ABSTRACT
This part introduction presents an overview of the key concepts discussed in the subsequent chapters. The part argues that John Locke uses 'substance' differently in Essay II.xxvii than he does elsewhere in the Essay. In Book II, chapter xxvii of his Essay Concerning Human Understanding, Locke addresses these issues about identity and change. Two claims that Locke makes while explaining his views about these issues are particularly puzzling. One puzzle involves changes to an object. The second, and related, puzzle is about Locke's use of the word 'substance.' Usually in the Essay it appears that Locke counts people as substances, as individual things that exist over time and have features, rather than as properties or qualities or events or any of the other sorts of things there seem to be in the world.
