From Mephistopheles to Isaiah: Jacques Loeb, technical biology and war.

In 1917, the German-American scientist Jacques Loeb (1859-1924) published a short essay, entitled 'Biology and War', that summarized his disagreement with World War I. He was deeply saddened by the break-up of the international scientific community as a consequence of the actions of bellicose politicians. These actions were in direct opposition to his efforts to promote social reform, mechanistic biology and scientific internationalism. The aim of this paper is to examine Loeb's activities aimed at these efforts before, during and after the war. It attempts to explain how Loeb's scientific work was formed, what was special about it and why it was both successful and attacked. Particular emphasis is placed on how Loeb reacted to the War and the subsequent forced disintegration of his international scientific network. Loeb's attempts to integrate his interpretation of biology into post-war Europe's approach to the life sciences is analysed in connection with his social commitment. It is argued that his emigration to the USA, the circumstances of World War I, the reaction of his German colleagues to it and the demolition of the international scientific community changed: (1) Loeb's feelings towards his old home; (2) the direction of his scientific endeavours; and (3) his engagement in science politics. His correspondence with eminent scientists from all over the world serves as a key to Loeb's efforts in the context of the social elements of scientific networks and perceptions.