Written in 1686, Discourse on Metaphysics is one of the most important and widely published works in the history of philosophy. This translation and commentary by Christopher Johns has much new to offer. Based extensively on the Akademie edition this is the first truly scholarly translation. Also included is historical and philosophical context, detailing Leibniz's activities during 1685 and 1686, and several letters previously unpublished in English. These letters and texts illuminate important themes found in the Discourse and shed light on the intellectual context of the time which will be of particular interest to scholars and teachers of Leibniz.