Arcesilaus further gives effect to the distinctions which are more particularly brought up in modern times, and relied upon. “If comprehension is the assent given to a conception of thought, it does not exist. For, in the first place, the assent is not on account of a conception, but of a reason; that is to say, it is only as regards axioms that this assent holds good.”[171] That is good; more fully the purport would be something like this: Thought, as subjective, is made to assent to an existence which is a determinate content of the conception. A sensuous image such as this, however, is foreign to thought, and with it thought cannot accord, because it is something different from it, something from which thought, on the contrary, holds itself aloof. It is, in general, only to a thought that thought finds itself conformable, and only in a thought that it finds itself; thus only a universal axiom is capable of such accord, for only such abstract principles are immediately pure thoughts. Arcesilaus thus holds it up against the Stoics that their principle contains a contradiction within itself, because the conception of thought is made to be the thought of another, but thought can only think itself. This is a thought which concerns the inmost essence of the thing. Arcesilaus thus here makes the same celebrated distinction as in recent times has again been brought forward with so much force as the opposition between thought and Being, ideality and reality, subjective and objective. Things are something different from me. How can I attain to things? Thought is the independent determination of a content as universal; but a given content is individual and hence we cannot assent to such. The one is here, the other there; subjective and objective cannot pass to one another—this is a form of thought upon which for long the whole culture of modern philosophy has turned, and which we still find to-day. It is important to have a consciousness of this difference, and to assert this consciousness against the principle of the Stoics. It was of this unity of thought and reality that the Stoics ought to have given an account; and this they did not do, and indeed it was never done in ancient times. For the ancients did not prove that the subjective element of thought and this objective content are really in their diversity the passing into one another, and that this identity is their truth; this was only found in Plato in an abstract form and as a first commencement. The unity of thought and conception is the difficult matter; thus if thought, as such, is the principle, it is abstract. The logic of the Stoics hence remained formal merely, and the attainment of a content could not be demonstrated. Thought and Being are themselves such abstractions, and we may move to and fro between them for long without arriving at any determination. Thus this unity of universal and particular cannot be the criterion. With the Stoics the conception as comprehended appears to be immediately asserted; it is a concrete, but it is not shown that this is the truth of these distinct elements. Against this immediately accepted concrete, the assertion of the difference of the two is thus quite consistent.