THE PROXIMATE/ULTIMATE DISTINCTION IN THE MULTIPLE CAREERS OF MAYR,ERNST

Ernst Mayr's distinction between ''ultimate'' and ''proximate'' causes is justly considered a major contribution to philosophy of biology. But how did Mayr come to this ''philosophical'' distinction, and what role did it play in his earlier ''scientific'' work? I address these issues by dividing Mayr's work into three careers or phases: I);Mayr the naturalist/researcher, 2) Mayr the representative of and spokesman for evolutionary biology and systematics, and more recently 3) Mayr the historian and philosopher of biology. If we want to understand the role of the proximate/ultimate distinction in Mayr's more recent career as a philosopher and historian, then it helps to consider his earlier, use of the distinction, in the course of his research, and in his promotion of the professions of evolutionary biology and systematics. I believe that this approach would also shed light on some other important ''philosophical'' positions that Mayr has defended, including the distinction between ''essentialism: and ''population thinking.''