The Elusiveness of the One and the Many in Spinoza: Substance, Attribute, and Mode
Michael Della Rocca
Different dimensions of idealism, it might be thought, shape Spinoza’s work. Perhaps the most fundamental is the strand of idealism according to which all that exists is somehow dependent on thought.1 Such an idealism, I have argued, is more or less dictated by Spinoza’s commitment to the Principle of Sufficient Reason, a thesis which I unapologetically see as providing the key to much of Spinoza’s thought.2
I should like here, however, to focus on two other strands of idealism or apparent strands that might be found in Spinoza. These possible strands are, as we will see, connected to the fundamental kind of idealism that I just identified, and they are particularly important because they bring to the fore the subtlety and ingenuity of Spinoza’s conception of number and of the alleged difference between the one and the many.
The first of these other strands of idealism concerns the attributes of substance. On this view, contrary to what many interpreters have thought, the attributes are not many but are, rather, the same; there is no distinction among the attributes, no genuine multiplicity. Instead, any distinction here is some kind of illusion, somehow dependent on our minds, and not reflective of any actual differentiation in the substance. This appeal to the mind-dependence of any distinction among the attributes shows that this strand of idealism is in keeping with the general and fundamental view that all things are thought-dependent.
This kind of idealism is found prominently in Hegel’s interpretation of Spinoza and in Hegelian interpreters such as Harold Joachim and other British Idealists.3 This reading is also widely associated with the so-called subjectivist view of the attributes, a view prominently espoused by Harry Wolfson.4 There has been much criticism of the subjectivist view in the literature,5 and this is not surprising for there is substantial, apparent textual evidence against such a reading. I too have taken a ride on this anti-Wolfson bandwagon.6 But here one of my goals is to atone for my unfair objections and to identify what is right (and what is wrong) in Wolfson’s interpretation.
The second particular strand of idealism also turns on an alleged differentiation within substance. Here the apparent differentiation concerns not attributes but modes. On the standard realist, non-idealist view, modes are genuinely different from other modes. On a non-realist, idealist understanding of modes, the distinction among modes is, again, illusory and somehow mind-dependent. This understanding of modes is to be found in the so-called acosmist reading of Spinoza in Maimon and in Hegel and in followers of Hegel among Spinoza commentators. I have already come out in favor of such a reading of Spinoza in various papers.7 Here I will argue for such a reading through new and previously unexplored means.
My general plan in this paper is to identify in a new way the grounds of Spinoza’s views on number, on one-ness and many-ness, and in so doing to offer new support for reading Spinoza as adopting at least some of the strands of idealism that have been attributed to him.
I. Conflicting Texts?
I begin not with attributes or modes, where the debate over idealism and multiplicity has been most intense, but with substance, where there has been somewhat less strife. It’s clear that, in some sense, for Spinoza God is the only substance. After all, Spinoza says explicitly that “God is unique, that is (by E1d6) […] there is only one substance” [E1p14c1].8 Similarly clear statements occur elsewhere both in the Ethics [e.g., E1p10s: “in nature there exists nothing but a unique [unicam] substance”] and in the Short Treatise [e.g., KV, I, ch. ii, §17, note e and KV, II, ch. xxiv, §3].9 This is Spinoza’s famous substance monism and, while there is debate over the characterization of this monism, there is broad agreement that Spinoza is some kind of monist.
However, as Mogens Lærke has helpfully stressed in a recent, excellent paper, Spinoza on at least two occasions evinces hesitation about saying that God is one and that God is the only substance.10 First, in his Cogitata Metaphysica immediately after saying that God is unique and that there cannot be more than one of the same nature as God, Spinoza seems to take it back: “If we wished to examine the matter more accurately, we could perhaps show that God is only improperly called one and unique.”11 Spinoza also says in a letter which is as brief as it is significant both for subsequent philosophy of mathematics and for idealism, “it is certain that he who calls God one or unique has no true idea of God, or is speaking of him only very improperly.”12
These sentiments in Spinoza have long made me uneasy for it has been unclear to me how to incorporate them into a general understanding of Spinoza’s substance monism. Lærke’s paper makes great strides in this connection and enriches the treatment of number and Spinoza’s monism.13 I aim in this chapter to go beyond Lærke’s paper in three ways: (1) I will articulate the philosophical underpinnings of Spinoza’s conception of number at work in the passages I have emphasized; (2) I will demonstrate the significance of these passages not only for Spinoza’s conception of the one-ness of substance, but also for his conception of the many-ness of attributes and of modes; (3) finally, throughout the chapter, I will emphasize the connection between the notion of number and one-ness at work in Spinoza and the understanding of Spinoza as an idealist.
II. Number and Essence
Let’s examine Spinoza’s conception of what it is to number a thing or things—i.e., what it is for us to see them as one or many—before returning to substance (and then going on to discuss attributes and modes). For Spinoza, to number a thing or to number things is to regard the things in question as falling under a certain concept or belonging to a certain kind [genus]. This is evident in a famous passage that was sampled and, in a certain respect, praised by Frege:
We do not conceive things under numbers unless they have first been brought under a common genus [commune genus]. For example, he who holds in his hand a penny and a dollar will not think of the number two unless he can call the penny and the dollar by one and the same name, either “coin” or “piece of money.” For then he can say that he has two coins or two pieces of money, since he calls not only the penny, but also the dollar, by the name “coin” or “piece of money.” From this it is evident that nothing is called one [unam] or unique [unicam] unless another thing has been conceived which (as they say) agrees with it. [Ep. 50/C II 406/G IV 239]14
Why should it be the case that to count—to number—a thing or things is, as Frege would agree, to see them as falling under a certain concept or belonging to a certain kind? To see what is driving Spinoza here, consider what would be the case if we saw a certain thing or certain things as one or many—i.e., we numbered them—but did not see them as falling under a certain concept or belonging to a certain kind and, in particular, if we did not number them in part because they fell under a certain concept or belonged to a certain kind. Without seeing the object or objects in terms of this feature, it seems that our counting just this or these objects would be arbitrary. Why are we focusing on just this object or just these objects (and counting them) unless we see them as belonging to a kind or as having a certain property? Our thought of just these objects would then be unexplained. This would offend against Spinoza’s rationalism—against his rejection of unexplained or arbitrary, brute facts.15 The kind or genus is that in virtue of which we regard certain objects as available to be counted. At work here is a kind of descriptivism in Spinoza’s thought: we do not represent or conceive of certain objects barely or directly; rather we conceive of them through properties in terms of which they can be described or conceived. And in the argument I have just given, we can see in Spinoza a rationalist basis for a descriptivist, anti-direct reference position and for Spinoza’s insistence in Ep. 50 that things are counted or numbered because they have a feature or belong to a kind.16
However, Spinoza departs from Frege in at least two respects.
First, Spinoza seems to regard the kind to which a numbered thing or numbered things belong as a kind which does, or at least can, include a multiplicity of members. Thus Spinoza says when we count a thing we must conceive “another thing” which “agrees with it.” For Spinoza, to see a thing as one—to count it as one—we must in effect, see it as one of many. But why should this be the case? Can’t there be kinds or concepts, in terms of which we count, which are such that only one thing could conceivably fall under them? Isn’t that what we do when we form, for example, the concept of “the integer immediately succeeding 3” and we reckon that there is only one thing that can conceivably fall under this concept—viz. 4? Why then does Spinoza require that to regard a thing as one is to regard it as one of many?
I don’t think that Spinoza ever takes up this question in this form. But I think we can see our way to an answer that Spinoza could give. Notice that when we invoke a concept—such as “the integer immediately succeeding 3”—the concept invoked is complex, containing concepts of a variety of concepts each of which applies to the object—viz. 4—that satisfies the complex concept in question. These constituent concepts—such as “integer” and “successor of 3”—are ones that can apply to more than one thing. In counting our object—viz. 4—as the one object that is the integer immediately succeeding 3, we are thus also in a position to regard that object as falling under a kind or kinds—such as, again, “integer” and “successor of 3”—that apply to more than one thing. So even if there are concepts used in counting—such as “the integer immediately succeeding 3”—that could not conceivably apply to more than one object, such a concept involves attributing to the object other properties that are such that more than one object could have those other properties. Thus, in the end, when we count an object—even in terms of a necessarily unique property—we are also committed to counting the object in terms of a property or properties that can apply to more than one thing.
Spinoza does not argue in this way in order to justify this first departure from Frege, but this justification is open to him. His point then, put more precisely, would be that to count a thing, one must invoke a property that other things can share with that thing or a property that is composed of at least some properties of the thing that it shares or can share with other things.
The second departure from Frege in Spinoza’s conception of what it is to assign a number to a thing concerns the essence or nature of the thing. For Spinoza, not only must we see the numbered items as sharing a certain property or as belonging to a certain class, it must also be the case that that property is the essence or nature of those things. In other words, for Spinoza, to assign a number to a thing is to see it as belonging to a class of things whose members share the same essence. This is clear in both of the central texts in which Spinoza says that God is not properly called “one.” Thus in Ep. 50 Spinoza says:
A thing can be called one or single only in respect of its existence, not of its essence. For we do not conceive things under the category of numbers unless they are included in a common class. [Ep. 50/C II 406/G IV 239]
Spinoza goes on to say that since nothing else can share God’s essence or nature, God cannot be numbered. The implication is that a thing that can be numbered shares its essence with other things. Here Spinoza seems to indicate that to number a thing is to put it in a class of things with the same essence or nature.
Spinoza makes a similar point in CM I, ch. vi. There he points out that God is called one but only improperly so because “there cannot be more than one of the same nature.”17 Again, for a thing to be assigned a number, it must be seen as sharing its nature with other things.18
I am claiming that, for Spinoza, when one numbers a thing, the class (or a class) to which one sees the thing as belonging is a class of things that share the same nature as the thing. And when he says that a numbered thing must “agree” with other things, he means that it must agree in nature with other things. If the class in terms of which things are numbered could be a class of things that do not share the same nature, then it is no longer clear why God could not be numbered—after all, God can be seen as falling into the same class as some other things. For example, God and my body have the property of being extended. This property is not the nature of either me or God. My body’s nature is to have a certain proportion of motion and rest [E2le4–E2le5]. God’s nature is to consist “of an infinity of attributes, of which each one expresses an eternal and infinite essence” [E1d6]. If the classes that interest Spinoza in Ep. 50 are not classes of things of the same nature, then it is no longer clear why God cannot be numbered. Thus, for Spinoza, the common class under which a numbered thing falls must be a class of things of the same nature.19
Why, however, would Spinoza place such a strong requirement on what it is to consider a thing numerically? I think that Spinoza’s view that to think of a thing in terms of number requires conceiving of it as sharing an essence follows from the fact that, for Spinoza, to conceive of a thing one must conceive of it in terms of its essence. This is what I have elsewhere called Spinoza’s essence requirement on representation.
Before seeing the strong reasons Spinoza has for espousing the essence requirement (and thus for espousing the additional, strong requirement that numbered things must share the same essence), let’s examine the textual reasons for attributing this view to Spinoza.
The central piece of textual evidence for attributing the essence requirement to Spinoza is E2d2—Spinoza’s definition of that which pertains to the essence of a thing. Spinoza says:
I say that to the essence of any thing belongs that which, being given, the thing is necessarily posited and which, being taken away, the thing is necessarily taken away; or that without which the thing can neither be nor be conceived, and which can neither be nor be conceived without the thing. [E2d2]
Spinoza claims here (in part) that a thing cannot be conceived without its essence or, equivalently—given the way Spinoza understands the notion of “conceived without” in terms of conceptual involvement20—Spinoza is saying in E2d2 that the concept of a thing involves the concept of its essence.
A similar linkage between the representation or conception of a thing and the representation or conception of its essence is evident from Spinoza’s equation of the idea of a thing and its objective essence in TIE §36 and TIE §41 and KV-A2, §7.
Further, Spinoza’s identification of the idea of a thing and its definition in Ep. 60 (“idea, sive definitio”) also suggests that representation proceeds via a grasp of essence. Spinoza accepts the traditional view that the definition of a thing states its essence.21 Thus in identifying idea and definition in Ep. 60, Spinoza indicates that the representation of a thing is a representation of its essence.22
Why does Spinoza accept the essence requirement on representation? After all, it is a rather implausible requirement, so it would seem that a very good reason would be needed to accept it. As I have argued elsewhere, this very good reason—in Spinoza’s eyes—for the essence requirement consists of two claims to which he is deeply committed: the Principle of Sufficient Reason and the explanatory or conceptual separation between the attributes. The latter is the claim that each of the attributes is conceived through itself [E1p10s]. I want to call attention here to an important implication of Spinoza’s conceptual barrier between the attributes: Spinoza infers from this separation that nothing mental can be explained by anything extended and vice versa [E2p6 and E3p2].
With this point in mind, consider what would be the case if I represented or conceived of an extended thing, x, not in terms of its essence (or of a feature that follows simply from the essence of x), but instead conceived of it in terms of a feature, F, that is not due to the essence of x alone, but is instead in part due to some other thing, y.
To see what would, for Spinoza, be wrong with a scenario, ask the following question: Given that the idea is about the thing that has F, why is that idea about x in particular? Spinoza’s Principle of Sufficient Reason dictates that there must be an answer to this question. The answer, it seems, is that this is because x is the thing with F. Fine, but this fact—that x is the thing with F—depends, as we stipulated, on some object other than x, namely, y. Because x is extended and because—given the explanatory barrier between the attributes—extended things interact only with other extended things, y too must be extended. In light of the fact that the idea of the thing with F is about x because x is the thing with F, and in light of the fact that x is the thing with F because of some other object, y, it follows that the idea is of x because of some other object, y. And now we reach something that would trouble Spinoza: a certain mental fact—that an idea represents a certain object—is explained by a certain fact concerning not thought, but extension, namely, the fact that y exists. But this explanation of something mental in terms of something extended would violate the explanatory barrier. A similar problem would arise, I believe, for each purported case of representation of a thing in terms of its non-essential features.
By contrast, the same problem does not arise for representation of a thing in terms of its essence. The parallel question here would be: Given that the idea is of the thing with essence E, why is it of x? Answer: because x is the thing with E. And here we reach a natural stopping point to our questioning, for the next question would be: Why does x have essence E? (In the same way, we asked in the previous case: Why is x the thing with F?) In contrast to the previous case, this question answers itself: x has essence E simply because that is what it is to be x. So, for Spinoza, given that the idea is of the thing with E, the reason that the idea represents x in particular does not invoke any dependence on an extended object and thus does not violate the explanatory barrier between thought and extension. For Spinoza, in the case of representation of a thing in terms of its essence, which object is represented is determined simply by the nature of the thought itself and by the features grasped in the thought. No help from any extended object, such as y, is required, and so the explanatory barrier is preserved.
Evidence that Spinoza holds the general view that the explanatory barrier precludes factors other than thought from determining the object of representation can be found in E2p5 and E2p5d:
Ideas, both of God’s attributes and of singular things, admit not the objects themselves, or the things perceived, as their efficient cause, but God himself insofar as he is a thinking thing. [E2p5]
This is evident from E2p3. For there we inferred that God can form the idea of his essence, and of all the things that follow necessarily from it, solely from the fact that God is a thinking thing, and not from the fact that he is the object of his own ideas. [E2p5d]
Spinoza here seems to say that the fact that there is an idea of a particular object is to be explained completely in mental terms and not in terms of any other attribute. This consideration would rule out representation of things that does not proceed via a grasp of their essence.23
The essence requirement on representation helps us to understand why Spinoza holds that to regard a thing numerically is to regard it as a member of a class all of whose members share the same essence. Since to represent a thing in terms of number is to see it as belonging to a certain class whose members share a certain property, and since to represent a thing is to represent it as having a certain essence, to represent a thing in terms of number is to represent it as belonging to a certain class all of whose members share that essence. If the class in terms of which we enumerate a thing were a class of things that did not share the essence of the thing in question then we would, in enumerating the thing, be seeing it in terms of a feature other than its essence. And thus we would be violating Spinoza’s essence requirement on representation.
One might think that perhaps we can first secure reference to a thing by thinking of it in terms of its essence—just as the essence requirement specifies—and then go on to enumerate that thing by focusing on some further property that does not constitute its essence but that it shares with other things. In this way the shared property need not be the essence of the thing that is enumerated.24 This two-step strategy would not, however, avoid the problem at hand, for to the extent that one is focusing on the non-essential property then—given the essence requirement—one is no longer genuinely representing the object. In moving to a focus on the shared property, one loses one’s focus on the essence of the object, and one’s thought that is employed in the attempted enumeration is thus no longer really a thought of the object in question. Again, the essence requirement is violated.
In this light, we can see how Spinoza’s theory of number, according to which to regard some thing numerically is to regard the thing as one of many of the same nature, is grounded in Spinoza’s views on what is required to represent a thing, which, in turn, are grounded in his fundamental commitment to the Principle of Sufficient Reason and the explanatory separation of the attributes.
III. Number and Substance
Exactly how we are to understand this separation between the attributes is a matter that will be illuminated once we apply our understanding of Spinoza’s views on counting to his views on substance and attribute. To see God numerically—to see God as one of many—is, given Spinoza’s account of number, to see God as one of many that share the same nature. But, for Spinoza, nothing but God can have the nature that God has. God’s nature, as we have seen, is to be a substance consisting of an infinity of attributes. No other thing can have that nature, of course. Thus, God cannot be seen in terms of number. God cannot be one, for God cannot be one of many of the same nature.
How, then, are we to make sense of Spinoza’s claim that God is one and that there is only one substance, namely, God? It may help here to distinguish between a strict or proper sense of “one” and a loose or improper sense of “one.” That Spinoza would recognize some such distinction is apparent from his speaking of “improperly” calling God “one” which suggests that a proper/improper distinction is available in this context.
To say that a thing is one presupposes that it exists.25 Further, the reason that God is not properly called one is that, despite the fact that God exists, there are not many of the same nature as God. This suggests that:
[one-p] x is one in the proper sense (or one-p) just in case x exists and there are others of the same nature as x.
This characterization of “one” and the similar characterizations to follow are not definitions. Defining “one” in terms of there being or not being others of a certain nature is problematic because, it could be argued, the notion of an other presupposes the notion of one. So the above claim would be illegitimately circular if it were intended as a definition. But as a mere characterization of a kind of oneness it can, perhaps, be illuminating, even if ultimately circular.
In light of this characterization, we can say that, for Spinoza, God is not one-p.26 However, in the lead-up to Spinoza’s claim in E1p14c1 that God is one, Spinoza establishes that there are no other substances—or other things—of the same nature as God.27 This foundation for his claim of one-ness in E1p14c1—a claim that he elsewhere labels “improper”—indicates that the improper sense of “one” can be characterized this way:
[one-i] x is one in the improper sense (or one-i) just in case x exists and it is not the case that there are other things of the same nature as x.28
Notice that the proper and improper senses of “one” are differentiated by the fact that the final conjunct in one characterization is the negation of the final conjunct in the other characterization. That is, the characterizations differ in that the conjunct in one characterization concerning whether or not things are of the same nature is negated in the other characterization. This kind of difference between proper and improper senses will be repeated in other contexts, as we will soon see.
Before we turn to other similar notions with proper and improper senses in Spinoza, I want to point out that, just as God is one-i and not one-p, so too the extended substance is one-i and not one-p. The extended substance is not one-p because, although the extended substance exists, there are no others of the same nature as the extended substance. The nature of the extended substance is simply the attribute of extension. E1p5—the no-shared attribute thesis—implies that there is no other substance whose nature is extension. Thus the extended substance is not one-p. But the extended substance is one-i for it exists and, as we have just seen, there are no others of the same nature. Similarly, the thinking substance is one-i, but not one-p.
If the essence or nature of the extended substance is extension and if the essence of God is—as we saw—to consist of an infinity of attributes, how then are God and the extended substance related: Are they the same or not? And how are their essences related: are they the same or not? It is to this kind of question that I now turn.
Spinoza often speaks of things as being “one and the same” [una eademque].29 Thus, for example, Spinoza says in E2p7s that the thinking substance and the extended substance are one and the same, and that a mode of extension and the idea of that mode are one and the same. Given the presence of the term “one” and given the proper/improper distinction that we have just outlined with regard to “one,” we’d expect a similar ambiguity in the case of “one and the same,” i.e., we’d expect that there would be in Spinoza a commitment to proper and improper senses of “one and the same.” Similarly, given the ambiguity of “one and the same” and given that “many” can be seen as the opposite of “one and the same”—as Spinoza says in CM I, ch. vi: “unity and multiplicity are opposites”—we’d expect there to be proper and improper senses of “many” as well as of “one and the same.” Further, given their opposition, we would expect “one and the same” and “many” to be characterizable in terms of each other.
In this light, how are we to characterize the claim that x and y are one and the same? Let’s focus first on the proper sense of this term. In order for x and y to be one-and-the-same-p, i.e., one and the same in the proper sense, x and y must both exist. (In the same way, the first conjunct of the claim that x is one is, as we saw, the claim that x exists.) So, “x and y exist” should be the first conjunct in the characterization of “one-and-the-same-p.”
Second, since, as I noted, “one and the same” is the opposite of “many,” we can say that if x and y are one and the same in the proper sense, then they are not many in the proper sense. Exactly what it is for things to be many in the proper sense we will turn to in a moment.
To complete the characterization of “one and the same” in the proper sense, note that “one and the same” can be seen as a numerical notion and that, as we saw, to see things in terms of number is, for Spinoza, to see them as sharing a nature with other things. One way to see x and y in the numerical terms indicated by “one and the same” is thus to see x and y as of the same nature.30
In this light, here is a characterization of being one and the same in the proper sense:
[one and the same-p] x and y are one-and-the-same-p just in case x and y exist, x and y are not many-p, and x and y are of the same nature.
In the same vein, we can characterize what it is to be many in the proper sense. Recall that “one and the same” and “many” are opposites, and so it is natural for them to be characterized in terms of each other. With these features in mind, we can say the following:
[many-p] x and y are many-p just in case x and y exist, x and y are not one-and-the-same-p, and x and y are of the same nature.
To arrive at the improper senses of “one and the same” and of “many,” recall that the improper sense of “one” differed from the proper sense of “one” only insofar as the conjunct concerning whether there are things of the same nature is affirmed in the characterization of one sense and denied in the other. In this light, the characterizations of the improper senses of “one and the same” and of “many” would be the following:
[one-and-the-same-i] x and y are one-and-the-same-i just in case x and y exist, x and y are not many-p, and it is not the case that x and y are of the same nature.
[many-i] x and y are many-i just in case x and y exist, x and y are not one-and-the-same-p, and it is not the case that x and y are of the same nature.
With these distinctions between proper and improper senses of “one and the same” and of “many” in hand, let’s consider the relation between the thinking substance, the extended substance, and God. Consider the thinking substance and the extended substance first. They are not one-and-the-same-p because the thinking substance and the extended substance differ in nature. The nature of the thinking substance is thought and the nature of the extended substance is extension, and no substances share attributes. Notice also that the thinking substance and the extended substance are not many-p. This is for the same reason that they are not one-and-the-same-p, namely, they are not of the same nature. But in light of the fact that the thinking substance and the extended substance are neither one-and-the-same-p nor many-p, we can reach the conclusion that the thinking substance and the extended substance are one-and-the-same-i. Notice that all the relevant conjuncts are satisfied in this case: the thinking substance and the extended substance exist, they are not many in the proper sense, and it is not the case that they are of the same nature. Thus when Spinoza says in E2p7s that “the thinking substance and the extended substance are one and the same substance,” what he says can be seen as true if “one and the same” is understood in the improper sense.
But notice that while the thinking substance and the extended substance are one-and-the-same-i, they are also many-i, for consider: the thinking substance and the extended substance exist, they are not one-and-the same-p, and it is not the case that they are of the same nature.
In this light, we can see that God and the thinking substance are one-and-the same-i (but not one-and-the same-p) and that they are many-i (but not many-p). Similarly for the relation between God and the extended substance.
Thus Spinoza’s strictures concerning “one” and number, and his distinction between proper and improper senses of “one” put his substance monism in an entirely new light. Just as God may be called “one” only improperly, so too the thinking substance and the extended substance may be called “one and the same” only improperly. And while the thinking substance and the extended substance are properly speaking not many, they may be called many-i, just as they may be called one-and-the-same-i.
IV. Number and Attributes
How much of this apparatus and how much of this ambiguity in Spinoza concerning “one and the same” applies to Spinoza’s notion of attribute? It might seem that whatever nuances and complications that we get into when considering whether substance is one, it is nonetheless obvious that the attributes are many, that they are distinct, and that they are in no sense one and the same. After all, isn’t it clear that God has an infinity of attributes [E1d6] which are, as Spinoza is at pains to state [E1p10s, etc.], independent of one another? Thus attributes, Spinoza says, may be conceived to be really distinct [E1p10s]. And since, as Spinoza makes clear in E2p7s, the intellect that is so conceiving them is the infinite intellect, and since all ideas insofar as they are in the infinite intellect are true [E2p32], it is hard to avoid the conclusion that the attributes are really distinct and are many and are not one and the same.
It is for such reasons such that many commentators have over the years seen fit to reject Wolfson’s interpretation according to which:
The two attributes appear to the mind as being distinct from each other. In reality, however, they are one […]. The two attributes must […] be one and identical with substance.31
For Wolfson, any distinction among attributes is an illusion of the finite intellect: “attributes are only in intellectu” and “to be perceived by the mind means to be invented by the mind.”32 Since the distinction between attributes is illusory, for Wolfson, and thus mind-dependent, his reading falls within an idealist tradition.
In the same vein, Hegel says:
Spinoza does not demonstrate how these two [attributes] are evolved from the one substance […]. Neither are extension and thought anything to him in themselves, or in truth, but only externally; for their difference is a mere matter of the understanding, which is ranked by Spinoza only among affections.33
But although there may seem to be strong textual reasons against the view that there is no multiplicity of attributes for Spinoza, matters begin to look much different when we see the issue of the multiplicity—the many-ness—of attributes in light of Spinoza’s general views about one-ness and many-ness. Indeed, given that Spinoza explicitly indicates that one-ness (and thus many-ness) are to be understood in different senses, we have no choice but to rethink Spinoza’s apparent views on the many-ness of attributes in light of these different senses.
Before we apply my Spinozistic characterizations of “one” and “many” to the attributes, note that, for Spinoza, the nature of an attribute is just that attribute itself. The nature of extension is just extension, and the nature of thought is just thought. That attributes have natures is explicit in E1p21 where Spinoza speaks of the “absolute nature” of an attribute, and it is apparent from the discussion of thought in E1p21d that thought’s nature is just thought. That any attribute’s nature is just that attribute itself makes sense if we consider that, for Spinoza, attributes are self-conceived [E1p10] and in themselves [E1p29s].
So let’s turn to the question of one-ness—“Is extension one?”—keeping in mind our characterizations of the proper and improper senses of “one” which I provide again here for convenience:
[one-p] x is one-p just in case x exists and there are others of the same nature as x.
[one-i] x is one-i just in case x exists and it is not the case that there are other things of the same nature as x.
It is clear that extension is not one-p because there are no other things of the same nature. Nothing else but extension has the nature extension. If another attribute also has the nature extension, then that “other” attribute would simply be extension.
But just as the fact that there are no others of the same nature as extension shows that it is not one-p, the same fact shows that extension is one-i. Similarly, thought is one-i, but not one-p, just as, as we saw, God is one-i, but not one-p.
Let’s ask the crucial question: Are thought and extension one and the same or are they many? Again, we must approach this question in light of the distinction between proper and improper senses of these terms. Here again are the relevant characterizations:
[one-and-the-same-p] x and y are one-and-the-same-p just in case x and y exist, x and y are not many-p, and x and y are of the same nature.
[one-and-the-same-i] x and y are one-and-the-same-i just in case x and y exist, x and y are not many-p, and it is not the case that x and y are of the same nature.
[many-p] x and y are many-p just in case x and y exist, x and y are not one-and-the-same-p, and x and y are of the same nature.
[many-i] x and y are many-i just in case x and y exist, x and y are not one-and-the-same-p, and it is not the case that x and y are of the same nature.
It is clear that thought and extension are neither one-and-the-same-p nor many-p (just as neither is one-p). And this is because thought and extension do not share natures (just as substances do not share attributes). The fact that the attributes are neither one-and-the-same-p nor many-p demonstrates that, fundamentally, numerical concepts do not apply to attributes any more than they do to substances.
However, precisely because thought and extension are not of the same nature (and because they are not many-p), thought and extension are one-and-the-same-i. For similar reasons, as we saw, the thinking substance and the extended substance are one-and-the-same-i.
And precisely because thought and extension are not of the same nature (and because they are not one-and-the-same-p), thought and extension are many-i.
Similarly, we can see that God and thought, say, are not one-and-the-same-p or many-p (for they are of different natures). But God and thought are one-and-the-same-i and many-i. Similar points apply to the “pair” of God and extension. In general, in Spinoza’s view, for the same reason that God is not properly called “one,” the attributes are not properly called “many.” Just as Spinoza is speaking improperly—as he acknowledges—when he says in E1p14c1 that God is the only substance, so too he is speaking improperly when he says that there are different attributes. In general, number-presupposing notions such as many-ness, distinction, and being one and the same do not apply to attributes any more than these notions apply to substance.
V. The Partial Rehabilitation of Wolfson
In this light, let’s return to the interpretations of Wolfson and of some idealist readers of Spinoza. Such interpreters have come under fire for saying that the attributes are the same, but we can now see that such attacks are importantly unfair, for in a certain respect Wolfson is right.34 Thought and extension are the one and the same at least in the improper sense of that term. Further, properly speaking there is no multiplicity as far as attributes are concerned, just as Wolfson says. Wolfson was also attacked for saying that the attributes are the same as God or substance. But here too he was right: extension and God are one and the same—i.e., in the improper sense.
What Wolfson should have added is that the attributes, in addition to being one-and-the-same-i, are also many-i and are also not one-and-the-same-p and not many-p. Still, Wolfson is right in an important respect because the attributes are indeed one and the same, i.e., they are one-and-the-same-i.
However, there is an even deeper respect in which—despite the partial vindication I have offered—his conclusions are wrong. Wolfson says that the distinction of the attributes is “invented by the mind”35 and thus illusory. This is one of the main reasons for saying that such an interpretation is idealist: distinction among attributes is somehow dependent on mind or thought.
But, by means of the framework I have offered, we can see that in saying that attributes are distinct, we need not be guilty of any confused or inadequate thought. Yes, to say that thought and extension are many-p would be to think inadequately simply because it is not true that thought and extension are many-p. Notice, however, that thought and extension are not many-p simply because thought and extension are not of the same nature. So, there is no reason to regard the thought that thought and extension are not many-p as inadequate. Equally, there is no reason to regard the thought that thought and extension are many-i as inadequate. After all, to have this thought is just to think that thought and extension exist and are not one-and-the-same-p, and that it is not the case that thought and extension are of the same nature. Each of these conjuncts is true, as we have just seen.
The thought that thought and extension are many-p would be inadequate, but one who affirms that thought and extension are many or different need not be asserting the (false) claim that thought and extension are many-p. Rather, such a proponent of the many-ness of attributes may have in mind simply the correct thought that they are many-i, i.e., that thought and extension exist, they are not one-and-the-same-p, and it is not the case that they are of the same nature. There is nothing that need be inadequate in this thought that the attributes are many-i.
Thus the attributes are the same (in the improper sense) and to this extent Wolfson is right. Nonetheless, he fails to acknowledge that it is equally true that the attributes are many in a sense, i.e., improperly speaking. And, perhaps even more significantly, he fails to see that in saying that the attributes are many in this sense, we are not taking part in any illusions. To the extent that the idealist reading, as far as the attributes are concerned, is based on the supposition that claiming that the attributes are many must be an illusion, such a reading is not well-grounded.
Of course, it may still be the case that for other, more general reasons apart from an alleged illusion, any distinction between the attributes may be seen as dependent on thought and thus as fitting into an overall idealist system. As I have argued elsewhere and as I mentioned at the beginning of this chapter, the Principle of Sufficient Reason itself provides such a general reason for seeing idealism at work in Spinoza’s philosophy when it comes to the issue of the many-ness of the attributes.36 My point here, though, is that the idealism with regard to the many-ness of the attributes is not, contrary to what Wolfson and others claim, a function of any illusions.
VI. Number and Modes
Things get even more complicated, however, when we turn from attributes to modes and investigate whether and in what sense Spinoza may be an idealist when it comes to modes. It may be that seeing modes as many is dependent on illusion or inadequate thinking in a way that seeing attributes as many is not.
To see how this is so, we need to crank up our machinery of the one and the many once again and apply it to modes. And in order to do this, it is necessary to make a controversial—but, as I will argue, textually well-grounded—observation about Spinoza’s notion of essence. The observation is that not only is the essence of God unique, as well as the essence of the thinking substance and the essence of the extended substance, and similarly for the attributes of extension and of thought, but it is also the case that the essence of each thing—including modes—is unique to that thing.
To see that such a notion of essence is at work in Spinoza, return to his definition of that which pertains to the essence of a thing:
I say that to the essence of any thing belongs that which, being given, the thing is necessarily posited and which, being taken away, the thing is necessarily taken away; or that without which the thing can neither be nor be conceived, and which can neither be nor be conceived without the thing. [E2d2]
I want to focus on that part of this definition where Spinoza claims that if the essence (or that which pertains to the essence) of a thing, x, is given, then x is also given. If a thing other than x were to have the essence as well, then it would seem that this essence could be posited without x being posited—for, as long as y which is distinct from x is present, the essence in question could, it seems, be posited without x being posited. But since Spinoza is saying in this definition that the essence cannot be posited without the thing being posited, it must be the case that no thing distinct from x also has this essence. The point here is general, and so we reach the conclusion that, for Spinoza, essences are unique: each thing has a unique essence.37
This reading of E2d2 is confirmed by the way Spinoza invokes E2d2 in E2p37, which states:
What is common to all things […] and is equally in the part and in the whole does not constitute the essence of any singular thing. [E2p37]
The proof runs as follows:
If you deny this, conceive (if possible) that it does constitute the essence of some singular thing, say the essence of B. Then (by E2d2) it can neither be nor be conceived without B. But this is contrary to the hypothesis. Therefore, it does not pertain to the essence of B, nor does it constitute the essence of any other singular thing. [E2p37d]
Spinoza’s point here is that if a feature is common to each thing, then it cannot constitute the essence of any particular thing, say B. This is because if this feature is common to all things—to B and other things—then this feature can be (and can be conceived) without B in particular. But this conclusion—Spinoza indicates here—would go against E2d2’s claim that that which pertains to the essence of thing can neither be nor be conceived without the thing. Thus no common property can constitute the essence of any particular thing.
The reasoning Spinoza employs here would also establish the stronger conclusion that no feature common not to all things but to more than one thing can constitute the essence of any given thing. Let’s say that there is a feature common to x, y, and z. This feature cannot constitute the essence of x because, given that this feature is common to more than one thing, the feature can be and can be conceived without x in particular. And, again, this result would be incompatible with the claim that this feature constitutes the essence of x. The conclusion is, again, general, and we reach the broad claim that no feature that is shared by more than one thing can constitute the essence of any particular thing. Thus—just as we concluded from E2d2 itself—essences must be unique.38
Spinoza sometimes says that individual things—such as men—share the same nature. For example, in E1p17s, Spinoza says, that men “can agree entirely according to their essence” [G II 63]. I think that this shared nature is not the individual nature of any particular thing or man, but is, rather, a feature shared by some, but not all, things. The definition of “man” Spinoza speaks of in E1p17s and E1p8s2 and elsewhere does not, I think, capture the essence of an individual man, but instead, perhaps, captures what it is to be a certain kind of thing and not the essence of any particular thing.39
What, then, is the essence of particular modes? As I mentioned, Spinoza tells us in the case of any composite finite mode of extension that its essence is to have a certain proportion of motion and rest [E2le4–5]. More generally, the essence of a complex mode whether extended or not is to have a tendency to preserve a certain relation among the individuals that make up the complex mode [E3p7].40
The fact that no two modes share the same essence has surprising consequences for the number and individuation of modes.
First, consider a mode of thought—mt1—and a mode of extension—meA—that is parallel to that mode of thought. That is, consider the mode of extension that plays the same causal role in the series of modes of extension that the mode of thought plays in the realm of thought. Spinoza says explicitly that these modes are one and the same. In light of our Spinozistic machinery of one and many, we can see that they are one and the same only in the improper sense and not in the proper sense. This is because, given that mt1 and meA are not of the same nature, they are neither many-p nor one-and-the-same-p. And in light of the fact that they are neither many-p nor one-and-the-same-p, it follows that meA and mt1 are many-i and, as I’ve said, one-and-the-same-i. Thus, we can see that when Spinoza says that mt1 and meA are one and the same, what he says can be seen as true if “one and the same” is understood in the improper sense.
Next consider two modes of extension: meA and meB. These modes occupy different locations in the series of modes of extension, and they play different causal roles within extension. Spinoza thus regards these modes as different or as many and not one and the same. This claim is correct but it must be placed in the context provided by our machinery concerning one and many. Thus we can see that since meA and meB (despite both being extended) are of different natures, they are neither one and the same nor many in the proper sense. However, given that they are neither one and the same nor many in the proper sense, they are both one and the same in the improper sense and many in the improper sense. Thus when Spinoza indicates that modes of extension are different or many, what he says can be seen as true if “many” is understood in the improper sense. Similar conclusions apply to any “two” modes of thought or any “pair” of a mode of thought and a mode of extension.
It might seem to be an unfortunate implication of this reading that in the sense in which my mind and my body are one and the same (viz., in the improper sense I have isolated), my mind and your body are also one and the same. After all, my mind and your body do not share the same nature, and that is enough to show that they are one-and-the-same-i. But don’t we want my mind and my body to be one and the same for Spinoza in a sense in which my mind and your body are not? Yes, perhaps we do, and perhaps an additional sense of “one and the same” different from those I have focused on in this chapter can also be seen as at work in Spinoza. To articulate such an additional sense, I would turn first to the notion of sharing attribute-neutral features, features that do not presuppose one attribute or the other. Arguably—and, indeed, I have made precisely this argument in my work on mind-body identity in Spinoza41—my mind and my body share all attribute-neutral features, while my mind and your body do not. Such a sense of “one and the same” focused on shared attribute-neutral features is well worth developing, but it is important to note two points. First, this sense would still not be a proper sense of “one and the same” because it trades on an improper notion of number. Second, this sense can co-exist peacefully with the improper sense of “one and the same”—i.e., “one-and-the-same-i”—that I have identified as at work in Spinoza.
In general, number-presupposing notions such as many-ness, distinction, and being one and the same do not apply to modes any more than these notions apply to substances or to attributes. If we say that modes are distinct or many, we are speaking improperly, for Spinoza, in precisely the same way that for him when we speak of God as one we are speaking improperly. Further, as I have contended, when we speak of attributes as many, we are speaking improperly. Strictly, there is, for Spinoza, on my reading, no differentiation or many-ness in the world. I would only add that strictly there is no one-ness in the world either. Strictly, number-presupposing notions do not apply to reality.42
We can see, however, that in one important respect—relevant to the question of idealism—the case of modes differs from the case of substance and attributes. We saw earlier that in saying that the thinking substance and the extended substance are one and the same in the improper sense or that the attributes are many in the improper sense, we are not under any illusion. To take the case of attributes in particular, recall that to say that the attributes are many-i is to say that they exist, they are not one-p, and they are not of the same nature. Each of these conjuncts is straightforwardly true, for Spinoza, because the number-presupposing commitments have been eliminated. So in saying that the attributes are many-i, we are not under any misapprehension or illusion.43 And, thus, as I said, there is no basis for seeing Spinoza as an idealist with respect to the distinction among the attributes, at least not for the reason that such a distinction would be illusory or a mere product of the mind.
By contrast, there is a reason to see Spinoza as regarding the many-ness of the modes—i.e., their many-ness in the improper sense—as involving some kind of illusion or at least incoherence. This incoherence gives rise to a kind of idealism with regard to modes that is not present with regard to substance or attributes.
To say that modes A and B are many in the improper sense is to say that they exist, they are not one-and-the-same-p, and that it is not the case that they are of the same nature. As in the case of attributes, each of these claims regarding modes may seem to be straightforwardly true. If this is the case, then Spinoza would not be an idealist with regard to modes on the ground that the perception of them as distinct involves some kind of illusion.
However, if we look more closely, we can see an incoherence in the claim of the many-ness of modes. This incoherence stems from an application of Spinoza’s notion of essence and his notion of number, the two notions that drive the claim of many-ness here. Thus, consider more carefully the first conjunct in the characterization of the claim that the modes are many-i: modes A and B exist. What exactly is it for a mode to exist? E1d5 tells us: “By mode I understand the affections of substance, or that which is in another through which it is also conceived.”44 This definition of “mode” indicates that each mode is such that, by its very nature, it depends on—it is in and conceived through—an other. This other is ultimately the substance of which the mode is a mode, and, as Spinoza makes clear in the second half of Ethics Part 1, modes may also depend by their nature on other modes.
I want to focus on this word “other” [alio], for it does, after all, presuppose the notion of number. If a mode—mode A—is, by its nature, other than some thing (call this other “God”), then mode A and God are more than one, they are at least two, they are many. But now let’s crank up the machinery of number yet again. In order for mode A and God to be seen in this numerical light dictated by the very notion of what it is to be a mode, we must see mode A and God as belonging to a class of things all of which share the same nature. But, as I’ve stressed, for Spinoza no two things share the same nature. So the worry is that, although the very notion of mode involves the notion of other-ness and thus involves both the notion of number and the claim that there are things that share the same nature, no two things can share the same nature for Spinoza. Thus the very notion of mode presupposes something that is inconceivable by Spinoza’s lights—viz., the sharing of essences and the applicability of number. And so, any notion of distinction among modes is likewise incoherent. Thus the first conjunct in the characterization of mode A and mode B are many—a claim that presupposes that modes exist—is not coherent.
Of course, while it may be true that nothing can be a mode and that there can be no distinction among modes, perhaps—in keeping with Spinoza’s own distinction between proper and improper ways of speaking—it may nonetheless be the case that speaking improperly we can say that there are modes and there are distinctions among modes. Perhaps, we can say that, although properly speaking, for a mode to exist is for certain things to share an essence—something that cannot be the case—nonetheless, speaking improperly, we can say that mode A exists.
What would this improper way of speaking be? We can say that mode A exists in the improper sense just in case:
mode A exists,
God exists,
mode A depends on God, and
mode A and God are not one-and-the-same-p.
This last conjunct is meant to capture the content that is improperly expressed by saying that the mode is other than the substance.
However, this improper expression of “mode A exists” still relies on the claim that mode A exists. And so we ask: Is the conjunct “mode A exists” to be understood in the proper or improper sense? As we have seen, the strict sense of “mode A exists” is incoherent. So the first conjunct of the expression of “mode A exists” in the improper sense must be “mode A exists in the improper sense.” We thus have not succeeded in giving a characterization of “mode A exists in the improper sense” other than by saying that mode A exists in the improper sense.
There seems to be no way to state the existence of a mode that does not rely on an improper use of terms. The numerical notions cannot be eliminated or replaced by non-numerical notions. Likewise, “modes A and B are many” can be expressed only improperly for the expression of “modes A and B are many in the improper sense” relies upon the claim that mode A exists which can only improperly be expressed.
Does the notion that, for example, the thinking substance exists or the notion that the attributes exist lead to similar difficulties? As far as I can see, it does not. “Mode A exists” is problematic because this claim turns on the notion of other-ness. But the notions of God or thinking substance or extended substance or thought or extension do not turn on the notion of an other. Substance is, after all, conceived through itself. It is not conceived through another. Similarly, attributes are self-conceived. So, unlike the notion of modes, the notions of substance and of attributes are free from the taint of other-ness, difference, and number that renders the notion of modes incoherent or only improperly expressible.
This interpretation of the content of the claim that mode A exists—viz., “mode A exists, God exists, mode A depends on God, and mode A and God are not one-and-the-same-p”—may shed light on Spinoza’s third kind of knowledge. It turns out that the only positive aspect of the content of the idea that mode A exists—an aspect that is not hidden behind a negation or that is not an aspect that involves improper expressions—is that expressed by “God exists.” To the extent that a conception of a mode has genuine, positive content, it is just the idea that God exists. This suggests that the adequate idea of a mode is really just an adequate idea of God and that adequate ideas of different modes are really just the idea of God and not different ideas after all. The development of this account of the third kind of knowledge in Spinoza is a topic I leave for another occasion.45
Because any thought of a distinction among modes is likewise only improperly expressible, well might Hegel and his allies think that the notion of Spinozistic modes and of their distinction involves some kind of illusion. And well might Spinoza be seen as committed to acosmism, just as Hegel charged.46 In this light, any distinction among modes is not a feature of reality, but is somehow mind-dependent or an illusion. This would be a kind of idealism when it comes to modes. And, as I noted, this kind of idealism in Spinoza would be additional to the general kind of idealism that stems from the mind-dependence of all things that is embedded in the Principle of Sufficient Reason.
I am aware, of course, that this interpretation, one broadly sympathetic to a Hegelian idealist interpretation and one broadly in keeping with an Eleatic reading of Spinoza, may seem to be in tension with a number of texts in which Spinoza seems committed to a multiplicity of attributes or modes, for example, Spinoza’s apparent commitment to multiplicity in his talk of the order and connection of things—a notion that is central to his so-called parallelism [E2p7]. In this connection, we must also point out that Spinoza’s talk of intuitive knowledge of finite things [e.g., in E5p22 and E5p31] straightforwardly seems to commit him to genuine multiplicity.47
I do not have the space here to address the relevant passages, so I will limit myself to two general comments. First, in this chapter I have tried to isolate an aspect of Spinoza’s thinking about one, many, and differentiation. This may or may not be an aspect that he always has uppermost in his mind, but it is a line of thought that does real work in Spinoza’s system and is expressive of a genuine metaphysical commitment of his. If we downplay or dismiss this way of thinking about number in Spinoza, then we are failing to appreciate something real in Spinoza’s thought.
Second, I think that many or, perhaps, even all of the passages that may seem to conflict with my reading can be handled by invoking some variation of the proper/improper distinction that Spinoza invokes and that I have relied on throughout this chapter. Thus the differentiation presupposed by order and connection and by the apparently distinct instances of the third kind of knowledge may turn on the notion of many-i, i.e., on many-ness spoken of improperly.
So, for Spinoza, not only is it the case that whatever is is dependent on thought, but it is also the case that substance and attributes are coherently thinkable in a way that modes—with all their other-ness—are not. And this differential status of modes, on the one hand, and substance and attributes, on the other, is due to the difference whereby the notions of substance and of attribute, unlike that of modes, are free of the problematic notion of something different, of an other. It is this difference with regard to difference and other-ness that makes all the difference in the world. And, as we can now see, all the difference in the world is really no difference at all.
Notes
1 Many of the ideas in this chapter were forged in the most congenial crucible of my seminar on Spinoza at Yale in the spring semester of 2016. I am grateful to all the members of the seminar for their challenges and engagement. I am also grateful to the lively participants at the 2016 Leibniz-Spinoza workshop at Michigan State University, at a colloquium at the New School in December 2016, at a Jacob Perlow lecture at Skidmore College in March 2017, at an early modern philosophy workshop in Tel Aviv in April 2017, at the Collegium Spinozanum in Groningen in July 2017, at a Yale faculty lunch in December 2017, and of course at the conference in Paris that generated this volume. Thanks also are due to many others including especially Jack Stetter, Charles Ramond, Pierre-François Moreau, Chantal Jaquet, Martin Lin, Yitzhak Melamed, John Grey, Noa Naaman-Zauderer, Alison Peterman, Mogens Lærke, Alex Silverman, Stefanos Regkas, Ohad Nachtomy, and of course Pascal Sévérac whose generous comments at the Colloque International Spinoza France États-Unis were insightful and most welcoming. Alex Silverman’s penetrating response to and criticism of this chapter (in his “Monism and Number: A Case Study in the Development of Spinoza’s Philosophy,” History of Philosophy Quarterly 34 (2017): 213–230) has already appeared in print: thus my chapter should definitely not be considered the last word.
2 On this kind of idealism in Spinoza stemming from the Principle of Sufficient Reason, see Michael Della Rocca, “Rationalism, Idealism, Monism, and Beyond,” in Spinoza and German Idealism, ed. Eckhart Förster and Yitzhak Melamed (Cambridge: Cambridge University Press, 2012). For the Principle of Sufficient Reason-oriented reading of Spinoza, see my Spinoza (New York: Routledge, 2008) and “Interpreting Spinoza: The Real Is the Rational,” Journal of the History of Philosophy 53, no. 3 (2015): 523–536.
3 G. W. F. Hegel, Lectures on the History Philosophy, trans. E. S. Haldane and Frances H. Simson, 3 vols (Lincoln, NE: University of Nebraska Press, 1995); Harold H. Joachim, A Study of the Ethics of Spinoza (Oxford: Clarendon Press, 1901).
4 Harry Austryn Wolfson, The Philosophy of Spinoza: Unfolding the Latent Processes of His Reasoning, 2 vols (Cambridge, MA: Harvard University Press, 1934).
5 For a classic and powerful rebuttal of Wolfson’s interpretation, see Martial Gueroult, Spinoza 1: Dieu (Paris: Aubier-Montaigne, 1968), appendix 3.
6 See Michael Della Rocca, Representation and the Mind-Body Problem in Spinoza (New York: Oxford University Press, 1996), ch. 9.
7 See, for example, Della Rocca, “Rationalism, Idealism, Monism, and Beyond” and Michael Della Rocca, “Rationalism run amok: Representation and the reality of emotions in Spinoza,” in Interpreting Spinoza, ed. Charlie Huenemann (Cambridge: Cambridge University Press, 2008). For an acute discussion of—though not an endorsement of—the acosmist reading, see Yitzhak Y. Melamed, “Acosmism or Weak Individuals? Hegel, Spinoza, and the Reality of the Finite,” Journal of the History of Philosophy 48, no. 1 (2010): 77–92.
8 “Hinc clarissime sequitur Deum esse unicum hoc est (per definitionem 6) in rerum natura non nisi unam substantiam dari” [E1p14c1/G II 56].
9 For these and similar passages, see Mogens Lærke, “Spinoza’s Monism? What Monism?” in Spinoza on Monism, ed. Philip Goff (Basingstoke: Palgrave Macmillan, 2010), 244 and 259n3.
10 Ibid.
11 “Si rem accuratius examinere vellemus, possemus forte ostendere Deum non nisi improprie unum, et unicum vocari” [CM I, ch. iv/G I 246].
12 “Certum est, eum, qui Deum unum, vel unicum nuncupat, nullam de Deo veram habere ideam, vel improprie de eo loqui” [Ep. 50/G IV 240].
13 See also: Pierre Macherey, “Spinoza est-il moniste?” in Spinoza: Puissance et ontologie, ed. Myriam Revault d’Allonnes and Hadi Rizk (Paris: Éditions Kimé, 1987); Gilles Deleuze, Spinoza: Practical Philosophy, trans. Robert Hurley (San Francisco, CA: City Lights Books, 1988); and Gueroult, Spinoza 1, appendix 17.
14 Frege quotes part of this passage in Foundations of Arithemetic, §49 (see The Frege Reader, ed. Michael Beaney (Oxford: Blackwell, 1997), 101). For a discussion of Frege’s engagement with Spinoza on this point, see Gueroult, Spinoza 1, appendix 17.
15 For Spinoza’s rejection of brute facts, see, for example, E1p11d2: “For each thing there must be assigned a cause, or reason, both for its existence and for its nonexistence.” Elsewhere, I’ve argued that for Spinoza the rejection of brute things is equally, in the context of Spinoza’s system, a rejection of brute facts. See Della Rocca, “Interpreting Spinoza,” 525–526.
16 It would be interesting to explore whether there is a similarly rationalist basis both for Frege’s descriptivism and for his Spinozistic view on counting as made possible by a grasp of a concept under which counted items fall.
17 “Ejusdem naturae plures esse non posse” [CM I, ch. vi/G I 246].
18 See also E1p8s2 [G II 51] and Ep. 34 [G IV 179–180]. In both of these texts, the numbered things are said to share the same nature.
19 Lærke sees Spinoza in this light as well: “Being one is inconceivable without the conception of several of the same nature and, a fortiori, inconceivable without the conceivability of several of the same nature” (Lærke, “Spinoza’s Monism?,” 255).
20 See E2p49d: “To say that A must involve the concept of B is the same as to say that A cannot be conceived without B.”
21 See E3p4d, TIE §95, and Della Rocca, Representation, 88.
22 See Della Rocca, Representation, 86.
23 This paragraph and the previous two paragraphs are adapted from Della Rocca, Spinoza, 96–98. A different way of employing the Principle of Sufficient Reason and the explanatory barrier between the attributes in order to reach the conclusion that representation of a thing proceeds via representation of its essence can be constructed if we appeal to the equivalence of existence and intelligibility in Spinoza. See Della Rocca, Spinoza, 264–265 and Michael Della Rocca, “Spinoza and the Metaphysics of Scepticism,” Mind 116, no. 464 (2007): 851–874.
24 For this objection, I am indebted to John Grey.
25 Cf. Spinoza’s claim in CM I, ch. vi that “unity is not in any way distinct from the thing itself.”
26 See also Ohad Nachtomy, “A Tale of Two Thinkers, One Meeting, and Three Degrees of Infinity: Leibniz and Spinoza (1675–8),” British Journal for the History of Philosophy 19 (2011): 935–961, esp. 947: “The infinity of the divine substance cannot be quantified or measured but rather belongs to a different category all together.”
27 See, in particular, E1p5.
28 Lærke offers a similar characterization of the sense of “one ” in E1p14c1 as “not several, i.e. [.… ] there is not another one” (“Spinoza’s Monism,” 257). Cf. Macherey: “Dieu [.… ] est unique, en ce sens qu’il n’est pas plusieurs” (“Spinoza est-il Moniste ?”). My characterization differs from these in emphasizing, as Lærke himself does elsewhere (as I noted above), that there is not another one of the same nature.
29 My understanding of this phrase has been challenged and deepened by Alex Silverman’s important work. See Alex Silverman, The Union of Thought and Being in Spinoza. PhD dissertation. Yale University, 2014.
30 We might also want to specify that there are other things, besides x and y, of the same nature, but I will drop this further claim since it will not have any impact on the differentiation of proper and improper senses of the terms in question.
31 Wolfson, The Philosophy of Spinoza, 156.
32 Ibid., 146.
33 Hegel, Lectures on the History of Philosophy, vol. 3, 268–269. For a discussion of this aspect of Hegel’s interpretation, see Gueroult, Spinoza 1, 464.
34 For a different critique of objectivist, non-Wolfsonian readings of attributes in Spinoza, see Noa Shein, “The false dichotomy between objective and subjective interpretations of Spinoza’s theory of attributes,” British Journal for the History of Philosophy 17, no. 3 (2009): 505–532.
35 Wolfson, The Philosophy of Spinoza, 146.
36 See Della Rocca, “Rationalism, Idealism, Monism, and Beyond,” 22–26.
37 For similar readings of E2d2, see Yirmiyahu Yovel, Spinoza and Other Heretics, 2 vols (Princeton, NJ: Princeton University Press, 1989), vol. 1, 163 and Olli Koistinen, On the Metaphysics of Spinoza’s Ethics. Reports from the Department of Theoretical Philosophy. University of Turku, 1991, 13–14. Cf. Pascal Sévérac, Spinoza (Paris: Vrin, 2011), 58: “Ce par quoi se définit l’essence d’une chose ne peut être commun à plusieurs choses.”
38 Other passages that suggest that essences are unique for Spinoza: “If God had created all men like Adam was before the fall, then he would have created only Adam, and not Peter or Paul. But God’s true perfection is that he gives all things their essence, from the least to the greatest” [KV, I, ch. vi/G I 43]; “Things must agree with their particular Ideas, whose being must be a perfect essence, and not with universal ones” [KV, I, ch. x/G I 49]. See also KV, II, pref., §5 which contains an early version of E2d2.
39 On this kind of point, see Karolina Hübner, “Spinoza on Essences, Universals, and Beings of Reason,” Pacific Philosophical Quarterly 97, no. 2 (2015): 58–88.
40 See Della Rocca, Representation, ch. 2.
41 Ibid., ch. 7.
42 Cf. Gueroult, Spinoza 1, 582: “il [l’entendement] n’a pas en lui la notion du nombre, puisque le nombre se fonde sur le discret.” Alison Peterman and Eric Schliesser reach similar conclusions in their important papers which deal with number and measure in Spinoza, though their arguments do not proceed via the considerations I have raised here concerning the proper and improper senses of “one,” etc. See Alison Peterman, “Spinoza on Extension,” Philosophers’ Imprint 15, no. 14 (2015): 1–23, and Eric Schliesser, “Spinoza and Science: Mathematics, Motion, and Being,” in The Oxford Handbook of Spinoza, ed. Michael Della Rocca (New York: Oxford University Press, 2017).
43 Similarly, as I claimed, in saying that the thinking substance and the extended substance are one and the same, we are not under any misapprehension or illusion.
44 “Per modum intelligo substantiae affectiones sive id quod in alio est, per quod etiam concipitur” [E1d5/G II 45].
45 For an excellent treatment of the third kind of knowledge which has helped me in the formulation of this notion that I offer here, see Kristin Primus, “Scientia Intuitiva in the Ethics,” in Spinoza’s Ethics: A Critical Guide, ed. Yitzhak Y. Melamed (Cambridge: Cambridge University Press, 2017).
46 In a series of papers and in my book Spinoza, I have reached similar conclusions about the non-reality of modes by means of a very different, but equally rationalist, argument centered not, as the current argument is, on number and essence, but on the tight connections between Spinoza’s notion of in-ness (or inherence), conception, and causation. See, for example, Della Rocca, “Rationalism run amok.”
47 For these criticisms, see Yitzhak Y. Melamed, “Why Spinoza Is not an Eleatic Monist (Or Why Diversity Exists),” in Spinoza on Monism, ed. Philip Goff (Basingstoke: Palgrave Macmillan, 2010), 206–222. Gueroult (in Spinoza 1, appendix 3) also challenges Eleatic readings of Spinoza.