeming's capacity to
justify. Huemer's phenomenological conservativism holds that all
our beliefs are based on how things seem, and hence that unless
seeming true justifies us in believing, we could not be justified in
believing anything. Phenomenal conservativism drives one to the
modified standard view of the *a priori* because the
intellectual seeming is what justifies. One might be concerned that
the modified standard view understands the distinction between
rational intuition and all other kinds of seemings to be very
significant epistemically--it is what marks the crucial
distinction between the *a priori* and the empirical--but
for phenomenological conservativism it is all just seemings, with no
kind of seeming playing any different epistemological role from any
other kind of seeming. One might allay the concern by noting that the
modified standard view already admitted a role for experience in *a
priori* justification, but distinguished the experience of
rational intuition or intellectual seeming from all other kinds of
experience. Nevertheless, when considering contemporary versions of
moral intuitionism, especially when combined with phenomenological
conservativism, it is hard not to notice that, if intuitive moral
knowledge as these views conceive it is *a priori*, then the
operative conception of the *a priori* has strayed a
considerable distance from the old root idea of independence from
experience.