Ideas and Knowledge in Seventeenth-Century Philosophy

Ideas and Knowledge in Sewnteenth-Century Philosophy JOHN W. YOLTON THOMASREm's Essays on the Intellectual Powers of Man (1785)t contains one of the earliest attempts to trace the history of the term 'idea' in seventeenth- and eighteenthcentury philosophers. Reid opposed the philosophic use of that term, as the object and not the act of thought, to its use in popular and ordinary language. In this latter use "idea signifies the same thing as conception, apprehension, notion. To have an idea of anything is to conceive it" (p. 16). In a later passage, Reid presents this popular sense of 'idea' even more forcefully. To think of a thing, and to have a thought of it; to believe a thing, and to have a belief of it; to see a thing, and have a sight of it; to conceive a thing, and to have a conception, notion, or idea of it, are phrases perfectly synonymous. In these phrases, the thought means nothing but the act of thinking; the belief, the act of believing; and the conception, notion, or idea, the act of conceiving. To have a clear and distinct idea, is, in this sense, nothing else but to conceive the thing dearly and distinctly. When the word idea is taken in this popular sense, there can be no doubt of our having ideas in our minds. To think without ideas would be to think without thought, which is a manifest contradiction. (p, 174) The contrast which Reid draws repeatedly in his survey of the history of the term 'idea' is doubly important for an understanding of the theories of knowledge and cognition in seventeenth-century philosophy. It is important, firstly, because it echoes many of the debates between philosophers in the seventeenth century and, secondly, for the way it poses the question of direct realism. For Reid, the philosopher's 'idea' was a fiction which, if real, would mean that "we perceive not external objects immediately, and that the immediate objects of perception are only certain shadows of the external objects" (p. 133). Reid thinks we see objects directly, but when he tries to formulate what it is to think of or to cognize an external object, his use of the popular and common sense form of 'idea' and 'notion' brings him close to the views held by Locke and by Arnauld. He is prepared to give credit to Arnauld for coming close to the proper view of cognition. He even concedes that on occasion Locke seems to wish to embrace that view, but overall Locke is classed among the philosophers holding to the fictional view. The standard reading of Locke as a representationist needs emendation. I have recently attempted an extended analysis of his theory of knowledge on this question, offering a variety of reasons why Locke's text does not support reading him as Reid and many others have3 Besides the general claim that Locke was consciously trying to develop a 1 References to this work of Reid are to the 1786 (Dublin) two-volume edition. All references are to volume 1. Locke and the Compass of Human Understanding (1970), chap. 5. An earlier and slightly different version of this chapter appeared in YowettPapers, 1968-69, ed. by Khanbhai, Katz, and [145] 146 HISTORY OF PHILOSOPHY theory of "knowledge consistent with observational science, I called attention to two passages in the Essay which, I think, clearly indicate I.ocke's explicit recognition and acceptance of the Cartesian notion of the objective existence of objects in the understanding . Locke introduces the term 'idea' (in 1.1.8) as expressing "whatever is meant by phantasm, notion, species." This vocabulary is taken from a long tradition behind Descartes, going back through St. Thomas to Aristotle) The intelligible species is the object known, as it exists in the understanding. The formal or actual reality of a physical object (e.g., a stone, the sun) is its existence in space. The same object's objective existence is its existence in the understanding when it is known. The distinction between formal and objective existence is found in Descartes' Meditation III. In his "Epistle to the Reader," Locke says of a determinate or determined idea...