Georges Dicker here provides a commentary on John Locke's masterwork, An Essay Concerning Human Understanding-the foundational work of classical Empiricism. Dicker's commentary is an accessible guide for students who are reading Locke for the first time; a useful research tool for upper-level undergraduate and graduate students; and a contribution to Locke scholarship for professional scholars. It is designed to be read alongside the Essay, but does not presuppose familiarity with it.