Nor is this all. After sharply distinguishing what is from what is not, and refusing to admit any intermediary between them, Aristotle proceeds to discover such an intermediary in the shape of what he calls Accidental Predication.[236] An accident is an attribute not necessarily or usually inhering in its subject—in other words, a co-existence not dependent on causation. Aristotle could never distinguish between the two notions of cause and kind, nor yet between interferences with the action of some particular cause and exceptions to the law of causation in general; and so he could not frame an intelligible theory of chance. Some propositions, he tells us, are necessarily true, others are only generally true; and it is the exceptions to the latter which constitute accident; as, for instance, when a cold day happens to come in the middle of summer. So also a man is necessarily an animal, but only exceptionally white. Such distinctions are not uninteresting, for they prove with what difficulties the idea of invariable sequence had to contend before even the highest intellects could grasp it. There was a constant liability to confound the order of succession with the order of co-existence, the order of our sensations with the order of objective existence, and the subjection of human actions to any fixed order, with the impossibility of deliberation and choice. The earlier Greek thinkers had proclaimed that all things existed by necessity; but with their purely geometrical or historical point of view, they entirely ignored the more complex questions raised by theories about classification, logical attribution, and moral responsibility. And the modifications introduced by Epicurus, into the old physics, show us how unanswerable Aristotle’s reasonings seemed to some of his ablest successors. Absolute being is next distinguished from truth, which, we are told, has no objective existence[237]—a remarkable declaration, which throws much light on other parts of the Aristotelian system, and to which we shall subsequently return.[238]