UC Davis Philosophy 22N

Spinoza Lecture Notes

G. J. Mattey

Revised January 18, 2007

Spinoza's first published work was Principles of the Philosophy of René Descartes. Published in 1663, it was the only work published under Spinoza's own name. This work is thought to be a demonstration of his understanding of Descartes, which would deflect any criticism for misrepresenting Descartes's views when he later developed a philosophical system which repudiated many key Cartesian doctrines. The full metaphysical system for which Spinoza was best known is found in the Ethics, which was published by his friends shortly after his death in 1677.

The organization of the Ethics follows that of textbooks of geometry. In each of its five parts, Spinoza lays down a series of definitions, axioms, and postulates. His goal is to prove metaphysical "propositions," which would be analogous to geometrical theorems. The model for this approach is found in Descartes's replies to the second set of objections to the Meditations, which attempts to prove four key metaphysical propositions.

Monism

Spinoza's philosophical views were quite shocking for his times, so much so that publication of his main work would have placed him in serious danger. After the posthumous appearance of the Ethics, Spinoza was commonly reviled as an atheist, notwithstanding the fact that his metaphysical system is centered around God. The charge of atheism arises from the fact that he identified the entire universe with God, so that God is the only thing that exists. His system was a version of monism, the metaphysical doctrine that only a single thing exists. It could also be called pantheism, which is the doctrine that God is not distinct from the universe as a whole.

Monism immediately runs up against the question of how to account for the apparent plurality of objects in the universe. The first monist in the Western tradition, Parmenides, simply denied that there is more than one thing. Spinoza was not willing to go so far. He thought that he could account for plurality (in fact, infinite plurality) in a monistic universe. He allowed that there are many minds and many bodies, while at the same time denying that there is more than one thing. Ultimately, the solution to this paradox will depend on the possibility of conceiving one thing in two different ways.

Substance, Attribute, and Mode in Descartes

Spinoza's topic in Part I of the Ethics is metaphysical. He aims to establish the existence and nature of God. His primary tools for accomplishing this task are some basic categories for describing what exists. Since his use of these categories resembles in many respects the way Descartes used them, we shall look back to Descartes before moving forward with Spinoza.

In the geometrical presentation of his system, Descartes gives a definition of "substance." We perceive attributes, and we know by the light of nature that attributes must belong to something. Substance is that to which attributes belong. So a perceived shape must belong to a substance whose shape it is. Descartes uses the scholastic word "inhere" to describe the relation between an attribute and its subject, and he also describes a substances as that through which an attribute exists. It is clear from this account of substance that attribues are metaphysically dependent on substances.

In the Principles, Descartes offered quite a different definition. Substance is understood as "a thing which so exists that it needs no other thing in order to exist" (Principles I, 51). This appears to emphasize the other side of the substance/attribute relation. In the earlier definition, a substance is understood as that on which an attribute depends. In the present definition, it seems, a substance is that which does not depend on an attribute.

But this is not what Descartes had in mind. The independence of substance is relative to other "things" and has to do with the very existence of the subject itself. This is an innovation in metaphysics. It has the immediate consequence that only one being satisifies this definition: God. According to Descartes, our idea of God as an absolutely perfect being is that of a being which exists necessarily and does not depend for its existence on any other being. On the other hand, any being that is not infinitely powerful requires another being to bring about and sustain its existence. Since only God is infinitely powerful (a claim that Spinoza tried to prove), there is only one existentially independent being, and hence only one substance in the sense just defined.

Philosophers since Aristotle have held that there are many substances. Catholic theology claimed that human beings are substances created by God, and Descartes that he as a thinking thing is a substance. Since he requires God to initiate and sustain his existence, Descartes is not a substance by his own definition. To overcome this infelicity, Descartes allowed that he and other created things are substances in a relative sense. They depend on nothing other than the concurrence of God to exist. More specifically, Descartes does not depend for his existence on his body.

The treatment of attributes in the Principles is similar to that in the "Replies to the Second Set of Objections." Most generally, what is "possessed by" or "in" substance is called "attribute" (Principles I, 56). Attributes are not substances, but depend entirely on substance. Thought is an attribute of thinking things, and there is no thought without a thinking thing. Extension is an attribute of extended things, and there is no extension without an extended thing.

Attributes are traditionally thought of as ways in which substance exists. For example, my body began as a microscopic speck, then became larger until it reached a certain size. So, if my body is a substance, its size is a modification of it. Descartes used the term "mode" to refer to any attribute that is capable of changing. Modes are "modifications" or "diversifications" of substance. God has only attributes but no modes, because modification is change, and God exists eternally without change (Principles I, 56).

God's attributes are thought, existence, and eternity. A created thinking substance shares with God the attribute of thought and existence, but has the attribute of duration instead of eternity. A created extended substance shares with created thinking substances the attributes of existence and duration but has the attribute of extension rather than thought. Among the attributes, only one is the "principal property of substance which constitutes its nature and essence, and to which all other properties are referred" (Principles I, 53). This attribute is thought in thinking things and extension in extended things. Although Descartes does not make the point explicitly, it is clear that God and created minds share the same principal attribute of thought.

Substance, Attribute, and Mode in Spinoza

We now turn to Part One of the Ethics, "Concerning God." We will begin our treatment by considering some of Spinoza's definitions and then look at a number of important theorems.

Spinoza adopted a definition of substance that is similar to but not the same as that of Descartes. A substance is that which is in itself and is conceived through itself. The idea that substance "is in itself" echoes Descartes's definition of something which needs nothing else to exist. But the additional condition that substance be "conceived through itself" is unique to Spinoza. As will be seen, it plays an important role in Spinoza's demonstrations.

An attribute is what the intellect perceives as being the essence of a substance. Note that this definition makes no mention of the traditionally accepted relation of an attribute to a substance: that it is "in" a substance or "possessed by" a substance. An attribute for Spinoza is like Descartes's "principal attribute," which is the essence of a substance. However, Spinoza does not think that attributes of substance must be unique, or that all other properties of substance must be referred to a single attribute. This is a key difference from Descartes's view and it will prove to be a crucial one.

According to Spinoza, a mode is an "affection" of substance. A mode is in something else and conceived through something else (where the "something else" is substance). It follows immediately from these definitions that modes depend on substance, but substance does not depend on modes (Proposition 1). This definition resembles that of Descartes, in that an "affection" seems to be like a "modification." It makes explicit that the relation of a mode to a substance is that of being "in," and in this way, the definition of "mode" resembles Descartes's definition of "attribute."

The Nature of Substance

With these definitions in hand, Spinoza begins Part I of the Ethics with a series of propositions about what a substance in general must be. He will conclude that whatever is a substance is infinite and that it necessarily exists. Then he will try to show that there can be only one substance, which he identifies with God. In what follows, we will sketch Spinoza's intricate argument to these conclusions.

Spinoza is initially neutral about how many substances there are. His first major conclusion, culminating in Proposition 6, is to show that if there are two substances neither could be produced (i.e., be caused to exist) by the other. A substance B could not brought into existence by a substance A. The argument for this proposition depends on axioms 4 and 5. Axiom 4 states that knowledge of an effect depends on knowledge of the cause, while axiom 5 stipulates that two things can be understood through each other only if they have something in common with each other.

Now suppose that substance A were thought to bring about the existence of substance B. Knowledge of the effect (the new existence of B) requires knowledge of the cause A, by Axiom 4. This dependence of knowledge (B being understood through A) requires, by Axiom 5, that there be something in common between A and B. What is in common between could only be an attribute, since the modes of A and B are specific to them.

To complete the argument, Spinoza must show that no two distinct substances can share attributes in common, which is the claim of Proposition 5. The only way for substances which share attributes to be distinct is that their attributes are modified or affected in different ways. But, Spinoza claims, differences in affections cannot be the basis of the distinctness of two substances.

Yet it seems natural to believe that we can distinguish substances by their modes. You have your thoughts and I have mine, and neither of us has the thoughts of the other. Why does this not imply that we are distinct beings?

At this point, the argument becomes quite subtle. The gist of it is that in order to determine the metaphysical status of a substance (such as that it is the same as or different from another substance), we may only take into account that which is specifically connected to its being a substance. Since substance is prior to its affections (Proposition 1), affections can play no role in determining the identity or difference of one substance or another. The only thing that is so closely tied to the being a substance of a substance is its attributes, which express the essence of the substance.

The conclusion thus far is that the only way substance A can be distinguished from substance B is if they have different attributes. This does not quite get Spinoza the conclusion he wants, however. If substance A and substance B share some, but not all, of their attributes, then they could still be distinct yet share a common attribute necessary for one to cause the other.

This last avenue of escape is blocked by Proposition 2, which states that two substances with different attributes have nothing in common. It seems that Spinoza wants to claim that if there is any difference in attributes between A and B, then A and B have absolutely no attributes in common. The reason for this is supposed to be the definition of substance, according to which a substance is conceived through itself. Now suppose A and B shared an attribute. Then we can conceive A through B and B through A, in which case A and B are not substances.

Let us now summarize this complicated argument. If substance A is to cause substance B to exist, it must do so because A and B share an attribute. If A and B share an attribute, they share all their attributes. If A and B share all their attributes, then they cannot be distinct from each other, since they cannot be distinguished through their modes. Therefore, if A is to cause B to exist, then A must be the same as B. Equivalently, if A and B are distinct, then A cannot be the cause of the existence of B.

If a substance cannot be caused to exist by another substance, its existence can be explained only by self-causation. Spinoza concludes in Proposition 7 that substance in fact is self-caused, and that existence belongs to substance by its very nature. This is a version of the ontological argument for the existence of God, though it is here applied only to "substance" taken generally. It is more bold than Descartes's version, because it relies only on the bare concept of substance, and not on the richer notion of a supremely perfect being.

One must ask at this point, however, why we should think that there must be "substance" whose existence has to be explained. Perhaps no existing thing meets Spinoza's definition, in which case there is no need to appeal to self-causation. The most plausible answer is to be found in Descartes's "Reply to the Second Seto of Objections": we perceive attributes, and no attribute can exist without a substance.

The next move, in Proposition 8, is to claim that substance is infinite. The reason for this is that the attributes of substance can be limited only by other substances with the same attributes. For example, the size of my body is limited by the presence of surrounding bodies. But since substances cannot share any attributes in common, there is no limitation to any attribute of any substance. So, each substance is infinite with respect to each of its attributes.

The definition of "attribute" states that we conceive the essence of substance through its attributes. Descartes had held that each substance has exactly one principal attribute constituting its essence. Spinoza, on the other hand, noted that there is no reason to believe that substance may not have more than one attribute. There can be no conflict among attributes, since each is sufficient by itself to constitute the essence of substance. If it involved a relation to some other attribute (as would be required for a conflict), a given attribute would not be conceived through itself.

God

The more attributes a substance has, the more real it is. We can conceive of a substance which has infinitely many attributes (each of which is itself infinite, as has already been argued). Given that such a substance is possible, and given the fact that any substance necessarily exists, it follows that a most real substance--a substance with infinitely many attributes--exists. This substance is God.

It might be objected that because extension is a possible attribute of substance, it is an attribute of God, and so God can be divided because extended substances are divisible. Spinoza tries to head off this objection in Proposition 12. He argues that it is incompatible with the nature of substance that it be divided. This leaves open the question of how exactly an extended substance can fail to be divisible, but this question will be answered after a further distinction is made below.

Spinoza's God, or substance, is unique. Given that God has all the possible attributes, any other substance would have to share at least one of them. But it has been argued that no two substances can share an attribute. Hence, there is no substance other than God.

The Principle of Plenitude

Because God has infinitely many attributes, each of which is itself infinite, an infinite number of things follow from God's nature in an infinite number of ways. Everything that can be conceived by an infinite intellect (God's intellect) is in fact an effect of God's causality. This is Spinoza's version of what has come to be known as the "principle of plenitude."

The Two Faces of Substance

We can think of God either through the attributes as a substance or through the affections as nature. In one way of thinking, God is an eternal being with infinite attributes. If we think of God in this way, we regard God as "natura naturans." The affections of God belong to God--in the way that my thoughts belong to me. So we can view God from the standpoint of the modes, and when we do we regard God as "natura naturata." This is how we can say that God is infinite in one respect but finite in another respect. It also is a way around Descartes's claim that because there is no variation in God, God has no modes, but only attributes (Principles, Part I, 56). When God is viewed as natura naturans, there indeed can be variation in God.

God's Causality

As discussed above, God needs nothing else in order to exist and therefore is "self-caused." (It must be noted that many philosophers have questioned whether this notion is even coherent, since it seems that a cause must be distinct from its effect. However, Spinoza defines "self caused" as "that whose essence involves existence," and so he is not operating here with the standard notion of causality.) God is also the cause of all the modifications that make up finite things. Spinoza held that God is an "immanent" rather than "transitive" cause. By this he meant that God conceived through the attributes is the source of all affections and hence of the existence of all finite beings. But God is not a member of a causal chain which brings about the existence of any of these beings. All "transitive" causes are themselves affections.

God's causality works in the following way. A new affection at a time is the result of the immediately preceding affections. These affections are the result of affections preceding them, and so on to infinity. (Hence the expression "transitive.") There is no first cause in the chain of changing affections. All causal chains are confined to modes of a single attribute. Thus, the existence of an idea has as its cause only a prior idea, and never a body, which is a mode of the attribute of extension.

Mind and Body

Descartes had a hard time explaining how mind and body could interact. Spinoza seems to have recognized the difficulty in so doing and gave up the project entirely. Instead, he claimed that changes in mind and body occur in a parallel fashion, a doctrine known as "psycho-physical parallelism." The order of change in thought and that in idea correspond perfectly. If I will that my body move, for example, there is a cause of motion in extended things. When light strikes my eyes, there is a prior idea that gives rise to a present idea of a colored shape. (This doctrine is expounded in Part II.)

Freedom, Determinism, and Contingency

God's causality is absolutely free, in the sense that there is nothing outside of God that could be responsible of the changes that occur in God's affections. The source of all of God's acts is to be found within God (in the infinite series of modes, as explained in the penultimate paragraph). But from the standpoint of the modes themselves, there is no trace of freedom. Each mode is completely determined to change as it does by the series of preceding modes (Props. 26-29). From this, Spinoza derives the conclusion that "Nothing in nature is contingent, but all things are from the necessity of the divine nature determined to exist and to act in a definite way" (Prop. 29).

An event is contingent when it depends on some other event in order to occur. It is common in real estate transactions to make a contingency offer. The offer is valid only when some condition (usually the sale of one's present piece of property) has been satisfied. These offers are made because of the uncertainty of whether the condition will be satisfied. A contingent event in the world, in the philosopher's sense, is one that might or might not take place, depending on whether some prior event has taken place or not. For example, whether I move my body is contingent on whether I will to do so or not.

Philosophers like Descartes have held that conditions such as the exercise or non-exercise of the will might or might not be fulfilled. Descartes held, for example, that sometimes the will is indifferent as to how to choose: nothing determines it in one direction or another (Meditation IV. Spinoza rejected this view. When we call a change contingent, according to him, it is not because the change depends on a condition that might or might not occur, but rather because (as in the real-estate example) we do not know whether or not the condition will occur. Presumably, there is a chain of events which will determine whether or not one's present property will be sold. If everyone knew how the chain of events would turn out, there would be no need for contingency offers!

Now one might argue that at Spinoza's strict determinism is incompatible with God's freedom. God has no choice regarding how events will turn out. Spinoza would agree that God has no choice in the direction of the universe. This is because Spinoza's God (unlike Descartes's) does not have an indifferent will. Indeed, Spinoza held that there is no difference between God's intellect, will, and power (Prop. 17). What God recognizes through ideas of things is bound to come to pass through God's very conception of the things. The Cartesian model of God's mind is the human mind, where ideas are proposed by the intellect and actions are carried out by the will. But to Spinoza, the "will" and "intellect" of God are no more like will and intellect of the human "than the celestial constellation of the Dog and the dog that barks" (Prop. 17).

The Human Imagination

The reason people harbor misconceptions about God can be found in the influence of the imagination in our thinking (Appendix). We think of God as having a human-like will because we imagine God to be like a human being. Human will exerts limited power over a tiny part of the universe. We observe events on a vaster scale: earthquakes, floods, volcanic eruptions, etc. We think of them as being governed by a will like ours, because we wish to exert some indirect control over them. We seek to influence, through prayer and sacrifice, the wiill of God of the imagination in ways that will give us aid and comfort. But this is anthropomorphism--the projection of observable human traits onto an otherwise impersonal world.

Anthropomorphism is apparent in human judgments of value. We value the orderly over the disorderly because we find the predictable to be more useful than the unpredictable. So we think of God as having created an orderly world to suit human needs. But Spinoza contended that "disorder" has no less a place in the universe as "order." In fact, the universe is indifferent with respect to "order" and "disorder." We value the "good" over the "bad." But we understand these terms entirely relative to utility for human beings. If we think that everything is designed for the best ends, we once again are guilty of projecting human needs onto a wider world. There are no ends in the world, according to Spinoza, except for the specific ends formed by human beings. In this claim he was resolutely anti-Aristotelian. Indeed, even Descartes had allowed that the world unfolds according to God's ends, ends which will remain unknown to human beings in this life.

Like Descartes, Spinoza sought to prove the primacy of the intellect over the imagination. Descartes had claimed that his discovery of God through rational inquiry was the key to metaphysical knowledge. Spinoza agreed with this claim, but he took it a step further in the last parts of the Ethics. Having argued that traditional religious belief has no grounds, he found that the optimal state of a human being is to contemplate God intellectually. Only in this way can the human being shake its "bondage" to the passions and attain peace of mind.


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