## 1. The Distribution of Modality



Spinoza's list of the basic types of existing things is
exceedingly short: substances and modes
 (Ip4d).[2]
 Spinoza gives two extremely different, but equally striking accounts
of how many tokens exist under each of these two basic types. There is
only one existing substance, God, and there are infinitely many modes.
Without yet unpacking these claims, we might ask Spinoza, "But
could there have been *more* substances or *fewer* modes
than there in fact are?" Or, keeping the number of tokens fixed,
"Could there have been a *different* substance or
*different* modes than the ones that in fact exist?"
Surprisingly, Spinoza seems inclined to answer "no" to
these questions. If so, then Spinoza thinks the actual world is the
only possible world. This is the position of
*necessitarianism*, a belief that few in the history of Western
philosophy have explicitly embraced. And for good reason -- on
the face of it, necessaritianism is highly counterintuitive. Surely
the world could have gone slightly differently than it has gone.
Couldn't the Allies have lost WWII? Couldn't a leaf have
landed an eighth of a centimeter farther to the right than it in fact
landed? Similarly, surely the world could have contained different
individuals in different numbers than it in fact contains.
Couldn't Leibniz have had a sister or not been born at all?



Spinoza was aware of how deeply against the grain of common sense the
truth of necessitarianism would run. If he nonetheless believed in its
truth, he must have thought he had very compelling reasons for doing
so. What might such reasons be? We will begin with substance
necessitarianism (2.1) and then turn to the necessity of modes (2.2).
Although the case for interpreting Spinoza as a mode necessitarian is
strong, there are also Spinoza-friendly reasons for resisting such a
reading. Seeing this tension will lead us into the middle of an
interpretive controversy that has ramifications for understanding many
of Spinoza's other central metaphysical views. (In section 2, we
will undercover one possible way of reconciling Spinoza's drive
towards necessitarianism with what might have been equally important
reasons for avoiding it.)


### 1.1 Substances



In the case of substances, Spinoza claims that every existing
substance necessarily exists (Ip7d). No existing substance could have
failed to exist. He also claims that only one substance, God, actually
exists and that only this one substance *could* have existed
(Ip14). Putting these claims together, Spinoza believes that every
possible substance necessarily exists. Since God is the only possible
substance, it is impossible for any other substance besides God to
exist.



Spinoza's argument for these conclusions can be divided into two
major stages:


1. Every possible substance necessarily exists.
2. God is the only possible substance.



Let us consider Spinoza's reasoning for each of these steps in
turn, as doing so will help us understand some of Spinoza's most
important and basic metaphysical commitments.



In arguing for (1), Spinoza relies on two implicit and related
premises. One is the
 principle of sufficient reason
 (PSR) and the other involves his account of causation. Put roughly,
the PSR states that every fact has a reason for obtaining; in slogan
form, *there are no brute facts*. Most relevantly for our
purposes, if something existed for no reason at all, the fact that it
exists would be inexplicable, a violation for the PSR. And for
parallel reasons, if something did not exist and there was no reason
for its non-existence, the fact of its non-existence would also be a
violation of the PSR. As Spinoza puts it, "For each thing there
must be assigned a cause or reason, both for its existence [if it
exists] and for its non-existence [if it does not exist]. For example,
if a triangle exists, there must be a reason or cause why it exists;
but if it does not exist, there must also be a reason or cause which
prevents it from existing, or which takes its existence away"
(Ip11d). Thus, according to the PSR, there must be sufficient reasons
why each existing substance exists and also sufficient reasons why
non-existing substances do not exist.



The second implicit premise of Spinoza's argument for the claim
that all possible substances necessarily exist is that *causes*
provide (or just are) necessary and sufficient explanatory reasons.
This idea appears in the previously quoted passage in which Spinoza
claims that citing a "cause or reason" suffices for
explaining facts about the existence and non-existence of a triangular
object. Applied to the case of substance, the sufficient reason for
why a substance exists is supplied by the causes of that
substance.



Why does Spinoza think that an account of an object's causes
explains that object's existence? His most revealing answer
traces back to the PSR as well. Because facts about the nature of
causation are facts, by the PSR, facts about causation require
explanation too. In a case in which *x* causes *y*, the
PSR demands an explanation of what it is in virtue of which the causal
relation between *x* and *y* obtains. Although one may
try to answer this question by appealing to other causes (say,
*z*'s causing *x* to cause *y*), the PSR
also demands an account of what it is in virtue of which *x*
and *y* are *causally* related, as opposed to being
merely sequentially ordered (or an account of why mere sequential
ordering is sufficient for causal relatedness). That is, the PSR
applies not only to facts about existence, but also to facts about
relations between existents. (This point will be extremely important
for correctly understanding Spinoza's modal theory in section 2
below.) The PSR asks not only for an explanation of the fact that
*x* causes *y* in terms of prior first-order causes, but
also for an explanation of why there is a *causal* relation of
dependence between *x* and *y* and why it is not some
other kind of relation. As it would not get us very far to answer by
appealing to yet further first-order causal relations, the PSR is
really demanding an account of causation itself. Causation, if the PSR
is true, cannot be a primitive metaphysical relation. So, to echo a
question that lingers today, just what is causation? (For more on the
contemporary discussion, see the entry on the
 metaphysics of causation.
 For more on the PSR and causation, see Della Rocca (2010)).



Unsurprisingly, Spinoza does not treat causation as a metaphysical
primitive. Instead, he provides an account of causation in terms of
something else. In Id1, Spinoza defines self-causation (*causa
sui*) as "that whose essence involves existence or
[*sive*] that whose nature cannot be conceived except as
existing." (Spinoza's *sive* should not be read in
a disjunctive sense, nor is it usually stating a mere equivalence.
What follows the "or" is often a fuller account of what
precedes it. Think of it as an "or better yet...")
Expanding his definition to cover causation in general,
Spinoza's idea is that causation is a matter of
"involvement" or conceptual connection. If *x*
causes *y*, this fact obtains in virtue of a conceptual
connection between the concept of *x* and the concept of
 *y*.[3]
 Spinoza frequently suggests that the *conceiving through*
relation is the paradigm of explanation (e.g., Ia5, IIp5, IIp7s). If
so, then we can understand why Spinoza thinks causes serve as
sufficient explanatory reasons for facts about existence. If causal
relations are conceptual relations, and if conceptual relations are
paradigms of explanation, then to give an account of an object's
existence in terms of its causes is to explain the fact that it exists
in just the way the PSR demands.



Let us apply this point to the case of substances. Spinoza reasons
that existing substances exist in virtue of having causes that bring
about and explain their existence, and non-existing substances do not
exist in virtue of causes that prevent their existence and explain
their non-existence (Ip14). According to Spinoza's account of
causation, this means that existing substances exist in virtue of
conceptual relations to whatever explains their existence, and,
similarly, conceptual relations explain the non-existence of
non-existing substances. What causes or explains the existence or
non-existence of a substance?



Spinoza argues that substances are conceptually, and hence causally,
isolated from one another (Ip2-Ip5). He infers from this that
substances cannot be caused to exist or be prevented from existing by
any other substance (Ip6). But since all existing substances must
nonetheless have causes and reasons for their existence, the fact that
a substance exists must be explained entirely by the substance itself.
That is, all existing substances must be self-caused and hence
self-explained (Ip7). For parallel reasons, the non-existence of a
non-existing substance must be explained solely through facts about
the non-existing substance. The concepts of non-existing substances
must include the explanation for their own non-existence. What about
the concept of a non-existing substance could explain that
substance's non-existence? Spinoza's answer: a
self-contradiction. Non-existing substances do not exist for the same
reason that squared circles do not exist in Euclidean space: they are
conceptually impossible (Ip11d). From the fact of non-existence plus
the PSR, Spinoza concludes that non-existing substances do not exist
because it is impossible for them to exist. They cannot cause
themselves to exist because their very concepts contain a
contradiction, and facts about causation track facts about conceptual
involvement and explanation.



So, returning to our opening questions, could there have been more
substances than there in fact are? Spinoza's answer is
"no," which means that there are no *merely
possible* substances. A substance either exists or its existence
is impossible. Could an existing substance have failed to exist?
Again, Spinoza's answer is "no," since the only
available explanatory basis for its possible non-existence would be
facts about the substance itself. But if an existing substance is
completely causally isolated, what could bring about its
non-existence? Only itself, Spinoza answers, which would amount
to the concept of that substance containing an internal contradiction
that would prevent such a substance from existing in the first place
(Ip7). Spinoza even denies that a substance could exist for a
certain length of time and then go out of existence, since that
would imply that it caused its own self-destruction, a violation
of Spinoza's doctrine that "No thing can be destroyed
except through an external cause" (IIIp4). In reaching all of
these conclusions, Spinoza relies on the self-explaining or
self-causing nature of substances and the explanatory demands of the
PSR. Spinoza concludes that for any existing substance, it could not
have failed to exist nor can it cease to exist. Hence, if a substance
exists, it necessarily exists (Ip7d). On the other hand, if a
substance does not exist, its existence is impossible. Combining these
conclusions, we reach (1): every possible substance necessarily
exists.



Here is a sketch of the main steps of this argument:


3. There must be a sufficient reason why each existing substance
exists and a sufficient reason why non-existing substances do not
exist [PSR; see Ip11d].
4. Causes provide necessary and sufficient reasons for the existence
and non-existence of substances [nature of causation and PSR; see
Ip11d].
5. Substances are causally isolated [Ip6].
6. If a substance exists, it is self-caused [3-5; see
Ip7].
7. If a substance is self-caused, its existence is necessary [nature
of necessity and self-causation; see Ip7d and Id1].
8. If a substance exists, it necessarily exists [6-7].
9. If a substance does not exist, its non-existence is explained
entirely by facts about the concept of its nature [3-5 and
nature of causation; see Ip11d].
10. If facts about the concept of a thing's nature entirely
explains its non-existence, then the concept of its nature contains a
contradiction [nature of concepts and explanation; see Ip11d].
11. If a substance does not exist, then the concept of its nature
contains a contradiction [9-10].
12. If the concept of a thing's nature contains a contradiction,
then its existence is not possible [intuition; see Ip11d].
13. If a substance does not exist, then its existence is not possible
[11-12]


1. Therefore, every possible substance necessarily exists [8 and
13].



The second major stage of Spinoza's argument is to prove that
God is the only possible substance. We will not here rehearse all the
details of Spinoza's argument to this conclusion (for
two discussions, see Lin 2007 and Della Rocca 2001). Like his
argument for (1), Spinoza's argument for (2) relies on the PSR.
Here is one sketch of Spinoza's overall argument for (2):


14. At least one substance
 exists.[4]
15. The concept of God is the concept of the most real substance with
the most power and greatest reason for existing [Id6, Ip9, and
Ip11d].
16. The concept of God is internally consistent [assumption].
17. It would be inexplicable if the internally consistent concept of
the most real substance with the most power and greatest reason for
existing was not instantiated while the concept of a substance with
less power and less reason for existing was instantiated [Ip11d].
18. Nothing is inexplicable [PSR].
19. Therefore, the concept of God is instantiated [14-18].
20. Therefore, God necessarily exists [1 and 19].
21. The existence of God and the existence of other substances are not
compossible [20 and Ip5].


2. Therefore, God is the only possible substance [20-21].



Of these steps, premise (16) is the one for which Spinoza offers the
least explicit justification:



> 
> Since, then, there can be, outside the divine nature, no reason or
> cause which takes away the divine existence, the reason [for its
> non-existence] will necessarily have to be in his nature itself, if
> indeed he does not exist. That is, his nature would involve a
> contradiction. *But it is absurd to affirm this of a Being
> absolutely infinite and supremely perfect* (Ip11d, emphasis mine).
> 



The absurdity Spinoza points to is actually the absurdity of the
non-existence of a being *according to whose concept* it is
infinite and supremely perfect. But why accept that the concept of
Spinoza's God is internally consistent? If Spinoza fails to
justify this assumption, his ontological argument would fall victim to
Leibniz's complaint that even if otherwise successful,
(pre-Leibnizian) ontological arguments prove only a hypothetical
truth: *if* God is a possible substance, then God necessarily
exists. Spinoza's argument, absent a justification of (16),
fails to establish the possibility of God before asserting the
necessity of God's existence.



Even worse, Spinoza faces an especially thorny problem in justifying
(16). For his account of the concept of God in (15) relies on
commitments that even those friendly to theism, such as Descartes,
would reject. Spinoza defines God in Id6 as "a substance
consisting of an infinity of attributes, of which each one expresses
an eternal and infinite essence." Spinoza claims in Ip9, without
any explicit argument, "The more reality or being each thing
[*unaquaeque res*] has, the more attributes belong to
it." This definition of God and the supporting principle in Ip9
were highly controversial. According to Descartes, a substance cannot
have more than one (principal)
 attribute.[5]
 To say that the concept of God is the concept of a substance with
multiple (principal) attributes is, in fact, to appeal to an
internally inconsistent concept. So, the objection runs, not only has
Spinoza failed to justify (16), but (15) is outright false.



Spinoza's defense of (15) would likely be to appeal to the
self-containment of each attribute (Della Rocca 2001). Like substance,
each attribute is a wholly self-contained and self-sufficient way of
conceiving substance (Ip10). Given such rigid containment, Spinoza
would press, how could the fact that a substance has one attribute
preclude that substance from having additional attributes? If there
are no explanatory or conceptual relations between the attribute of
thought and the attribute of extension, the fact that a substance is
thinking cannot explain why that substance could not also be extended.
The lack of a reason for *excluding* an attribute is part of
Spinoza's reason for *including* all possible attributes
as attributes of God. However, even if he can defend the rigid
self-containment of attributes, Spinoza will also need a positive
reason for including them all together as attributes of a single
substance.



This brings us back to Ip9 and the other objectionable aspect of (16).
Why should perfection or reality and strength of reason to exist
correspond to possessing a greater number of attributes? Spinoza does
not offer any explicit defense of this correlation. The demonstration
of Ip9 simply refers readers back to the definition of an attribute
(see also Ep9). Here is one possible way Spinoza might motivate the
correlation between number of attributes and perfection / reason for
existing. The principle in Ip9 may be that to the extent to which a
*single thing* [*unaquaeque res*] can be expressed by a
greater number of attributes, to that extent it is more perfect, and
hence is more real (IId6) and has greater reason for existing (Ip11s).
Spinoza's emphatic "unaquaeque" may point to the
idea that perfection involves *both* unity and diversity. To
the degree to which one and the same thing can sustain a greater
variety of expressions of it, to that extent it is more perfect. The
maximal perfection and reality of God, on this account, is partly
constituted by the fact that God's self-identity is compatible
with a plentitude of incommensurable expressions - infinitely
many attributes - of it. This view of metaphysical perfection,
one which tries to maximize both identity and diversity, is very
similar to Leibniz's account of perfection as *harmony*,
a principle that Leibniz explains as "diversity compensated by
 identity."[6]
 On this reading, God's metaphysical perfection for Spinoza is
the perfection of Leibniz's most harmonious world, the
perfection of maintaining both the one *and* the many (Newlands
2018).



Whether or not Spinoza fully succeeds in defending the consistency of
his concept of God, the striking modal conclusion he draws from it is
clear: "Except God, no substance can be or be conceived"
(Ip14). This statement captures Spinoza's substance monism and
his substance necessitarianism: there is only one possible substance,
God, and that substance necessarily exists.


### 1.2 Modes



Immediately after wrapping up his proof for substance monism in Ip14,
Spinoza claims in the next proposition that "Whatever is, is in
God, and nothing can be or be conceived without God" (Ip15). By
the definition of a mode in Id5, Ip15 implies that everything that
exists other than God is a mode or affection of God. To understand the
import of this claim, it is important to understand what a mode is and
what is it for a mode to be *in* a substance, for Spinoza.



A natural way to think about modes is as a certain kind of property.
The circular shape of the coin is a *mode* of that coin. On
this reading, being circular is a state of the coin, a particularized
way that the coin is. Spinoza's claim that modes are
"in" their substances also suggests that modes
*inhere* in substances akin to the way that properties inhere
in things, and that modes are therefore predicable of substances as
subjects of predication. Circularity, we might say, inheres in the
coin and *the coin is circular*. Of course, there is an
extremely wide range of views about properties and property-bearers
(see the entry on
 properties),
 so claiming that modes are akin to properties that inhere in
substances will not answer all questions. But even putting aside
questions about inherence, property instantiation, and predication
relations, it may seem like Spinoza has made a colossal blunder in
Ip15. After all, how can a table or human being be anything like a
*property*? How can I inhere in something else? What sense
would it make to say of something -- a substance -- that it
is *Sam Newlandsish* in the same sense in which I say of it
that it is round? If there is such a thing as a "category
mistake," this may seem like an especially clear case of
 one.[7]



It would be disappointing if this objection simply assumed from the
outset that (a) objects like tables and human beings are substances
and (b) substances neither inhere in nor are predicable of other
substances. Spinoza agrees with (b), but he has already argued
*pace* (a) that there can be only one substance. It would be
unfair to grant him that conclusion in Ip14 and then insist upon
reading Ip15 that other things still ought to have all the features of
substances. (Of course, these intuitive concerns may well provide
reasons to reconsider Spinoza's arguments for Ip14.)



Interpreters have tried to make sense of Spinoza's
identification of everyday objects with modes without presupposing the
denial of his substance monism. One strategy would be to deny that
Spinoza intends anything like property, inherence and predication by
his identification of everyday objects with modes of God. On this
interpretation, Spinoza's claims about modes and
"in" in Ip15 are really just claims about the
*causal* dependence of all things on God (Curley 1969).
Everyday objects inhere in God in the sense that they depend causally
on God. When Spinoza claims, "Whatever is, is in God," he
really means only that everything is causally dependent on God, a
fantastically unremarkable claim in the 17th century.
Indeed, as others have objected (Bennett 1991, Carriero 1995, Melamed
2009), this proposal makes Spinoza's claim in Ip15 *so*
unremarkable that it is hard to see why Spinoza went to such
obfuscating lengths to phrase his ontology in terms of modes and
inherence in the first place, since he had the categories of efficient
causation and dependent beings at his disposal. 



A different strategy (Carriero 1995) preserves the inherence link
between modes and properties, but understands Spinoza's modes as
particularized accidents or, in contemporary terms, *tropes*
(see the entry on
 tropes).
 According to this reading, collections of particularized properties
constitute everyday objects for Spinoza. Although such bundles of
tropes inhere in substance, they are not predicable of substance.
Hence, although I inhere in substance, it is not the case that
*substance is Sam Newlandsish*, whatever that may mean. Whereas
the first interpretation explained inherence as nothing but efficient
causation, this reading tries to keep causation and inherence
intensionally (though perhaps not extensionally) distinct metaphysical
dependence relations.



Another, more circuitous option begins with a functional account of
modes in Spinoza's ontology. The function of modes, according to
passages like Ip25c, is to provide ways of expressing or conceiving
the power of substance. Perhaps Spinoza actually provides an
*analysis* of inherence in terms of this expressive or
conceptual relation, similar to the way in which he provides an
analysis of causation in terms of conceptual connection. Consider, for
instance, Id3, in which Spinoza defines substance as that which is
"[a] in itself and [b] is conceived through itself, that is, [c]
that whose concept does not require the concept of another thing from
which it must be formed" (the brackets are mine). Instead of
leaving inherence as an unprincipled primitive relation of
metaphysical dependence (*pace* the PSR), one could read [c] as
providing an analysis of *both* [a] and [b]. One thing inheres
in another in virtue of being conceived through it, which, like
causation, is a matter of conceptual involvement. That everyday
objects are modes inhering in and predicated of substance is
extensionally *and* intensionally equivalent to everyday
objects being conceived through substance. Whereas Curley's
interpretation took *causation* to be Spinoza's
underlying account of inherence, this interpretation takes
*conceptual involvement* to be Spinoza's underlying
account of both inherence and causation (for defense, see Newlands
2010a; for dissents, see DiPoppa 2013, Melamed 2012 and Laerke
2011).



Although we will not try to settle this debate here, different
interpretations of Spinoza's category of modes will yield
different accounts of his views on the necessity of modes. For
purposes of ease and neutrality, we will frequently refer to modes as
"objects," which are intended to be a neutral placeholder
for "whatever else exists besides substance."


#### 1.2.1 The Modality of Modes: An Overview



Earlier, it was noted that Spinoza thinks infinitely many
non-substantial objects exist: "From the necessity of the divine
nature there must follow infinitely many things in infinitely many
ways, i.e., everything which can fall under an infinite
intellect" (Ip16). Although Spinoza means more by
"infinite" than simply "exhaustive," he
clearly intends "exhaustive" as well. How many objects are
there? "As many as there can be together" is
Spinoza's basic reply. That is, Spinoza endorses a principle of
ontological plenitude (POP), according to which the greatest number of
compossible non-substantial objects actually exists. Part of
Spinoza's motivation for POP may derive from the PSR itself,
since if the actual world were sub-maximal, non-existing but
intrinsically possible objects would have no reason for not existing,
which would be a brute fact. Perhaps it would also be an undesirable
brute fact if (*per impossibile*) a maximal world with fewer
objects than the actual world existed; what would explain God's
realization of a smaller maximal collection when a larger maximal
collection is possible (see Ip33s2)? In any case, Spinoza's POP
implies that the number of existing objects is necessarily fixed.



Although this is already quite a strong conclusion, it does not yet
rise to the level of full-blown necessitarianism with respect to
modes. There are still at least three possible sources of contingency
for the maximally full world of modes, each of which would be
compatible with POP. Alternative possibility 1 (AP1): There could have
been a different collection of modes, equal in size to the actually
existing collection, but with *entirely* different members.
Alternative possibility 2 (AP2): For some proper subset of the
collection of actually existing modes, there could have been a
different, equinumerous proper subset of modes instead. Alternative
possibility 3 (AP3): One or more of the actual modes could have had
different characteristics than it in fact has.



To illustrate, let the collection of shirts hanging in my closet stand
for the collection of modes. Suppose that my closet could not contain
more or fewer shirts than it currently contains-- my closet is as
full as it can get and I'm the sort of person who could never
have fewer shirts than the most that can all fit in there together.
Still, couldn't I have had an entirely different but
equinumerous collection of shirts (AP1)? Or, keeping some of the
shirts fixed, couldn't I have had a modest blue shirt instead of
the orange plaid shirt sitting there in the middle (AP2)? Or, keeping
all the shirts in the closet fixed, couldn't the orange plaid
shirt have had a single pocket instead of having the two pockets that
it actually has (AP3)?



Necessitarianism requires not only the necessity of the
*number* of existents; it demands the necessity of each member
and the necessity of all of its characteristics. Hence, even given POP
and Ip16, it remains an open question whether Spinoza wants to deny
that there are any alternative possibilities for modes. Am I really
stuck with the exact shirts I've got, double-pocketed orange
plaid and all?



To understand why Spinoza might be attracted to mode necessitarianism,
we need to consider a few additional details of his ontology of modes.
I have been lumping modes together into a single ontological category:
everything that is not a substance. But Spinoza sometimes
distinguishes between two types of modes, infinite modes and finite
modes. Unfortunately, Spinoza gives only a very sparse account of
infinite modes in the *Ethics*, and he makes very few explicit
textual references to them outside the
 *Ethics*.[8]
 When Georg Schuller wrote to Spinoza to ask him for examples of these
curious entities, Spinoza replied with obscure gems like "the
face of the whole universe" and "absolutely infinite
intellect" (Ep64). If the best elucidation of
a philosophical doctrine makes reference to "the face of
the whole universe," that may be a good sign that the doctrine
needs further development. Unfortunately for Spinoza's readers,
infinite modes appear to do some significant work in his metaphysics,
so they cannot simply be ignored if one wants to understand
Spinoza's modal commitments.


#### 1.2.2 Infinite modes



The most salient feature of infinite modes is that they are more
directly related to substance than finite modes are. Spinoza claims
that infinite modes follow more or less directly from "the
absolute nature of any of God's attributes," whereas
finite modes do not follow from the absolute nature of God's
attributes (see Ip21-22 and Ip28d). According to some
interpreters, understanding this distinction is the key to
understanding whether or not Spinoza was a full-blown
necessitarian.



At first glance, Spinoza's picture seems clear enough. (We will
continue to ignore the complicating role of attributes.) Some modes
follow directly from the absolute nature of substance. Interpreters
frequently call these *immediate* infinite modes (Ip21). Other
modes follow directly from those immediate infinite modes. These are
commonly called *mediate* infinite modes (Ip22). There is then
a gap of some kind, and on the other side of the gap is the maximally
full collection of finite modes. Unlike the infinite modes, particular
finite modes do not follow, either directly or indirectly, from the
absolute nature of substance.



The distinction between infinite and finite modes is relevant for
Spinoza's views on modality because of what he says about the
modal status of infinite modes. Spinoza reasons that if an object
necessarily follows from something that necessarily exists, then that
object also necessarily exists (Ip21). This sounds similar to a
familiar and widely accepted modal distribution axiom: \((\Box p \amp
\Box(p \to q)) \to \Box q\). According to this reasoning, if God
necessarily exists, and if the existence of a mode follows necessarily
from the existence and nature of God, then that mode necessarily
exists too. Of course, we need not and should not interpret
Spinoza's following-from relation as the strict logical
entailment of contemporary modal logic. The main point is that
necessity transfers down the following-from chain, according to
Spinoza. If *x* necessarily exists and if *y*
necessarily follows from *x*, then *y* necessarily
exists too. For ease, one may call this the *modal transfer
principle*. (Later, we will try to gain a better understanding of
exactly why Spinoza thinks the modal transfer principle works.)



Notice that *both* conjuncts of the modal transfer principle
must be satisfied for it to apply. That is, for the modal transfer
principle to apply to some *y*, it must be the case that both
(i) *y* follows necessarily from *x* and (ii) *x*
exists necessarily. Hence, if God exists necessarily and if the
existence of Bruce Springsteen follows necessarily from God's
existence, then Springsteen exists necessarily too. Whatever
differences there may be between a thing that exists necessarily in
virtue of its own nature and a thing that exists necessarily in virtue
of following from something else that exists necessarily, that
distinction is wholly *internal* to necessity. Differences
between external and internal sources of necessity, a difference to
which Spinoza sometimes draws attention (Ip33s), does not entail
differences in *type* of necessity or even *strength* of
necessity, and Spinoza nowhere says that it does.



Spinoza's modal transfer principle appeals to the relation of
following-from. To a contemporary reader, this might sound like a
relation of logical entailment, but Spinoza clearly understands it to
be some kind of causal relation (e.g., Ip16c, Ip28d). This means that
Spinoza's following-from relation shares the features of his
causal relations, including the fact that causal relations involve
necessary connections between relata (Ia3). That is, if *y*
follows from *x*, then *y* necessarily follows from
*x*. Furthermore, Spinoza claims that *every* mode
follows from something else (Ip16 and Ip36). Therefore, every mode
necessarily follows from something else, in which case condition (i)
of the modal transfer principle is satisfied for every mode. This does
not yet entail necessitarianism, however, for we still need to
determine whether condition (ii) is universally satisfied as well.
Each mode necessarily follows from something else, but does what it
follows from exist necessarily?



In the case of existing *infinite* modes, Spinoza's
answer is clearly affirmative. In Ip22, Spinoza claims that so-called
"immediate" infinite modes follow from something that
exists necessarily, namely substance. Therefore, by the modal transfer
principle, every existing immediate infinite mode exists necessarily.
Furthermore, Spinoza claims that every so-called "mediate"
infinite mode follows from something that exists necessarily (namely,
an immediate infinite mode), so every mediate infinite mode exists
necessarily as well (Ip23). In short, because there is a chain of
necessary dependence stretching from substance to every existing
infinite mode, every existing infinite mode exists necessarily.



Once again, even this strong modal conclusion is not equivalent to
full-blown necessitarianism regarding infinite modes. Even if every
*existing* infinite mode necessarily exists, could there have
been other infinite modes as well? While there may not be any texts in
which Spinoza explicitly rules this out, it is easy to imagine what he
would say. Non-actual infinite modes do not exist necessarily, or else
they would actually exist, on the plausible assumption that necessity
entails actuality \((\Box p \to p).\) So, for reductio, consider a
non-actual possible world, \(w^\*\), that contains
*Sophia*, one of these extra, non-actual infinite modes. What
is the manner of Sophia's dependence on substance?
Spinoza's discussion of infinite modes suggests that Sophia
must, by definition, follow from God's absolute nature (either
immediately or mediately). If so, then Sophia follows from the
absolute nature of God in \(w^\*\), on the assumption that true
definitions express necessary truths. But in that case, the modal
transfer principle will apply to Sophia in \(w^\*\), in which case
Sophia's existence is necessary. However, again assuming that
necessity entails actuality, Sophia would be actual, pace our initial
assumption. QED.



Of course, that reasoning relies on possible world semantics and some
loaded (though plausible) theses about relations between possible
worlds. Perhaps Spinoza could reach a similar conclusion without
recourse to all that. Spinoza could instead appeal back to his
plentitude principle and its basis in the PSR. If there could have
been more infinite modes than there in fact are, these non-actual,
merely possible modes must be compossible with the collection of
necessarily existing infinite modes. (Another plausible assumption,
expressed loosely: if something is not compossible with what
necessarily exists, then its existence is not possible.) But if there
were non-actual infinite modes that were compossible with the
collection of necessarily existing infinite modes, what could explain
their non-existence? Unless an answer can be given, Spinoza will infer
falsity from a violation of the PSR. We again reach the conclusion of
necessitarianism with respect to every infinite mode. Like substance,
every possible infinite mode necessarily
 exists.[9]


#### 1.2.3 Finite modes: A first pass



Infinite modes exist necessarily because they follow necessarily from
something that exists necessarily, namely God. What about finite
things like furniture and people? This much seems clear: *if* a
finite mode follows from an infinite mode or from substance itself,
then by the modal transfer principle, it exists necessarily too. But
does any finite mode follow from an infinite mode or from substance?
This is where the aforementioned "gap" between infinite
and finite modes becomes modally significant. Consider what Spinoza
says in the lengthy and important demonstration of Ip28:



> 
> 
> Whatever has been determined to exist and produce an effect has been
> so determined by God (by Ip26 and Ip24c). But what is finite and has a
> determinate existence could not have been produced by the absolute
> nature of an attribute of God; for whatever follows from the absolute
> nature of an attribute of God is eternal and infinite (Ip21). It had,
> therefore, to follow either from God or from an attribute of God
> insofar as it is considered to be affected by some mode....But it
> also could not follow from God, or from an attribute of God, insofar
> as it is affected by a mode which is eternal and infinite (by Ip22).
> It had, therefore, to follow from or be determined to exist and
> produce an effect by God insofar as it is modified by a mode which is
> finite and has a determinate existence...and in turn, this cause
> or mode...had also to be determined by another which is also
> finite and has a determinate existence; and again...and so always
> (by the same reasoning) to infinity.
> 
> 
> 



On a cursory reading of this passage, Spinoza seems to say that no
finite mode follows from either an infinite mode or from "the
absolute nature of an attribute of God," lest that mode be
"eternal and infinite," pace the nature of finite modes.
If so, then perhaps Spinoza's point in this passage is that
particular finite modes, like the desk, follow from *only*
other particular finite modes, such as a pile of wood, which
themselves follow from only other finite modes, such as some trees,
and so
 on.[10]
 If so, then it appears that finite modes do not follow from anything
that exists necessarily, in which case the modal transfer principle
will not apply. Absent some other source of necessity for finite
modes, it follows that Spinoza is not a necessitarian.



Suppose, however, that the causal history of the desk is traced all
the way back to the very beginning of the world. Surely the starting
point of the universe -- that from which all the subsequent
objects and events necessarily follow -- surely the initial mode
follows from God's nature or from one of God's infinite
modes. If so, then by the modal transfer principle, the first finite
mode will exist necessarily, and so everything that follows from it,
including the desk, will exist necessarily too.



Spinoza rejects this reasoning. He has little sympathy with the
traditional monotheistic idea that God created the world *ex
nihilo,* and he denies that there is a true "in the
beginning" style cosmogony. In the quotation from Ip28 above,
Spinoza denies that the series of finite modes has an initial starting
point. Spinoza thinks that the series of finite objects extends
backwards in time in an infinitely long causal chain that contains no
initial state. For every finite cause of the desk, there will always
be a temporally prior finite cause of that cause. And a prior cause
of the cause of that cause. And so on, *ad infinitum*. Prima
facie, there is no PSR violation with this picture. For every
particular finite object, there is a sufficient reason for its
existence and characteristics in terms of its prior finite
causes. Each finite object follows from and is thus explained by the
prior state of the world, whose constituents are also explained by a
prior state. If that is all Spinoza intended to say about the modal
status of finite things, then one could read his fiery denials of
contingency as defenses of mere causal determinism and not full-blown
necessitarianism.


#### 1.2.4 The problem of the gap



An important lesson from the previous section is that if there is a
causal gap between finite modes and infinite modes, then
Spinoza's modal transfer principle will not apply to finite
modes, since condition (ii) will remain unsatisfied in each case.
Finite things will be causally determined solely by other finite
things, none of which exist necessarily.



However tempting, this picture has trouble making sense of
Spinoza's repeated claims that everything is caused *by
God* (Ip25-26), a claim Spinoza repeats in the very first
sentence of Ip28d itself. Spinoza frequently emphasizes that
God's power or essence is the cause and explanation of
everything that exists (Ip16, 17, 29s, 33, IAppendix). But if finite
modes follow only from other finite modes, then it seems that they do
not follow from God or substance, which violates one of the
most basic features of modes, namely their dependence, qua modes, on
substance (Id5).



This is a notoriously difficult question facing Spinoza's
metaphysics, one that was raised by Leibniz just a year after
Spinoza's death (Leibniz 1969, 203). Sometimes this worry was
historically expressed as whether Spinoza can "derive" the
finite from the infinite, but it is not really a question of logical
deduction (Hubner 2014). The issue is whether Spinoza can
consistently maintain that God is the cause of all things and that
finite things follow only from other finite things.



One possible response would appeal to the close relationship between
finite modes and the power of God. Spinoza sometimes describes finite
modes as limited expressions of God's own power (Ip36d; IVp4d),
in which case perhaps being caused by other finite modes is a way
of being determined by God's power. The success of this response
depends on the relationship between God and God's modes for
Spinoza, an interpretive point that is also heavily disputed. This
reply would not work, for instance, if the fundamental connection
between substance and modes is purely causal.



Curley has proposed a more elaborate and elegant solution for
reconciling Ip28 and the claim that all modes follow from substance
without positing any closer relationship between God and finite modes.
(This is understandable since Curley is the leading advocate of the
"causal only" interpretation of how modes depend on
substance.) Curley suggests that Spinoza's finite modes are only
*partially* determined by other finite modes (Curley 1969).
They are also partially determined by infinite modes, which Curley
understands to be general features of the world described by the laws
of nature. The desk follows partly from infinite modes and partly from
other particular finite modes.



In more contemporary terms, Curley's proposal is that every
state of the world is determined by the laws of nature plus the prior
state of the world. The laws of nature and the antecedent state each
contribute to bringing about the desk, but neither is sufficient on
its own. This division of labor would allow Spinoza to overcome the
problem of the gap without violating Ip28. Particular finite modes do
follow partly from God's nature, in virtue of following partly
from infinite modes - but only partly. They also follow partly
from other finite modes. Admittedly, Spinoza does not say in Ip28 that
finite modes follow only *partially* from other finite modes,
but neither does he explicitly say that finite modes follow
*entirely* from other finite modes.



If Curley is correct, then because finite modes are only
*partially* determined by infinite modes, the modal transfer
principle will not apply to finite modes. (One assumption here is that
condition (i) requires following from *entirely*.) This blocks
necessitarianism, since no finite mode would follow entirely from
something that exists necessarily. Thus, Curley's interpretation
concludes, particular finite modes do not exist necessarily, despite
(partly) following from God's nature. Hence full-blown
necessitarianism with respect to finite modes is false and AP1, AP2,
and AP3 represent genuine alternative possibilities for Spinoza. This
finds support in passages like IIa1:



> 
> The essence of man does not involve necessary existence, that is, from
> the order of Nature it can happen equally that this or that man does
> exist or that he does not exist.
> 



Although the first half of that statement is thoroughly traditional,
Spinoza's claim that the order of Nature leaves the existence or
non-existence of particular finite things undetermined seems to posit
genuine contingency in the world. (In IIp10d, Spinoza cites IIa1 and
claims that it would be "absurd" to conclude that a
particular person exists necessarily, though it is unclear whether the
absurdity lies in the modal conclusion itself or in the reasoning
about finite essences that would lead to the modal conclusion.)



As for those passages in which Spinoza seems to profess full-blown
necessitarianism (i.e., Ip16, 17, 29, 33, IAppendix), his appeals to
necessity could be ambiguous between a strong form of determinism and
full-blown necessitarianism. Yes, everything finite necessarily
follows from something else and so everything finite is
"necessary" in the sense of "being fully
determined," but nothing finite follows entirely from something
that necessarily exists, and so no finite mode exists necessarily in
the full-blown sense of that
 term.[11]
 Importantly, Curley defends Spinoza's rejection of
necessitarianism without positing a complete causal gap between finite
modes and God's nature; finite modes do partly follow from God
and God's infinite modes.



However, consider AP1 again, the possibility of an entirely different
collection of finite modes. According to Curley, because no member of
the collection exists necessarily, the collection itself is not
necessary. That is, God could have brought about an entirely different
series of finite modes. If so, what explains why *this* series
of finite modes exists as opposed to one of the alternative possible
series? (The question is not why God *chose* to create this
series of modes rather than another possible series, a question that
animated Leibniz. Spinoza denies that God has a will in the
traditional sense, and so talk about *choosing* one possible
world over another has no place in Spinoza's system (Ip17s and
IIp49c). Nonetheless, the PSR demands a reason in virtue of which God
realizes this series of finite modes rather than another possible
series.)



I noted earlier that Spinoza could explain why a particular finite
mode exists by appealing (in part) to other particular finite modes,
namely its actual causes. But Spinoza could not explain why this
series, as opposed to some other series, exists by appealing to other
particular existing modes. This would be akin to explaining why an
entire series of causes exists by appealing to one of those very
causes. We aren't asking why any particular mode exists, but why
this whole series, and not some other series, exists. Appealing to yet
another contingent fact appears to get us nowhere towards accounting
for the entire set of contingent
 facts.[12]



Nor could Spinoza appeal to substance or infinite modes to explain the
entire series of finite modes, for two reasons. First, according to
Curley's own account, substance and its infinite modes do not
fully explain or cause any particular finite mode (by Ip28). But as
there seems to be nothing to the collection of finite modes beyond the
individual members themselves, it is unclear how substance and its
infinite modes could fully explain or cause the entire series without
fully causing or explaining any individual member.



Second, if the entire series of finite modes were caused by God or
something that necessarily followed from God, then the entire series
would exist necessarily after all (pace AP1). Remember that causation,
necessary connection, and following-from track each other, according
to Spinoza. So if the entire series of finite modes follows from
something that exists necessarily, then by the modal transfer
principle, the series itself would also exist necessarily. If so, then
there would not be any alternative possible series to the series
of actual finite modes. Furthermore, it is hard to see how Spinoza
could block the transfer of necessity from the series of finite modes
to the individual members of that series, in which case both AP2 and
AP3 would be ruled out as well.



This leaves us with an interpretive dilemma. On the one hand,
Curley's account respects both the demonstration of Ip28 and
Spinoza's frequent claims that all modes follow from God's
nature. A consequence of his account is that Spinoza is not a
full-blown necessitarian. On the other hand, Curley's Spinoza
must reject very natural-sounding demands of the PSR. Spinoza would
have to accept that there is no explanation why this entire series of
finite modes exists rather than another possible series, a point
Curley has conceded (Curley and Walski, 1999).



That concession might seem like too high an interpretive price to pay,
especially since there is no independent reason to think Spinoza
rejects the demands of the PSR when applied to the entire series of
finite modes. It would be nice if Spinoza could accept an unrestricted
version of the PSR and still preserve the claim in Ip28d that
particular finite modes do not follow from infinite modes or the
absolute nature of God without recreating the problematic gap. In the
next section, we'll consider an attempt to do just that. A
consequence of this alternative reading will be that Spinoza endorses
full-blown necessitarianism.


#### 1.2.5 Finite modes: a second pass



Let us return to Spinoza's crucial claim about finite modes in
Ip28. He states that particular finite modes (a) do not follow from
"the absolute nature of an attribute of God," even though
(b) they follow from an attribute of God "insofar as it is
considered to be affected by some mode." (As a reminder: we will
continue to drop the reference to attributes for ease of expression.)
Two questions immediately arise:



(1)
What is the difference between following from the
*absolute* nature of God and merely following from God in the
second, more qualified manner?
(2)
Why should the way a particular thing is *considered* be
relevant for this distinction?


According to one prominent interpretation (Garrett 1991 and 2018), to
follow from the *absolute* nature of God is to follow in an
unqualified, pervasive and permanent manner, as infinite modes do
(Ip21-23). Spinoza denies that finite modes follow in that way.
However, following from God's nature in a more qualified way
does not imply that finite modes do not follow from God at all -
to infer that would be to reintroduce the problem of the gap. Rather,
Garrett contends, Spinoza denies only that any particular finite mode
follows from God's absolute nature *independently of its
relations to other finite objects*. This leaves open the
possibility that although no particular finite mode follows from the
absolute nature of God, the entire collection of finite modes as a
whole follows from the absolute nature of God or from an infinite mode
of God.



Garrett's account presents a five-fold division of
Spinoza's expression "following from God's
nature":


1. The immediate infinite modes follow directly from God's
absolute nature.
2. The mediate infinite modes follow indirectly from God's
absolute nature.
3. The infinite collection of finite modes, considered as a whole,
follows indirectly from God's absolute
 nature.[13]
4. Each particular finite mode, considered in relation to the other
members of the series, follows from God's non-absolute
nature.
5. Each finite mode, considered independently of its relation to the
other members of the series, does not follow from God's
nature.



If we apply Spinoza's modal transfer principle to this division,
the objects described in [i] and [ii] exist necessarily. Similarly,
the necessity of God's nature in [iii] trickles down the
following-from relation, and so even though the series as a whole
follows only indirectly from God, its existence would nonetheless be
necessary, as with mediate infinite modes. 



What about particular finite modes described in [iv]? On
Garrett's proposal, their existence too will be necessary, which
commits Spinoza to full-blown necessitarianism. To see why, notice
that the difference between [iii] and [iv] is not a function of the
presence or absence of the following-from relation itself. The
difference is between following from God's absolute vs.
non-absolute nature, whatever that distinction amounts
to. Spinoza's modal transfer principle is indifferent to
the difference between [iii] and [iv]. The principle is too
coarse-grained to track the absolute/non-absolute distinction; it
tracks only the following-from relation from a necessarily existing
source. Since both conditions of the principle are satisfied in [iv],
necessity is transferred from the entire collection of finite modes to
the individual members themselves. Thus, the desk exists necessarily.
If this is correct, Spinoza can consistently claim that every finite
mode exists necessarily and follows from God's nature *in
some way*, while still maintaining that no particular modes
follows directly or indirectly from the *absolute* nature of
God.



The objects described in [v] do not follow from God's nature at
all, in which case the modal transfer principle will not be satisfied.
Insofar as that is the only available source for their necessity, it
follows that they do not exist necessarily. But what is the difference
between the objects described in [iv] and the objects described in
[v]? In one sense, nothing: they are the same finite modes! That
cannot be the full story, however, lest there be no explanation why
the modes in [iv] follow from the nature of God whereas *those very
same modes* in [v] do not. The only difference between [iv] and
[v] is how a mode is *considered* in each case. (Although
Garrett himself uses this "considered" claim, he does not
say whether he thinks there are any true ways of considering objects
corresponding to [v].)



Hence, if the desk is considered in relation to the entire series of
finite modes, it follows from God's nature and exists
necessarily. Considered independently of that relation -- if such
can be done -- the desk does not follow from God's nature
and does not exist necessarily. This gives rise to a more precise
version of our earlier question:



(2')
Why should the way a particular thing is
*considered* in relation to other particular things be relevant
for whether it follows from God?


And, since that difference also generates a modal difference, we
should also ask:



(3)
Why should the way a thing is considered be relevant for its
modal status?


Answering these questions in the next section will drive us yet deeper
into Spinoza's modal metaphysics. First, however,
Garrett's account faces an independent worry (Curley and Walski
1999, Huenemann 1999). Return to the relationship between [iii] and
[iv]. There is supposed to be a significant difference between the
manner in which the collection of finite modes follows from God *as
a whole* and the manner by which any particular member of that
collection follows from God. However, if the entire collection of
finite modes follows indirectly from God's absolute nature, that
seems to imply that each individual member of the series
also follows from God's absolute nature. Imagine trying to
cover the collection of objects on my desk in coffee without making it
the case that each object on my desk is covered in coffee. This seems
impossible, as there is nothing more to the collection of things on my
desk being covered in coffee than each and every thing on my desk
being covered in coffee. Even worse, it is hard to see how the entire
series of finite modes could have the property *following from
God's absolute nature* if no member of the series has that
property.



The most promising line of response denies that the series of finite
modes is nothing above and beyond its individual members. Following
others, the entirety of finite modes has been described as a
"series" or "collection," a label that
naturally suggests that the properties of the entire collection will
be posterior to and derivative from the properties of its individual
members. Spinoza himself rarely refers to just the collection of
finite modes with a single expression, though he sometimes includes
them in his locution "the order of nature" and he
describes them as a "series" twice, both outside the
*Ethics* (C I/41 and C I/307). Regardless of the terminology,
one could contend that the whole series is more than just the sum of
its the members. Spinoza does sometimes suggest that wholes can be
prior to their parts (Ep32, IIp13le7s), though other times he suggests
that parts are always prior to wholes (Ip15). Whether the series of
finite modes is more holist or atomistic, and whether, on a holist
mereological account, one of the non-supervening properties of the
whole series is *following from God's absolute nature*,
are still open interpretive questions. The soundness of this reply
will likely turn on whether or not the collection of finite modes is
itself an infinite mode, a point about which interpreters continue to
disagree.


## 2. The Nature of Modality



We have now seen two competing accounts of Spinoza's views about
the modal status of finite objects. Some argue that Spinoza endorses a
strong form of determinism that falls short of full-blown
necessitarianism. On this reading, finite modes do not exist
necessarily and there are alternative possibilities to the series of
actual finite modes that God did not bring about. Others have argued
that Spinoza's account of the relationship between God and
finite modes readily accommodates full-blown necessitarianism and
that, given the large number of passages in which Spinoza appears to
affirm necessitarianism without qualification, there is
sufficient evidence that Spinoza intentionally endorsed
full-blown necessitarianism.



Like almost all discussions of Spinoza's modal commitments, this
dispute focus on the *distribution* of modal properties: which
things exist necessarily? Far less attention has been given to
Spinoza's account of the *nature* of modality. This
section discusses whether Spinoza has an account of modality itself,
and if so, what light that account sheds on the dispute over his
alleged necessitarianism.



Spinoza is emphatic that particular modal ascriptions have reasons
behind them: "A thing is called necessary either by reason of
its essence or by reason of its cause" (Ip33s1). But we
can also consider a higher-order question: for what
reason(s) do modal ascriptions work in the way that Spinoza claims
they do? For ease, let us focus on modal *properties* instead
of modal ascriptions. The question is similar to the one raised
earlier about causation. What explains causation itself? Arguably,
Spinoza's answer is that causal relations obtain in virtue of
conceptual connections between causal relata. A parallel question can
be raised about modality itself. Do basic modal properties obtain in
virtue of other, non-modal properties or is modality primitive for
Spinoza?



Given Spinoza's embrace of the PSR and his efforts to explain
other dependence relations (such as causation and, perhaps,
inherence), it would be surprising and disappointing if modality got a
free explanatory pass. Of course, we probably should not expect
Spinoza to have anything like a full-blown theory of modality in the
forms that contemporary metaphysicians now provide (for an example,
see the entry on the
 possibilism-actualism debate).
 Only in recent decades have philosophers come to appreciate how
complex and rich the metaphysics of modality is, and Spinoza would be
in good company if he says things that seem, by today's
standards, mostly underdeveloped. Nonetheless, he may have the
beginnings of an account that helps illuminate his other modal
commitments.



A promising place to start is the modal status of God's
existence. In Ip11, Spinoza claims that God necessarily exists. But
what is it in virtue of which God necessarily exists? This might sound
like an odd question. Once explanations reach a necessarily existing
object, are there further *in virtue of* questions to be asked
about that object's existence? More generally, when we reach
necessity, haven't we reached the end of
 explanations?[14]
 Not always: mathematics is full of asymmetrical
explanatory relations among necessarily true propositions.
Similarly, Spinoza thinks that substance causes and asymmetrically
explains necessarily existing infinite modes. Hence Spinoza must
believe that dependence and explanation are more fine-grained
relations than modern logical entailment, since according to the
latter, every necessary proposition entails and is entailed by every
other necessary proposition.



Spinoza explains the necessity of God's existence by appealing
to God's nature. This may sound like a non-answer, but it is
not. Spinoza is not claiming that there are no explanatory grounds for
God's existence; he is claiming that facts about God's
nature explain the modality of God's existence. What about
God's nature explains God's existence? In Ip7 and Ip11,
Spinoza appeals to an involvement relation between the concept of
God's essence and the concept of God's existence. That is,
God exists in virtue of the fact that the concept of God involves the
concept of existence. Spinoza also thinks that the conceptual
involvement relation between God and existence explains the fact that
God *necessarily* exists. In Ip19d, Spinoza writes,



> 
> For God (by Id6) is substance, which (by Ip11) necessarily exists,
> that is (by p7), to whose nature it pertains to exist, or (what is the
> same) from whose definition it follows that he exists.
> 



In Ip7, Spinoza equates "pertaining to its nature to
exist" with "essence necessarily involving
existence" and "causing itself." Self-causation in
turn is explained in Id1 as a "nature that cannot be conceived
except as existing." That is, what explains the necessity of
God's existence is the fact that the very concept of God
involves the concept of existence. He repeats these connections in
Ip24d, "For that whose nature involves existence (considered in
itself) is its own cause, and exists only from the necessity of its
nature." In other words, Spinoza explains necessity in terms of
conceptual connections. Although Spinoza does not develop a richer
account of conceptual relations that Leibniz will later achieve, his
general idea seems to be that conceptual relations are the relations
that explain and ground necessary connections.



Spinoza makes similar appeals to conceptual relations when he invokes
geometrical examples to describe the necessity with which other things
follow from God:



> 
> ...all things have necessarily flowed, or always follow, by the
> same necessity and in the same way as from the nature of a triangle it
> follows...that its three angles are equal to two right angles
> (Ip17s).
> 



Spinoza later identifies this same geometrical relationship with the
conceptual involvement relation (IIp49). What it is for things to
follow from God necessarily is for those things to be (asymmetrically)
conceived through God, whose concept involves (the concept of)
existence. The necessity of God and the necessity of existing things
are both explained by and grounded in conceptual relations. Spinoza
makes this connection emphatic in Ip35, "Whatever we conceive to
be in God's power, necessarily exists."



Conversely, contingency obtains in virtue of the lack of certain
conceptual connections. In the case of contingent existence, an object
exists contingently just in case its concept is neither connected to
the concept of existence nor to something else whose concept is
connected to the concept of existence. Hence if a mode is
conceived in such a way that it is not conceived in relation to
something involving existence, it will exist contingently and not
necessarily (as per Ia7). The point is not just that it would be
*conceived* as contingent. On this account, how a thing is
conceived partly fixes its modal status. In explaining modal features
in terms of an involvement relation between concepts, Spinoza provides
an answer to (3) from the previous section and thereby identifies
himself with a long and distinguished tradition of philosophers who
explain modal facts by appeal to conceptual relations.



This account also explains why Spinoza is attracted to his modal
transfer principle in the first place. Recall that the modal transfer
principle states that necessity transfers along following-from chains
whose nodes include at least one necessarily existing thing. We saw
earlier that Spinoza's following-from relation is a causal
relation and that causal relations are conceptual relations for
Spinoza. But we just saw that necessity is also partly a function of
conceptual relations. Thus necessity transfers along following-from
chains because both necessity and following-from are grounded in the
same relations of conceptual involvement. The underlying conceptual
nature of modality, causation, and following-from explains why
Spinoza's modal transfer principle works.



Another upshot of all this is that modality is not wholly extensional
for Spinoza. The ways in which objects are conceived partly determines
a thing's modal status. In particular, whether a finite mode
exists necessarily or not depends in part on whether it is conceived
through something whose concept involves existence. (For further
discussion, see Newlands 2010b and Newlands 2017.)


### 2.1 Necessitarianism Vindicated



With this analysis in hand, let us return to Garrett's proposed
account of Spinoza's necessitarianism. Garrett claims in [iv]
that each particular mode, conceived in relation to all the other
particular modes, follows from God's nature, and he concludes
that therefore every finite mode exists necessarily. However,
according to [v], the same finite mode conceived independently of the
relation to every other finite modes fails to follow from God and so
fails to exist necessarily. Spinoza's conceptual account of
modality explains why he thought modality works in this particular
way.



Suppose the entire collection of finite modes, considered as a whole,
follows from a necessarily existing infinite mode. Hence, the entire
collection as a whole exists necessarily. In order for a particular
finite mode in that collection to exist necessarily, it must be
conceived as following from something that exists necessarily. How can
a finite mode be conceived as following from something that exists
necessarily? The answer is clear: by being conceived in relation to
the whole collection. That is, when finite modes are considered in
relation to all the other finite modes, the right conceptual
connection obtains and Spinoza's modal transfer principle is
satisfied. This provides an answer to (2') from the previous
section. Whether a mode is considered in relation to the rest of the
series is relevant to its modal status because (a) modal facts are
sensitive to the conceptual relations that the considering relation
picks up on and (b) considering a particular finite mode in relation
to the whole series of finite modes tracks the relevant conceptual
connection that satisfies the modal transfer principle.



Of course, not just any way of considering a finite mode will be
relevant for its modal status. Considered as "the largest piece
of furniture in the office," the desk does not exist
necessarily. By Spinoza's lights, the way of conceiving the desk
needs to involve something that follows from God's nature if the
desk is to exist necessarily. This is why, if Garrett is correct,
considering the desk in relation to the rest of the entire series of
finite objects is relevant for its modal status, whereas considering
the desk in other, less causally relevant or more isolated ways, is
 not.[15]


### 2.2 Non-necessitarianism also vindicated



If particular finite things exist necessarily in virtue of being
considered in relation to the whole series of finite things, two
lingering questions remain:



> 
> (4) Can you and I ever grasp such all-encompassing ways of conceiving
> particular things?
> 



> 
> (5) Are there other, less inclusive ways of considering a finite
> object in virtue of which it does not exist necessarily?
> 



With the respect to (4), Spinoza's answer is unfortunately
negative. Spinoza sometimes describes the mental corollary of these
very inclusive and complete ways of conceiving objects in terms of
*adequacy*, and he is very pessimistic about our ability to
have adequate ideas of particular things (see especially
IIp24-31, though he holds out more hope in Part Five). Spinoza
even links our natural tendencies to represent objects independent of
their infinitely extensive causal networks with their contingency
(IIp31c), just as the above interpretation predicts. So while we can
understand the metaphysical principles which guarantee the necessary
existence of a finite thing insofar as it is conceived in relation to
every other finite thing, we tend to adopt far more limited concepts
of finite things, in virtue of which necessitarianism is false.
Spinoza remains confident that *there is* a complete way of
conceiving a particular finite object in relation to all others, but
it is unlikely that we will ever be able to psychologically grasp such
complete and necessitating concepts. Spinoza's
metaphysics meets his psychology here, and psychology wins.



This is an *unfortunately* negative answer in the light of
Spinoza's ethical theory. As a systematic thinker, Spinoza
thinks metaphysical conclusions about modality have consequences for
ethics. Although pursuing the relations between Spinoza's
metaphysics and ethics are beyond the scope of this entry (see
Newlands 2018), Spinoza clearly thinks that ethically relevant
conclusions follow from his metaphysics of modality. For example, he
writes in Vp6:



> 
> Insofar as the mind understands all things as necessary, it has a
> greater power over the affects, or is less acted on them.
> 



Spinoza thinks we morally improve by gaining power over our passive
affects and becoming more active (Vp4), so our inability to conceive
finite things as related to everything else (and so as existing
necessarily) means our prospects for moral perfection are quite
dim.



With respect to (5), Spinoza suggests that there are more and less
complete ways of genuinely conceiving objects (see, for instance,
Ip24d and IVd3-4). If there are true but incomplete ways of
conceiving objects, Spinoza will occupy the interesting position of
consistently affirming both necessitarianism and its denial, relative
to these different ways of conceiving objects. This pairing sounds
like a contradiction until we appreciate the force of Spinoza's
conceptualist account of modality. If the truth-value of modal
predications is sensitive to ways of conceiving objects (as a modern
day anti-essentialist might agree), and if Spinoza endorses a variety
of modally salient ways of conceiving objects, then he can
consistently affirm both the truth and falsity of full-blown
necessitarianism relative to different ways of conceiving finite
objects.



If this is all correct (a very big "if"!), then Garrett
and Curley's conclusions can both be right, though
neither tells the complete modal story. Something less than full-blown
necessitarianism will be true in virtue of ways of conceiving objects
that do not include their relations to the entire, infinitely large
and complex range of other particular things. At the same time,
full-blown necessitarianism will also be true in virtue of ways of
conceiving finite things that are maximally inclusive with respect to
relations to the rest of the world. This middle ground provides an
answer to Curley's otherwise worrisome objection to the
necessitarian interpretation: "If each particular feature of the
universe, considered in itself, is contingent, then their totality is
also contingent" (Curley 1988,
 49).[16]
 This expansion of contingency from the part to the whole would be
true only if the shift in the ways finite things are conceived did not
sometimes entail a shift in their modal status. Although this is a
very widespread essentialist assumption today, it is a false
one according to this reading of Spinoza's modal theory.
Just as necessitarianism at the most expansive conceptual level does
not jeopardize contingency at narrower levels, so too contingency at
narrower levels need not bleed into the modal status of things
conceived in the most expansive way.


## 3. The Ground of Modality



A final and underexplored topic in Spinoza's modal metaphysics
concerns what we might call the *ground* of modality. There was
a lively dispute in the 17th century about the relationship
between God and modality. Although there was a general consensus that
modal facts - like so much else - depend on God in some
way or other, there was considerable disagreement over exactly how to
understand that dependence. Monotheistic metaphysicians disagreed over
both (a) on what in God modal truths and modal truth-makers depend and
(b) by what manner of dependence modal truths and modal-truth makers
depend on God. The first set of issues concerns the divine
*ground* of modality and the second concerns the *grounding
relation* that modality bears to its ground (for some recent
discussions, see Chignell 2012 and Newlands 2013).



Spinoza cannot accept two of the most prominent accounts proposed by
his contemporaries. According to Descartes, (a) modal truths and modal
truth-makers depend on God's volitions and (b) the form of
dependence is efficient causation. According to Leibniz, (a) modal
truths and modal truth-makers depend on God's ideas and
intellectual activities and (b) the form of dependence is ontological
and does not involve efficient causation. However, Spinoza denies that
God's nature contains a will and intellect in the sense required
for these accounts (Ip17s).



Nonetheless, Spinoza thinks that all things depend on God (Ip15),
and he points to an alternative account of how possibilities depend on
God. He claims that non-existing modes are grounded in God's
actual attributes. "The ideas of singular things, or of modes,
that do not exist must be comprehended God's infinite idea in
the same way as the formal essences of singular things, or modes, are
contained in God's attributes" (IIp8). He unpacks the
"comprehension" or containment of non-divine formal
essences in conceptual terms: "Essences [of non-existing things]
are comprehended in another in such a way that they can be conceived
through it" (Ip8s2). This suggests that the essences of all
things, including non-existing things, are conceptually contained in
God's attributes.



In more general terms, Spinoza's idea seems to be that
possibilities are grounded in God by being actually exemplified by
God, a view that fits nicely with interpretations of Spinoza's
modes as things that inhere in God (see section 1.3 above). Thus, it
is possible for something to be thinking because God is actually a
thinking thing (IIp1d). The grounding of possibility in actuality is a
very attractive metaphysical thesis in its own right, and
Spinoza's God has a sufficiently rich nature to ground all
possibilities by actually exemplifying them all (Ip15 and Ip16).



Spinoza's account of the grounds of modality also presents an
interesting challenge to anyone attracted to the thesis that God
grounds possibilities, but who wants to deny that God directly
exemplifies every possibility (Newlands 2016). Those unhappy with
Spinoza's expansive divine nature would need to explain how it
is that God grounds some possibilities, such as being extended,
without actually being extended. One could follow Descartes in
harkening back to the Scholastic notion of "eminent"
containment, but Spinoza reads that appeal as the name of the problem,
not its solution. Leibniz was sometimes attracted to the idea that
every basic creaturely possibility is formed from God's
non-mental perfections, but he will have a hard time explaining
how every creaturely possibility can be constructed out of the sparse
set of traditional divine perfections.



Without reducing creaturely possibilities to God's actual
perfections (as idealists do with extension), Spinoza presents an
alternative grounding thesis and a challenge. Let every possibility be
grounded in God via actual exemplification, even if this requires
expanding the divine nature beyond its traditional boundaries. For
those unwilling to follow Spinoza on this expansion, Spinoza's
challenge is for proponents of nearby alternatives to provide a
non-metaphorical explanation of how God grounds certain basic
possibilities without actually and directly exemplifying them. Until
such an account is given, Spinoza's biting conclusion offers an
unmet challenge: "But by what divine power could [extension or
any property not exemplified by God] be created? They are completely
ignorant of that. And this shows that they do not understand what they
themselves say" (Ip15s). At the very least, Spinoza's
challenge highlights how his modal metaphysics extends beyond the
topic of necessitarianism and continues to invite wider
investigation.