52.0 THE HISTORY OF BIOLOGY 



of the molecules, or plastidules, as he calls them, of living matter. Life is 

 due to their atomic structure, and " jedes Atom besitxt eine inhdrente Summe von 

 Kraft und ist in diesem Sinne beseelt." Energy and soul are thus identified anew, 

 and this having been done, all difficulties disappear. Haeckel now explain^ 

 reproduction, as always, with the old definition: growth over and above the 

 individual; heredity is a transmission of the motion of the plastidules, and 

 adaptation a change in this motion. This certainly sounds somewhat me- 

 chanical, but some pages further on we suddenly find a new definition: 

 "Die Erblichkeit ist das Geddchtnis der Plastidule, die Variabilitdt ist die 

 Fassungskraft der Plastidule." And yet still later we are told that "das Ge- 

 ddchtnis"' is a transmitted motion. It would, of course, be superfluous to judge 

 these fancies according to scientific standards ; Haeckel himself admits that 

 he got the idea of "the memory oi" the atoms" from Goethe's famous ro- 

 mance Die Wahlverivandtschaften, and indeed the whole plastidule theory 

 sounds like a romance; in producing it Haeckel had abandoned himself en- 

 tirely to romantic natural philosophy and there he remained for the rest of 

 his life. The phenomenon might seem to have only a psychological interest 

 and might be passed over with a reference to Haeckel's esthetic turn of 

 mind — he was, in fact, something of an artist, a gifted dilettante in water- 

 colour painting and an admirer of beauty both in art and in nature — but 

 it might also be pointed out that a pioneer in science may be considered 

 justified in entertaining some strange thoughts on general problems — this 

 has been acknowledged throughout the ages. Yet this does not explain how 

 it was that this speculative side of Haeckel's activities should have proved 

 capable of creating such an extraordinary sensation among his contempo- 

 raries — that people should have been so loud in their praises and in their 

 abuse. This point demands an explanation by itself, wherefore we must cast 

 a glance at the political and social conditions of the time. 



Political radicalism of the Haeckelians 

 In Germany the seventies were a somewhat restless decade; the recent vic- 

 tories had certainly confirmed Bismarck in his power, but he nevertheless 

 had opponents in two directions: the Catholics, whose ultramontane politics 

 were regarded as a menace to the unity of the Empire, and the interna- 

 tional labour movement, which had recently found expression in the com- 

 munal riot in Paris, that had so scared the world, and not least Germany, 

 where some attempts against the lives of distinguished people were placed 

 to its account. In such circumstances the liberal-minded apprehended a fur- 

 ther reign of terror, and the friends of domestic peace still further social 

 upheavals. And Darwinism in particular, which indeed had from the begin- 

 ning been strikingly characterized as a theory of progress, through Haeckel's 

 boisterous attacks on the authorities of State and Church and through his 

 dogmatic description of the contrast between the doctrine of creation and 



