Studies of the relationship between philosophy and biology in the twentieth century have tended to focus on the more dominant reductionist trends in the subject/science. Although there is a body of work examining alternative positions in biology, it is still somewhat small. Within this work it is acknowledged that, although in a minority, biologists in these alternative positions were often very influential in their chosen field and their impact can still be seen today. Common issues at stake for these biologists were the status of reductionism, holism, neo-idealism, materialism and the relationship of the whole to the parts. This work by Esposito is a welcome addition to the corpus of such literature.

Esposito identifies the impact of Kantian thought on various influential biologists in the United Kingdom and the USA from 1890 to 1945. To reconstruct this Kantian tradition he draws connections between and within these generations through their philosophical inclinations, the influence of Kantian/neo-Kantian mentors in their chosen field, the practical traditions in which they were taught in their formative years, and the role some played in setting up institutions. As a comparative study he highlights, where relevant, the various conceptual, epistemological and methodological differences that delineate both various biologists' uses of the Kantian tradition and their consequent objections to the major trend of mechanistic materialism (perceived as reductionism).

During the nineteenth century the influence of Kant in biology in Britain often came via K.E. von Baer and Georges Cuvier. Esposito traces these connections through such figures as the physician and comparative anatomist Joseph H. Green, the comparative anatomist Richard Owen (whose Kantian influences included Cuvier and Green), and the physiologist W.B. Carpenter. This Kantian community produced an organismic and teleological biology that represented the conservative orthodoxy in Britain. By the late nineteenth century this tradition was increasingly eclipsed by Darwinian biology and Lamarckian materialism, so much so that there was no direct transmission of it from the British Kantians to the next generation of British biologists. However, the idea persisted that to do good biology required familiarity with German biology. This influenced, for example, the embryologist Francis Maitland Balfour and the physiologist Michael Foster. Through their teaching and publications it is likely that the Kantian embryological tradition was absorbed by a number of the new generation (examples include Gavin de Beer, James Gray, E.W. MacBride, E.S. Russell and D'Arcy Wentworth Thompson). John Scott Haldane, a prominent neo-Kantian biologist, arrived at his position by a different route that nonetheless involved German biology. For the United States, Esposito examines the roles of Charles Otis Whitman, F.R. Lillie, E.E. Just, W.E. Ritter and C.M. Child. Both Whitman and Ritter are examples of how the transmission and diffusion of the Kantian organicist tradition was less complex. An important part of their influence lay in running institutions (and in Whitman's case scientific journals) that fostered an organismal approach to biology.

This brings us to Esposito's choice of the term ‘Romantic biology’ to label this movement. Although obviously attempting to place his study in a wider historical context, he struggles to define Romanticism, admitting that this has been problematic for a long time; the definition in his introductory section ends up somewhat nebulous. However, in the next few chapters, the key elements for Esposito of the Romantic tradition are easily identifiable as they repeatedly appear in various combinations dependent on particular biologists' interests. These elements include ‘denial of vitalism and mechanism; the acceptance of living organisation as a postulate; the use of teleological explanations; the complex dialectics between function and structure; the essential organic relation of parts to the whole; and the fundamental interrelatedness of organism and environment’ (p. 84).

In his concluding chapter Esposito examines various factors in the decline of Romantic biology whilst noting that there have been occasional revivals. He moves through Romantic biology's connections to vitalism, the taint of association with ‘totalitarian philosophies', Rockefeller Foundation funding for approaches to biology based on known successful physical methods (the ‘protein paradigm’), the success of the Morgan school's chromosomal theory of heredity opening the door to research on the physical basis of heredity, and the changes in politics and ideology in the Cold War years when ideas of group conflict and competition displaced those of cooperation. This chapter relies heavily on the work of other historians and Esposito does not draw any strong conclusions as to which factors have been more important to his story. Perhaps this will come later with further work on this subject. In the meantime Esposito's summary is useful and thought-provoking.