Johannes Rehmke, the German epistemologist, ontologist, and ethical philosopher, was born at Elmshorn in Schleswig-Holstein. He studied evangelical theology and philosophy at Kiel and Zürich from 1867 to 1871, receiving his doctorate in philosophy at Zürich in 1873. After some years as a high school teacher at St. Gallen, Rehmke was appointed unsalaried lecturer in philosophy at the University of Berlin in 1884. The following year he became professor of philosophy at the University of Greifswald, where he taught until 1921.

Theory of Knowledge

Rehmke did not assume the existence of two worlds: a world, only indirectly knowable, of transsubjective objects, and an immediately knowable world, with intrasubjective perceptions and the like as contents. Rather, he asserted the existence of directly knowable real objects. This epistemological monism was a consequence of his ontological dualism of two essentially different kinds of being. Physical (material) beings are spatially extended...