So in Propositions 4 to 6, Spinoza has constructed the idea of purposive individuals as collections of interacting relationships, each of which tends to preserve the structure of the whole collection. In Propositions 7 and 8 he clarifies this idea, before beginning to apply it to humans in Proposition 9.
1) Proposition 7
The ‘striving’ that all things have, “is nothing else but the actual essence of the thing in question.”
The proof of this is somewhat obscure, although there’s mention of determinism (“things [have no] power except what necessarily follows from their nature as determined”). There’s one obvious respect in which a thing’s striving ‘is’ its essence, namely that its causal power comes from the causal processes that define it – essence is defined causally. But there’s another sense, which will emerge in discussing P8.
2) Proposition 8
This ‘striving’ “involves no finite time, but an indefinite time.”
The proof this time is fairly clear in structure: “If it involved a limited time…it would then follow solely [from the thing’s essence] that the thing could not exist beyond the limits of that time, but that it must be destroyed”, and this is held to violate P4, that things can’t destroy themselves because they can’t have contradictory essences.
Of course, this follows only we interpret P4 very strictly – something might have a long-term instability that makes it incapable of existing for more than a year, but nevertheless be sufficiently stable that for most purposes it’s useful to treat it as a stable individual, analyse its essence, etc. So P8 might seem fairly inconsequential, just a statement of what applies ‘in the strictest sense’.
But P8 is actually very significant, when we compare it with normal ideas of ‘striving’, of aiming at goals. Normally we suppose that such goals necessarily deal with a finite time, because they aim to fulfil some goal in the future, and if this succeeds, the striving ceases. After all, the point of goals is normally to be something different from how things presently are.
So it’s a big deal that Spinoza denies this – it also fits closely with his idea that goals are ultimately a matter of ‘self-preservation’. Both claims present the same problem: if what you’re striving for is not a future state but merely your own existence, how can it be anything other than the present state (in which, after all, you clearly exist)? And if it’s just the present state, you’re not really ‘striving for a goal’, are you? That would seem to make Spinoza a complete ‘mechanist’, with no place at all for teleology.
But I think there’s a way out of this. Consider someone given the following logic-sentences: P→Q, R↔Q, R→¬P, Q. At first, she just has them ‘side-by-side’ in her head, with various possible ideas of whether P is true etc., some of which contradict some of the sentences, others others. Then she tries to hold them all ‘together’, which means working out what allocation of truth-values to the sentences P, Q, and R is compatible with all the above sentences being true.
This goal is clearly something different from just having the sentences jumbled together there in her mind. But it’s also, in a sense, nothing ‘beyond’ those sentences. No new idea is added to them – rather, they are fitted together in the only consistent way they can be. But this ‘fitting-together’ is immanent in the sentences themselves.
I think Spinozistic teleology is something like this. A thing which is subject to stresses, pressures, tensions, instabilities, is one in which its own component relations are in conflict, disrupting each other. It ‘aims at’ the state where those same relations interact, but harmoniously, stably.
For instance, when I squeeze something, the parts get closer together and repel each other, a response which tends towards a situation where those parts are further apart again and no longer repel each other (or at least do so less).
The ‘goal’ of teleological action is the entity’s own structure, but as a harmony instead of a cacophony. In this sense the goal is ‘immanent in’ its actual state, but also differs from it. And this completely ‘contradiction free’ version of an entity’s internal relations is, as we have seen, what Spinoza means by a thing’s ‘essence’.
This brings us back to P7: a thing’s striving is not only ‘powered by’ the relations that compose its essence, but it aims at the consistent and complete instantiation of that essence.