The notion that Marx neither understood nor advocated the use of mathematics is a persistent one. His interest in both commercial and abstract mathematics spanned more than two decades however, and culminated in two "contributions" to the foundations of the calculus: "On the Concept of the Differential" (1881). A detailed examination of these and other technical notebooks suggests that Marx's economics both motivated and informed his studies in mathematics and that these, in turn, influenced his understanding of economic phenomena.
