ABSTRACT
Locke's is probably the earliest theory of abstraction still to receive critical discussion as a part of the normal philosophy curriculum in universities in the English-speaking world. Yet, as disputes about its interpretation and vulnerability to Berkeley's famous criticisms bear witness, it is easy to miss the meaning of the theory and its point unless it is located in the long-standing context of debate. In fact, the notion of abstraction was common property in seventeenth-century philosophy. It was associated in Aristotelian philosophy with the notion of a distinction of thought or reason, such as the logical distinctions between form and matter, between species and genus, and between substance and accident. More relevant to our present concerns, however, is its connection with the doctrine that the active intellect forms universal 'intelligible species' from particular images in the imagination, images deriving in turn from 'sensible species' intromitted in sense experience.
