Since structural descriptions rather than ostensive ones are required by the logic of the cultural sciences, the Platonic eidos as a regulative idea continues to play a creative role in establishing the formal unity of historical concepts. Paul Natorp, Troeltsch’s neo-Kantian contemporary and early proponent of the logicist thesis in Germany, first construed mathematical logic as a Platonistic search for the unconditioned in the form of absolutely foundational concepts or categories of thought. The hidden Platonism expressed in Troeltsch’s formal logic (...) of history is rather close to Natorp’s reading of the Platonic ideas as functions of knowledge, as methods, unities, and pure postulates of thought whose cognitive role is to be comprehensive, heuristic, and revelatory. Moreover, such characteristic 19th-century Hegelian histories of philosophical concepts as those of Adolf Trendelenburg and Gustav Teichmüller, or F. C. Bauer’s dialectical historical methodology of congruence and manifestation in ecclesiastical historicity, were Platonically oriented in that development meant fulfillment as abstract pristination [[sic]] or as the progressively emergent pure logic of historical ideas. The same climate of thought is expressed in F. H. Bradley’s version of the Identity of Indiscernibles and a Platonic-Hegelian ascent of concepts is present even later in Nicolai Hartmann’s neo-idealist treatment of the realization of concepts as "living spirit" in the progressive movement of research itself. (shrink)