It would be worthwhile to pursue the themes we have discussed to the present time. However I close with World War I. Another book (and another decade's work) would be required to do justice to the fascinating period after Versailles, and to energetic thinkers such as Raymond Pearl, Margaret Mead, Maurice Davey, Quincy Wright, Konrad Lorenz, Eric Fromm, E. A. Wilson and the sociobiologists. The lack of British names reflects their diminished contribution to a biological debate that British scientists largely pioneered. It would be interesting to gauge the extent to which the trauma of the First World War experience helped depopularise instinct theory, and accelerate the trend to behaviourism and ‘culture theory’ in bio-psychology and the social sciences generally. By comparing and contrasting national responses to the issue of war and human aggression (for example, Britain compared with the United States), one would hopefully glean deeper insights into the interaction between science and culture. That interaction would be dramatically illustrated also by analysis of the impact of Nazism and Stalinism upon biological discourse. For the moment, a few concluding reflections upon the present endeavour seem in order.

This study has attempted to trace the manifold implications of Darwin's theories for the debate over war and peace. It is suggested that, while Darwinism was translatable into almost every available idiom of political and social discourse, its usage in justifying war and generating a violent image of Homo pugnax has been exaggerated in the historical literature.