In 1695 John Locke published The Reasonableness of Christianity, an enquiry into the foundations of Christian belief. He did so anonymously, to avoid public involvement in the fiercely partisan religious controversies of the day. This is the first critical edition of the Reasonableness: for the first time an authoritative annotated text is presented, with full information about sources, variants, amendments, and the publishing history of the work. Also provided in the editorial notes are cross-references, references to other works by Locke, definitions of terms, and other information conducive to an understanding of the text.