Two foundational works of modern political thought, Economic and Philosophic Manuscripts of 1844 and The Manifesto of the Communist Party reveal Karl Marx and Frederick Engels at crucial moments in the development of socialist theory, social criticism, and revolutionary philosophy. In Economic and Philosophic Manuscripts of 1844, Marx examines labor, private property, alienation, money, and the condition of the worker under capitalism. Written early in his career and not published during his lifetime, the manuscripts show Marx wrestling with philosophy, economics, and human freedom in a language still deeply shaped by Hegel, Feuerbach, and the moral urgency of nineteenth-century social upheaval. Here Marx develops one of his most influential ideas: that modern labor can estrange human beings from their work, from the products they create, from one another, and from their own human potential. The Manifesto of the Communist Party, written by Marx and Engels and first published in 1848, is one of the most famous political documents ever written. Concise, forceful, and historically sweeping, it presents a theory of class struggle, the rise of the bourgeoisie, the revolutionary role of the proletariat, and the demand for a radical transformation of social and economic life. Together, these works offer readers a powerful introduction to Marxist thought, combining philosophical analysis with political urgency and remaining essential for understanding modern debates over capitalism, labor, class, ideology, and revolution.