A landmark of Enlightenment thought, Hume's An Enquiry Concerning Human Understanding is accompanied here by two shorter works that shed light on it: A Letter from a Gentleman to His Friend in Edinburgh, Hume's response to those accusing him of atheism, of advocating extreme skepticism, and of undermining the foundations of morality; and his Abstract of A Treatise of Human Nature, which anticipates discussions developed in the Enquiry.

• Prolegomena to Any Future Metaphysics: and the Letter to Marcus Herz, February 1772
• Meditations on First Philosophy: In Which the Existence of God and the Distinction of the Soul from the Body Are Demonstrated
• An Essay Concerning Human Understanding
• Descartes: Meditations on First Philosophy: With Selections from the Objections and Replies (Cambridge Texts in the History of Philosophy)
• Discourse on Method and Meditations on First Philosophy, 4th Ed.