Abstract

The striving for a unification of the sciences, which characterises Hermann von Helmholtz's scientific work throughout, was influential for the neokantian movement that followed him. It concentrated on mathematical physics, was oriented towards a mechanistic world view and faced a process of increasing hypothetization. Starting points were his formulation of the law of energy conservation and his speech "Über das Sehen des Menschen" in 1855, which was regarded as a significant impulse for the renewed turn to Kant. In this speech, Helmholtz substantiated his lifelong thesis of free will and the autonomy of thought. End points were his ideas on monocyclic systems and the principle of the least action. The physical efforts towards a formally founded unity were accompanied by manifold of synthetizations in special fields such as optics, acoustics and electrodynamics. The quest for unification was in tension with the specialisation of the sciences, which was already progressing at the time, and found its limit in the difference to the humanities recognised by Helmholtz and still relevant today.