A Contribution to the Critique of Political Economy was first published in 1859. The book is mainly an analysis of capitalism and quantity theory of money, achieved by critiquing the writings of the leading theoretical exponents of capitalism at that time: these were the political economists, nowadays often referred to as the classical economosts; Adam Smith (1723–90) and David Ricardo (1772–1823) are the foremost representatives of the genre.
Much of the Critique was later incorporated by Marx into his magnum opus, Capital (Vol 1), published in 1867.