The controversy over spontaneous generation and the theory of evolution was part of the broader issue of the nature of life. It was the vitalists, who had originally accepted the doctrine of heterogenesis, who now were forced to reject abiogenesis. Their commitment to the view that life was unique and autonomous was so strong that, once the link between evolution and the abiogenetic origin of life had been made, they were almost constrained to reject evolution. It is not surprising that (...) one finds this extreme position among German scientists, for it was only in Germany that the strong connection had been made. In Britain, with its strong empirical tradition, the theory of evolution was never completely tied to the doctrine of abiogenesis.Many nonvitalistic biologists were equally committed to the view that there was a gradation between the living and the nonliving, and saw in the doctrine of evolution a vindication of these views. To many of this school, abiogenesis was an a priori necessity requiring no empirical proof. If they sought for any empirical justification for their views on abiogenesis, one feels that such proof was never of great importance to them. Many—particularly the Germans—regarded those who denied abiogenesis because of the lack of proof to be guilty of following an outdated methodology: “that modern scientists still put so uncommon value on the inductive proof of spontaneous generation, is the clearest indication that few place confidence in the first principle of the theory of knowledge.” To them an acceptance of abiogenesis was necessary “in order to understand nature according to the laws of causality.” 105. (shrink)