 Almost all major philosophers have discussed the concept of substance and an attempt to cover all of this history would be unwieldy. The selection made will concentrate on those philosophers in whom the broadly analytic tradition has shown most interest. First we shall look at the development of the concept in the ancient world, culminating in the work of Aristotle. His account dominated debate through the Middle Ages and until the early modern period. We shall consider various rationalist and empiricist treatments of the concept. Locke’s contribution will be considered in especial detail because so much contemporary discussion is inspired (as we shall see in  section 3)  by an Aristotle-Locke nexus.