Abstract

Leibniz’s binary numeral system is generally studied for its arithmetical relevance, but the analysis of several unpublished manuscripts shows that from the very beginning Leibniz also envisaged a new form of algebra in the context of dyadics based on the idea that its letters can only express numbers that are either 1 or 0. In this paper, I shall present the most notable results of this binary algebra: the determination of the algorithm for the expansion of squares and the development of the positional notation used to express any possible number. These achievements explain the priority of dyadics over any other numeral system in Leibniz’s mind and his impressive work on the classification of numbers which was facilitated by tools and notions which were only accessible to him at that time.