Finally, this conception of philosophic history itself declares its untenability, since in its last term it is logically obliged to posit a definitive philosophy (which is that represented by him who constructs such a history of philosophy), whereas there is nothing definitive in reality, which is perpetual development. Those very historians of philosophy themselves, who have desired and in part attempted to give actuality to that conception, have been perplexed at the assumption of so great a responsibility as to proclaim a _definitive philosophy,_ that is to say, to decree the retirement of Thought and so of Reality. [Sidenote: _Philosophism both of this false view and of the formula concerning the identity of philosophy and history of philosophy._] The error which appears in this conception of philosophic history, is the same that we have already studied under the name of philosophism, and which appears here in one of its special applications. The formula of the error is the _identity of Philosophy with the History of philosophy._ The sense in which this is meant is at once shown by the tendency which exists in this identity of the two terms, to be enlarged into a third term, that is to say, into the recognition of the identity of philosophy and of the history of philosophy with the _Philosophy of history._ And this Philosophy of philosophic history, like every philosophy of history, converts representations and empirical concepts into pure concepts assigning to each one the function which properly belongs to the categories, corrupting philosophy and history and becoming shipwrecked in a sort of mythologism and propheticism. [Sidenote: _Distinction between this false idea of a history of philosophy and the books that are so entitled or profess a like programme._]