Kant's evolution, which makes dogmatism to result from scepticism, was an entirely moral evolution, substituting for speculative the authority of practical reason. The evolution we have now to deal with is of a quite different character; it consists in passing from objective to subjective knowledge, from the object to the subject. Even if all that has been just said on the side of criticism were true, there is at least invariably one existence that remains untouched by it: this existence is that of the thinking subject, and this existence is incontestable. What appears to us as a circle to the circumference are objects, in the centre is the subject. We do not confound ourselves with our sensations, we distinguish between them and ourselves. Can, then, this consciousness of the thinking subject be no more than the transformation of external events? No; for all exterior events reduce themselves to one--_i.e._, motion; and all interior events to one--_i.e._, thought. There is no transition or transformation possible between one of these phenomena and the other. "We acknowledge," says a distinguished savant, Professor Tyndall, "that a definite thought and a molecular action of the brain occur simultaneously, but we do not possess the essential organ, nor even a rudiment of the organ we should require in order to pass by reasoning from the one to the other." Thus, then, the subject exists and is not reducible to the object. Shall we say that this subject is nothing more than a sum of phenomena? But what adds up these phenomena? A common bond is needed. Have we any consciousness of such a bond? "Yes," replies our author, "we call internal states of consciousness, past, present, or possible; we attribute them to ourselves, we say that they take place within us. What does this mean if the _ego_ to which we refer them is only their succession? How comprehend the continuity of consciousness?" In a word, our author admits absolutely that the _ego_ has a consciousness of its own being, as distinct from its sensations and from external objects. "It is," he says, "an activity constantly modified, but yet always one, which dominating its states refers them to the unity of one same consciousness."