Spinoza on the Causality of Individuals RICHARD V. MASON PROPOSITION 28 in Part I of Spinoza's Ethics says: "Every individual, or each thing which is finite and has a determined existence, is not able to exist or to be determined to act unless it is determined to exist and act by another cause which is also finite and which has a determined existence: and again, this further cause is not able to exist or to be determined to act unless it is determined to exist and act by another which is again finite and has a determined existence, and so on to infinity.'" In other words: there are endless chains of things or events---or possible one single endless chain-which determine each other's action and existence. Leaving aside any problems about the individuation of events, this seems a fairly commonplace thought. Presumably most of us think that things or events are influenced or affected by each other and that the series of influences extends indefinitely, although we do not imagine that we can see more than a small part of it. Spinoza put this in plain, matter-of-fact terms: "If someone should ask by what cause a finite body is moved, it would be possible to reply that this body is determined to such a motion by another body, and that one again by another and so on, proceeding to infinity.... "' Again, stressing the epistemological point of view, he writes: "... it would be impossible for human weakness to follow up the series of individual mutable things, both because of their multitude beyond all numbering and because of the infinitely diverse circumstances surrounding one and the same thing, any one of which might be the cause why it exists or not. ''s But then how did Spinoza fit his God into this unremarkable picture? God was supposed to be eternal, indivisible and infinite. How could any References are to the standard edition, Spinoza Opera, 4 vols.,edited by C. G. Gebhardt (Heidelberg: Carl Winter, 1925).The translations are my own. Letter 4o, Opera, 4: 198. s Tractatus de Intellec~csEmendatione, Opera, Vol. 2:36. [197] 198 JOURNAL OF THE HISTORY OF PHILOSOPHY being with such properties be related, causally or otherwise, to the existence and action4 of individual things? The difficulty seemed to be an obvious one, to which Spinoza refused to give the most obvious traditional reply: the notion of God as the first cause in all causal series, the ultimate initiator of all causal activity. Leibniz was aware of the apparent difficulty and he brought it out in a particularly clear and pointed way: "[Spinoza] maintains... (Ethics I, 21) that finite and temporal things cannot be produced immediately by an infinite cause, but that (I, u8) they are produced by other causes, individual and finite. But how will they then spring finally from God? For they cannot come from him mediately in this case, since we could never reach in this way things which are not similarly produced by another finite thing. It cannot, therefore, be said that God acts by mediating secondary causes, unless he produces secondary causes.... " He concluded, grinding his own axe: "Therefore it is rather to be said that God produces substances and not their actions, in which he only concurs. ''5 Now if the only problem were to see how Spinoza wanted to bridge the gap between an infinite God and the series of finite events, then the apparatus seemingly proposed for its solution was reasonably obvious, and Leibniz was being less than frank in failing to mention it. The apparatus was outlined in Propositions ~t to ~3 of Ethics Part I. Some of the detail can be filled in from material in Spinoza's letters. Using the terminology of Spinoza throughout, we can say that modes follow from, or are caused by, God. There are infinite modes which necessarily exist and which follow directly from God. These have been called "immediate infinite modes" by commentators . Spinoza gave two examples of them in Letter 64: in the attribute of thought, absolutely infinite understanding, and in the attribute of extension, motion and rest. Other infinite modes--or perhaps there is no...