These two extremely fruitful thoughts of Oken, on account of the absurd form in which he expressed them, were at first little heeded, or entirely misunderstood, and it was reserved for a much later era to establish them by actual observation. The supposition that the individual species of plants and animals originated from common prototypes by a slow and gradual development of the higher organisms out of lower ones, was of course most closely connected with these ideas. Man’s descent from lower organisms was likewise asserted by Oken—“Man has been developed, not created.” Although many arbitrary perversities and extravagant fancies may be found in Oken’s philosophy of nature, they must not prevent us paying our just admiration to these grand ideas, which were so far in advance of their age. This much is clearly evident from the statements of Goethe and Oken which we have quoted, and from the views of Lamarck and Geoffroy which have to be discussed next, that during the first decade of our century no doctrine approached so nearly to the natural Theory of Descent, newly established by Darwin, as the much decried “Natur-philosophie.” CHAPTER V. THEORY OF DEVELOPMENT ACCORDING TO KANT AND LAMARCK. Kant’s Dualistic Biology.—His Conception of the Origin of Inorganic Nature by Mechanical Causes, of Organic Nature by Causes acting for a Definite Purpose.—Contradiction of this Conception with his leaning towards the Theory of Descent.—Kant’s Genealogical Theory of Development.—Its Limitation by his Teleology.—Comparison of Genealogical Biology with Comparative Philology.—Views in favour of the Theory of Descent entertained by Leopold Buch, Bär, Schleiden, Unger, Schaafhausen, Victor Carus, Büchner.—French Nature-philosophy.—Lamarck’s Philosophie Zoologique.—Lamarck’s Monistic (mechanical) System of Nature.—His Views of the Interaction of the Two Organic Formative Tendencies of Inheritance and Adaptation.—Lamarck’s Conception of Man’s Development from Ape-like Mammals.—Geoffroy St. Hilaire’s, Naudin’s, and Lecoq’s Defence of the Theory of Descent.—English Nature-philosophy.—Views in favour of the Theory of Descent, entertained by Erasmus Darwin, W. Herbert, Grant, Freke, Herbert Spencer, Hooker, Huxley.—The Double Merit of Charles Darwin.