Abstract

The Aristotelian notion of a proper mixture is that of a homogeneous body potentially separable into a definite proportion of elements. Its relation to more modern chemical ideas is not without interest despite the success of modern atomic theory. But there is a fundamental conflict entailed by Aristotle’s two approaches to the characterisation of elements, one in terms of the properties they exhibit in isolation and another in terms of their role as constituents of compounds. Although one source of problems for Aristotle has been put aside in modern chemistry, it seems that the underlying tension remains an issue.