Economic and Philosophic Manuscripts of 1844
Written by Karl Marx between April and August 1844 while living in Paris. It was during this period that Marx and Engels would meet and become friends.
The first thing to realize in reading this (now-famous) text is that it is a very rough draft and was by no means intended for publication, as is. It represents Marx's first foray into analyzing political economy – a pursuit he'd undertake doggedly over the coming decades, leading ultimately to Capital.
Marx's research into political economy convinced him a larger published work was possible. On February 1, 1845, he signed a contract with Darmstadt publisher Carl Leske for a book to be titled 'A Critique of Politics and of Political Economy'. It was never completed for a variety of reasons and Leske cancelled the deal in September 1846, wanting to distance himself from the controversial political refugee.