Adolf Remane is widely considered to have been one of the most influential German zoologists of the 20th Century, yet Ernst Mayr persistently characterized him as an idealistic morphologist, that is, a typologist unable to understand population genetics or indeed Darwinian theory. This stands in sharp contrast to Mayr's praise for Bernhard Rensch as one of the most important German contributors to the Modern Synthesis of evolutionary theory. Remane's style of scientific reasoning is analysed in his writings on microsystematics, ecology, comparative morphology and phylogenetics and found to be highly consistent throughout these varied fields of research, while differing fundamentally from the eminently statistical foundations of both population genetics and natural selection theory that were embraced by Mayr. A comparative analysis of Rensch's understanding of science in general, and biology in particular, shows him to share core values with Remane, both authors rooted in the Mandarin tradition of the German professoriate. Biographical and socio-political factors appear to have influenced Mayr's contrasting perception of Remane and Rensch, one that would influence later biologists and historians of science.