"This work is a testimony with regard to the method employed by Marx and Engels in arriving at their philosophical conclusions. It is the statement of the philosophical foundations of modern socialism by one who helped to lay them; it is an old man's account of the case upon the preparation of which he has spent his entire life, for, this work, short as it is, represents the results of forty years of toil and persevering effort." [Austin Lewis] --- "Marx has died without either of us having had an opportunity of coming back to the antithesis ... We never came back to Feuerbach, who occupies an intermediate position between the philosophy of Hegel and our own ... Under these circumstances a short, compact explanation of our relations to the Hegelian philosophy, of our going forth and departure from it, appears to me to be more and more required. And just in the same way a full recognition of the influence which Feuerbach, more than all the other post-Hegelian philosophers, had over us, during the period of our youthful enthusiasm, presents itself to me as an unendurable debt of honor ... On the other hand, I have found in an old volume of Marx the eleven essays on Feuerbach printed here as an appendix. These are notes hurriedly scribbled in for later elaboration, not in the least degree prepared for the press, but invaluable, as the first written form, in which is planted the genial germ of the new philosophy." [Friedrich Engels] Friedrich Engels (English /ˈɛŋɡəlz/ or /ˈɛŋəlz/; German: [ˈfʁiːdʁɪç ˈɛŋəls]; 28 November 1820 - 5 August 1895) was a German philosopher, social scientist, journalist and businessman. He founded Marxist theory together with Karl Marx. In 1845 he published The Condition of the Working Class in England, based on personal observations and research in Manchester. In 1848 he co-authored The Communist Manifesto with Karl Marx, though he also authored and co-authored (primarily with Marx) many other works, and later he supported Marx financially to do research and write Das Kapital. After Marx's death, Engels edited the second and third volumes. Additionally, Engels organised Marx's notes on the "Theories of Surplus Value," which he later published as the "fourth volume" of Capital. He has also made contributions to family economics.