In his _History of Creation_ (1868) he thus estimates Lamarck's work as a philosopher: "To him will always belong the immortal glory of having for the first time worked out the theory of descent, as an independent scientific theory of the first order, and as the philosophical foundation of the whole science of biology." Referring to the _Philosophie Zoologique_, he says: "This admirable work is the first connected exposition of the theory of descent carried out strictly into all its consequences.

By its purely mechanical method of viewing organic nature, and the strictly philosophical proofs brought forward in it, Lamarck's work is raised far above the prevailing dualistic views of his time; and with the exception of Darwin's work, which appeared just half a century later, we know of none which we could, in this respect, place by the side of the _Philosophie Zoologique_.

How far it was in advance of its time is perhaps best seen from the circumstance that it was not understood by most men, and for fifty years was not spoken of at all.

Cuvier, Lamarck's greatest opponent, in his _Report on the Progress of Natural Science_, in which the most unimportant anatomical investigations are enumerated, does not devote a single word to this work, which forms an epoch in science.

Goethe, also, who took such a lively interest in the French nature-philosophy and in the 'thoughts of kindred minds beyond the Rhine,' nowhere mentions Lamarck, and does not seem to have known the _Philosophie Zoologique_ at all." Again in 1882 Haeckel writes:[55] "We regard it as a truly tragic fact that the _Philosophie Zoologique_ of Lamarck, one of the greatest productions of the great literary period of the beginning of our century, received at first only the slightest notice, and within a few years became wholly forgotten....