The conquest of vitalism or the eclipse of organicism? The 1930s Cambridge organizer project and the social network of mid-twentieth-century biology.

In the 1930s, two concepts excited the European biological community: the organizer phenomenon and organicism. This essay examines the history of and connection between these two phenomena in order to address the conventional 'rise-and-fall' narrative that historians have assigned to each. Scholars promoted the 'rise-and-fall' narrative in connection with a broader account of the devitalizing of biology through the twentieth century. I argue that while limited evidence exists for the 'fall of the organizer concept' by the 1950s, the organicism that often motivated the organizer work had no concomitant fall--even during the mid-century heyday of molecular biology. My argument is based on an examination of shifting social networks of life scientists from the 1920s to the 1970s, many of whom attended or corresponded with members of the Cambridge Theoretical Biology Club (1932-1938). I conclude that the status and cohesion of these social networks at the micro scale was at least as important as macro-scale conceptual factors in determining the relative persuasiveness of organicist philosophy.