Wilhelm Troll (1897 - 1978): idealistic morphology, physics, and phylogenetics

Idealistic morphology as articulated by the botanist Wilhelm Troll, the main target of the critique voiced by the early phylogeneticists, was firmly embedded in its contemporary scientific, cultural, and political context. Troll appealed to theoretical developments in contemporary physics in support of his research program. He understood burgeoning quantum mechanics not only to threaten the unity of physics, but also the validity of the principle of causality. Troll used this insight in support of his claim of a dualism in biology, relegating the causal-analytical approach to physiology, while rejuvenating the Goethean paradigm in comparative morphology. This embedded idealistic morphology in the völkisch tradition that characterized German culture during the Weimar Republic and its aftermath. In contrast, the contemporary phylogeneticists anchored their research program in the rise of logical positivism and in Darwin's principle of natural selection. This, in turn, brought phylogenetic systematists of the late 1930s and early 1940s into the orbit of national-socialist racial theory and eugenics. In conclusion, the early debate between idealistic morphologists and phylogenetic systematists was not only ideologically tainted, but also implied a philosophical impasse that is best characterized as a conflict between the Goethean and Newtonian paradigm of natural science.