Dialogues Concerning Natural Religion is a philosophical work by the Scottish philosopher David Hume. Through dialogue, three philosophers named Demea, Philo, and Cleanthes debate the nature of God's existence. While all three agree that a god exists, they differ sharply in opinion on God's nature or attributes and how, or if, humankind can come to knowledge of a deity.

In the Dialogues, Hume's characters debate a number of arguments for the existence of God and arguments whose proponents believe through which we may come to know the nature of God. Such topics debated include the argument from design—for which Hume uses a house—and whether there is more suffering or good in the world (the argument from evil).

Nearly two years before his powerful Communist Manifesto, Marx (1818—1883) co-wrote The German Ideology in 1845 with friend and collaborator Friedrich Engels, expounding a new political worldview, including positions on materialism, labor, production, alienation, the expansion of capitalism, class conflict, revolution, and eventually communism.

They chart the course of "true" socialism based on G. W.F. Hegel's dialectic, while criticizing the ideas of Bruno Bauer, Max Stirner and Ludwig Feuerbach. Marx expanded his criticism of the latter in his now famous Theses on Feuerbach, found after Marx's death and published by Engels in 1888.

Introduction to the Critique of Political Economy, also found among the posthumous papers of Marx, is a fragment of an introduction to his main works. Combining these three works, this volume is essential for an understanding of Marxism.