5Ii THE HISTORY OF BIOLOGY 



true, positively rejected the former's explanation of nature and was but little 

 concerned with its materialistic speculation. But the idea of seeing in Goethe 

 a precursor of a " mechanical science of the organisms ' ' certainly needs some 

 explanation. The great poet was universally looked upon by his age as an 

 idealistic natural philosopher; the biologists who acclaimed him did so under 

 that assumption and he himself had adduced " geistige Krdfte" as a cause of 

 the origin of and modifications in the life-forms, and otherwise also given 

 utterance to markedly spiritualistic views. Whence, then, Haeckel's asser- 

 tion to the contrary? The reason is no doubt to be found partly in Haeckel's 

 own natural-philosophical turn of mind, which could never be induced to 

 take the idea of "mechanism" in existence really seriously, and partly in 

 the position Goethe enjoyed in the cultural life of the period — his influ- 

 ence as a poet and a cultural personality, which was highly admired even 

 in Haeckel's home and circle, and which was opposed by no one beyond 

 the extreme-orthodox ecclesiastical authorities, who found free-thinking and 

 libertinism in his poetry, something which in its turn increased the sym- 

 pathy of the liberals for the really somewhat conservative poet-minister. 

 And the liberal opposition became once and for all one of the leading mo- 

 tives in Haeckel's system of thought. 



The very choice of subject and the consequent title of the work — Gen- 

 eral Morphology — is also obviously borrowed direct from Goethe, who, in 

 fact, invented the word in question and from whom Haeckel also derived 

 the philosophical conception of morphology that he develops in the book. 

 For, strictly speaking, Haeckel was no professional morphologist in the 

 modern sense. He had till then worked almost exclusively on the classifi- 

 cation of single-celled animals; and in the comparative anatomy of the higher 

 animals, especially the Vertebrata, he practically never carried out any spe- 

 cial investigations, at least none of which the results have been published. 

 That he nevertheless based his theoretical speculation not on classification, 

 as Darwin himself did, but on morphology, was no doubt due, as hinted 

 above, to his admiration for Goethe, but also, of course, to the influence 

 exerted on him by his friend Gegenbaur, who was no doubt responsible for 

 the best contributions of facts in the work. But a speculatively inclined 

 student who concerns himself with second-hand knowledge will, of course, 

 easily succumb to the temptation to let his imagination get the better of 

 his critical sense — a fact that finds strong confirmation in Haeckel. 



His ternary division of nature 

 The General Morphology begins with a chapter on the relation between mor- 

 phology and other sciences. First comes an assertion that every natural object 

 possesses three qualities: matter, form, and energy or function. In connexion 

 with this idea natural science is divided into three disciplines: chemistry, 

 or " Stojflehre," morphology, a.nd physics, or '^ Kraftlehre." Then the knowledge 



