Pluralism and the unity of science: physics and political epistemology in Cassirer's phenomenology of knowledge

In this article, we analyse how Ernst Cassirer's approach of a phenomenology of knowledge deals with the general question of disunity in science and society. By elaborating on the concept of functional unity, which presupposes difference, Cassirer's work helps to revise foundational concepts of modern science and society, such as pluralism and truth. Relating Cassirer's approach to the current interest in political epistemology, we show the implications of Cassirer's theory of knowledge and analyses of modern science, particularly physics. In these analyses, Cassirer carves out the relational logic of scientific knowledge and its consequences on epistemological and ethico-political levels. While this logic of relations relativises absolute claims on either level, it entails its distinct normative criteria as elements of the scientific ideal. Cassirer's project defends this ideal and thus can simultaneously defend plurality in science (including the humanities) in terms of methods, perspectives and aims, and preserve the unity of science as a normative ideal and symbolic form in constant interaction with other forms. Thus, Cassirer's pluralism must be distinguished from mere historicist or relativist conceptions.