The Logic of Propositions

Abstract

The following extract is taken from Galileo’s Dialogue concerning Two New Sciences. It deals with the question of whether or not bodies of unequal mass fall with unequal speeds. Galileo’s own demonstration that in fact they do not is often taken as the starting point for a history of modern science. It may appropriately serve to introduce a discussion of the part which logic has had to play in science. The dialogue takes place between three people — Simplicio, Sagredo and Salvator.