ABSTRACT
Jacob Klein's account of the original phenomenon of formalization accomplished by the innovators of modern mathematics, when they transformed the Greek arithmos into the modern concept of number, and his suggestion that the essential structure of this historically located formalization has become paradigmatic for the concept formation of non-mathematical concepts, is situated within the context of Husserl's and Heidegger's understanding of formalization. Burt Hopkins show that Klein's philosophical achievement consists in his account of formalization and the formality of the concepts that it generates as being ungraspable so long as thinking approaches them as something is knowable, independent of its historicity. Klein was also a man of immense formal learning, who at one time had prepared himself to become qualified to teach in the German university system. Eva Brann, recently confirmed this, as she traces Klein's distancing himself from the activity of a scholar to the greater value he came to place in the eliciting of thought from the young.
