Indeed, in the first case, if the natural sciences be of a philosophic nature and represent a first approximation to philosophy, they must disappear when philosophy is evolved, as the provisional disappears before the definite, as the proof before the printed book. This would mean that natural sciences as such do not exist and that what really exists is philosophy. In the second case, if philosophy have the same nature as the natural sciences, the further development of the first sketch will always be the work of the naturalistic method, however refined and however increased in power we may please to imagine it. Thus, what would really exist would never be philosophy, but always the natural sciences. This erroneous conception therefore reduces itself to a denial, either of the natural sciences or of philosophy; either of the pseudoconcepts or of the pure concepts; a negation that need not be confuted, because the whole of our exposition of Logic is its explicit confutation. [Sidenote: _Motive of these errors: naturalistic philosophy._] The genesis of such a psychological illusion resides in the fact that the natural sciences seem to be tormented with the thirst for full and real truth, and philosophy, on the other hand, to be intent solely upon correcting the perversions and inexactitudes of the empirical and natural sciences. But it is a question of likeness or appearance only, because the thirst for truth belongs not to the natural sciences, but to philosophy, which lives in all men, and also in the naturalist. And the philosophic perversions and inexactitudes which have to be corrected do not form part of the natural sciences (which as such affirm neither the true nor the false), but to that philosophy which the naturalist forms and into which he introduces the prejudices derived from his special business. [Sidenote: _Philosophy as destroyer of naturalistic philosophy, but not of the natural sciences. Autonomy of these._]