MODERN BIOLOGY 47:^ 



to Stand. This is characteristic of him; the more a theory takes it upon itself 

 to explain, the more convincing does he consider it to be.^ But exact and 

 critical research has not dealt thus with the theories; it has set up theories 

 according as special research has required them, but it has never expanded 

 them beyond the bounds of absolute necessity. Darwin is here, as so often 

 elsewhere, a speculative natural philosopher, not a natural scientist. 



Darwin on the descent of man 

 This speculative characteristic is still more conspicuous in his next work, 

 The Descent of Man, and Selection in Relation to Sex, which was published three 

 years after the former book, but which was likewise written after many 

 years of preparation. In The Origin of Species he had already in passing ex- 

 pressed the opinion that natural selection would without doubt eventually 

 throw light also on the origin of man — an assertion that was enough to 

 excite very great attention. The subject had already been taken up by others: 

 by Huxley and, above all, by Haeckel, and it was thus no longer a matter 

 of real urgency. Darwin's presentation of it, however, possesses an interest of 

 its own. His arguments that man has through natural selection by means of 

 the struggle for existence been evolved from a series of animal forms are, 

 of course, the same as those he had previously developed in regard to the 

 animals; the anatomical and embryological argumentation he was able to 

 borrow from his above-mentioned predecessors. It may be pointed out, 

 however, that he does not insist upon man's relationship with the anthropoid 

 apes, as Haeckel has done; he observes, it is true, physical and psychical 

 agreements, but otherwise maintains for the most part man's character of a 

 mammal. Of greater interest, however, is his derivation of the human 

 psychical qualities; he analyses a number of such qualities of different kinds — 

 curiosity, the tendency to imitate, memory, imagination, reflection — and 

 he finds them existing also in the animals. He even notices an equivalent to 

 religious feelings in the dog's awe of his master. On the whole, he falls into 

 the same error as innumerable animal psychologists since then, of letting 

 qualities that man has through training inculcated into his domestic animals 

 be regarded as spontaneous manifestations of the intellect. As to the existence 

 of moral qualities, he refers to the characteristics of self-sacrifice and social 

 sense to be found in many animal forms — in regard to the ants he holds in 

 this respect the same exaggerated ideas as many of his contemporaries — 



^ As an instance of how boldly Darwin takes up the most difficult problems for discussion, 

 and how casually he afterwards solves them, the following may be cited (Variations, I, p. 8). 

 He maintains that, in spite of natural selection, very simple life-forms have nevertheless been 

 preserved through the ages by adapting themselves to very simple conditions of life: "for what 

 would it profit an Infusorial animalcule for instance or an intestinal worm to become highly 

 organized?" It must be admitted that, if the problem is difficult to solve, the answer certainly 

 makes it none the easier. 



