This paper discusses some of C. S. Peirce’s insights about continuity in his attempt to grasp the concept of the mathematical continuum. After a discussion of his earlier notions which he called ‘Kanticity’ and ‘Aristotelicity’ we arrive at his later belief that a continuum is rather a system of potential points. In his mature views, Peirce grasps a continuum as “a whole range of possibilities” without points at all. In the sequel, we turn to take into account some of Leibniz’s (...) attempts to deal with continuity and the continuum and we compare Peirce and Leibniz’s approaches detecting certain impressive similarities and differences. (shrink)

The aim of this paper is to analyze Dimitry Gawronsky’s doctrine of actual infinitesimals. I examine the peculiar connection that his critical idealism establishes between transcendental philosophy and mathematics. In particular, I reconstruct the relationship between Gawronsky’s differentials, Cantor’s transfinite numbers, Veronese’s trans-Archimedean numbers and Robinson’s hyperreal numbers. I argue that by means of his doctrine of actual infinitesimals, Gawronsky aims to provide an interpretation of calculus that eliminates any alleged given element in knowledge.

The metaphysical concept of continuity is important, not least because physical continua are not known to be impossible. While it is standard to model them with a mathematical continuum based upon set-theoretical intuitions, this essay considers, as a contribution to the debate about the adequacy of those intuitions, the neglected intuition that dividing the length of a line by the length of an individual point should yield the line’s cardinality. The algebraic properties of that cardinal number are derived pre-theoretically from (...) the obvious properties of a line of points, whence it becomes clear that such a number would cohere surprisingly well with our elementary number systems. (shrink)