Fichte wrote in "The Science of Knowledge" "An in itself returning activity (Egohood, subjectivity) is character of the rational being. The positing of itself (reflecting about itself) is an act of this activity. Let this reflection be called A. The rational being posits itself through the act of such an activity. All reflection reflects something as its object; let this object be called B. Now, what sort of a something must this object be as object of the reflection A. In A the rational being is to posit itself, is to be its own object; but its character is in itself returning activity. The last highest object (B) of its reflection must therefore also be in itself returning, or itself determining activity, since otherwise it would not posit itself as a rational being, and hence would not posit itself at all." ... "The question has been asked, What "was" I before I became self-conscious? The answer is, I was not at all, for I was not I. The Ego is only in so far as it is conscious of itself. …. The proposition not A is not A will doubtless be recognized by every one as certain, and it is scarcely to be expected that any one will ask for its proof. If, however, such a proof were possible, it must in our system be deduced from the proposition A=A. But such a proof is impossible."