The book by Dr. of Philosophy N. I. Lapin introduces the reader to the life and work of the young Marx, describing how his worldview developed—from idealism to materialism, and from revolutionary democrats to communism. Unfolding Marx’s complex spiritual evolution, the author shows that its main driving force was the connection between the thinker’s theoretical views and political practice: the combination of criticizing the old world with the struggle to reorganize it. In this regard, the book also sheds light on questions of ideological struggle surrounding the legacy of the young Marx. The third edition of the book (the second came out in 1976 and received the State Prize of the USSR) is supplemented with materials accounting for new publications of works by the founders of Marxism. The book is intended for everyone studying Marxist-Leninist philosophy.