its development, on
instinct, on sexual love, etc., which he very skillfully uses in support of
his metaphysical principle.

%3. From the Revival of the Kantian Philosophy to the Present Time.%

%(a) Neo-Kantianism, Positivism, and Kindred Phenomena.%--The Kantian
philosophy has created two epochs: one at the time of its appearance, and
a second two generations after the death of its author. The new Kantian
movement, which is one of the most prominent characteristics of the
philosophy of the present time, took its beginning a quarter of a century
ago. It is true that even before 1865 individual thinkers like Ernst
Reinhold of Jena (died 1855), the admirer of Fries, J.B. Meyer of Bonn,
K.A. von Reichlin-Meldegg, and others had sought a point of departure for
their views in Kant; that K. Fischer's work on Kant (1860) had given a
lively impulse to the renewed study of the critical philosophy; nay, that
the cry "Back to Kant" had been expressly raised by Fortlage (as early as
1832 in his treatise _The Gaps in the Hegelian System_), and by Zeller
(p. 589). But the movement first became general after F.A. Lange in his
_History of Materialism_ had energetically advocated the Kantian doctrine
according to his special conception of it, after Helmholtz[1] (born 1821)
had called attention to the agreement of the results of physiology with
those of the Critique of Reason, and at the same time Liebmann's youthful
work, _Kant and the Epigones_, in which every chapter ended with the
inexorable refrain, "therefore we must go back to Kant," had given the
strongest expression to the longing of the time.

[Footnote 1: Helmholtz: _On Human Vision_, 1855; _Physiological Optics_,
1867; _Sensations of Tone_, 1863, 4th ed., 1877 [English translation by
Ellis, 2d ed., 1885].]

Otto Liebmann (cf. also the chapter on "The Metamorphoses of the A Priori"
in his _Analysis of Reality_) sees the fundamental truth of criticism in
the irrefutable proof that, space, time, and the categories are functions
of the intellect, and that subject and object are necessary correlates,
inseparable factors of the empirical world, and finds Kant's fundamental
error, which the Epigones have not corrected, but made still worse, in the
non-concept of the thing in itself, which must be expelled from the Kantian
philosophy as a remnant of dogmatism, as a drop of alien blood, and as an
illegitimate invader which has debased it.

According to Friedrich Albert Lange[1]