Critique of the Gotha Program (1875) is Karl Marx's sharp analysis of the draft program of the German Social Democratic Workers' Party, in which he critiques its concessions to bourgeois ideology and its lack of revolutionary clarity.

Marx argues for a scientific understanding of socialism, emphasizing that it must emerge from the contradictions of capitalism and transition through a dictatorship of the proletariat before achieving a stateless, classless society.

He also introduces the famous principle "from each according to his ability, to each according to his needs" for the higher phase of communism, distinguishing it from the transitional socialist phase where distribution is based on labor contribution.

Value, Price, and Profit (1865) is a foundational work by Karl Marx, presented as a lecture to the General Council of the First International, addressing debates about wages and their impact on capitalist production.

In it, Marx critiques the notion that workers' demands for higher wages harm the economy, instead arguing that the real issue lies in the exploitation of surplus value by capitalists.

He provides a concise explanation of labor value theory, surplus value, and the dynamics of profit, while advocating for workers to engage in class struggle to ultimately abolish the wage system and capitalism itself.

The Eighteenth Brumaire of Louis Bonaparte is a seminal work by Karl Marx that analyzes the 1851 coup d'état by Louis-Napoléon Bonaparte in France, drawing broader lessons about the relationship between class struggles, political leadership, and state power.

Marx dissects how historical conditions and class dynamics allowed a demagogue to exploit the fractured working class and reactionary bourgeoisie, crystallizing his theory of the state as a tool of class domination.