Chapter II. Of The Mind; The Ethics
D2: I say that to the essence of any thing belonds that which, being given, the thing is [also] necessarily posited and which, being taken away, the thing is necessarily [also] 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. [my emphasis]
D3: By idea I understand a concept of the mind which the mind forms because it is a thinking thing.
Exp.: I say concept rather than perception, because the word perception seems to indicate that the mind is acted on by the object. But concept seems to express an action of the mind.
D7: By singular things I understand things that are finite and have a determinate existence. And if a number of individuals so concur in one action that together they are all the cause of one effect, I consider them all, to that extent, as one singular thing.
Spinoza’s epistemology is eerie, naturalistic, and strictly logical. However, this axiom is difficult to digest without qualms.
A5: We neither feel nor perceive any singular things, except bodies and modes of thinking.
Now, “feeling” and “bodies” are quite easily to conceptually grasp. We experience sensations and the corresponding bodies which exist are necessarily posited given that we do in fact sense something, namely the bodies given. “Perceiving” cannot be said to be only a form of “feeling”, as if just a synonym. Necessarily, for Spinoza, all our perceptions are of substance and its modes, but, under a more Spinozistic definition, what we “perceive” are the “modes of thought.” Therefore, our perceptions are constituted with what we perceive of the modes of thinking.
In Spinoza’s Metaphysical Thoughts, appended to his exposition of Cartesian philosophy, he distinguishes between “modes of reason (or thought)”, “chimaeras”, and “ficticious beings.” The first, modes of thought, are concepts such as love, sorrow, doubt, and so on; chimaeras would be contradictions, such as the proposition “She loves me, and she does not love me” (not that she hates me, because “hate” is but a contrary to “love”—Spinoza admits we can have contraries existing in our minds with the same object as a target of these affects, hate and love); and ficticious beings, or fictions, are propositions we take to believe because those propositions appeal to our finite intellects which constantly battle with our passions.
Yet, given this axiom, by Spinoza’s understanding, fictions and contradictions are never actually and truly perceived or felt. Perhaps, neither of these entities truly exist in Nature. Could we say, at least initially, that we posit the “contradiction”—or the law of noncontradiction—as a cognitive instrument or, even worse, a tendency of our minds? But what of the “fiction”? Can we deny that our states of belief contain meaning? I’m sure we could doubt the claim that belief-states do. Of course, this is all hinged on the assumption that Spinoza maintained his views consistently since the publication of his Metaphysical Thoughts up to the publication of his Ethics. We have no reason to believe he did not, and we should try our best to understand seemingly inconsistent notions from the text for our lack of understand may simply be an attempt of our mind to simply reject the consequences which perturb us. Namely, an argument may be raised which proposes “yes, of course we experience or perceive real, or classical, contradictions” or “people latch onto, after perceiving, fictions all the time!”
Indeed, it is difficult to take Spinoza at face value for a postulate he takes to be an axiom. It is strange that he would consider it as such without any hesitation (by “hesitation”, I refer to something like his disclaimer at P8 of Chapter 1 regarding P7), but, of course, he labored rigorously over the Ethics. So, he must have had good reason to grace the chapter with such an axiom, rather than attempting to demonstrate it as a proposition. That said, I will adhere to the Principle of Sufficient Reason so that I may determine the true nature of this seemingly strangely axiom; it may be a trivial answer or a mere lapse in my recollection of Spinoza’s text, but nevertheless, an answer shall be obtained!