In this study we have seen that a small international community of scientists were committed to formulating an anti-mechanistic, anti-reductionist, holistic biology. We have learned that their approach and ideas were not a result of a new paradigm emerging in the twentieth century, but were a complex reformulation or re-appropriation of an old tradition whose original source was Kant and the subsequent Romantic tradition. In addition, we have seen that such a reformulation underpinned an alternative form of biology, an alternative to the gene-centric views of heredity, development and evolution that were gaining momentum in the 1930s with the synthesis of neo-Darwinism and Mendelism. Such an alternative view, with all its variations and idiosyncrasies, saw developmental biology as the privileged science for the understanding of speciation. Evolution could not be conceived as change in the gene frequency in populations, but as systemic changes happening during ontogeny. We have also found that this tradition, as transplanted and translated in England and the United States, acquired a specific and contingent political meaning and force. The notion of the organism as an irreducible system of interdependent causes and effects worked as a powerful political metaphor which could inspire a more equitable, harmonious and efficient society. At the same time, mechanistic and reductionist approaches, exemplified in Mendelism and Weismannism, came to be associated with capitalist ideology and a conception of society as comprising an aggregate of selfish individuals in constant competition.

At its height, the Romantic bio-philosophical tradition reconstructed here commanded the allegiances of some outstanding scientists working at prestigious institutions. But it is a tradition in need of reconstruction precisely because it subsequently went into decline, experiencing revivals thereafter. Probably one of the most interesting and eloquent examples of the tradition's decline is the Scripps Marine Association.