Abstract

The later Wittgenstein holds that the sole function of mathematical propositions is to determine the concepts they invoke. In the paper this view is discussed by means of a single example: Wittgenstein's investigation of the concept of a regular heptagon as used in Euclidean geometry (i.e., the Euclidean constructiongame with rulerand compass) andinCartesian analytic geometry. Going on from some well-known passages in Wittgenstein's Lectures on the Foundations of Mathematics, and completing these passages, it is shown that Wittgenstein'sview makes perfectly good sense and can be very well defended.