This volume is the first of three which will contain all of Locke's extant writings on philosophy which relate to An Essay Concerning Human Understanding, other than those contained in volumes of the Clarendon Edition of John Locke such as the Correspondence. The book contains the two earliest known drafts of the Essay, both written in 1671, and provides for the first time an accurate version of Locke's text together with a record of virtually all his changes, in notes at the foot of each page.