In lieu of an abstract, here is a brief excerpt of the content:Locke on the Knowledge of Material Things ROBERT FENDEL ANDERSON IT IS nOT John Locke's intention, in his Essay Concerning Human Understanding, to deal with matter and material substance nor with how these are able to affect the mind. These are considerations for natural philosophy; Locke counts himself rather among the moral philosophers. He does not propose, therefore, to meddle with the physical aspects of the mind, nor with (...) the physical production of sensations through the organs, nor with the production of ideas in the understanding, nor even with whether ideas depend upon matter for their source. He defers to the wisdom of such men as Boyle, Sydenham, Huygens and Newton in these considerations, and finds it "... ambition enough to be employed as an under-labourer in clearing the ground a little, and removing some of the rubbish that lies in the way to knowledge....,, 1 It is true that Locke's Essay is characterized chiefly not by an interest in matter and the mechanics of perception but rather by an interest in epistemology and in the ordering and assessment of our knowledge. Because of the very nature and emphasis of this epistemology, however, Locke finds that he must, from time to time, at least mention the nature of matter and how it affects us. Finally, it becomes apparent, certain changes or ambiguities in his point of view regarding the mode of our knowledge and its certainty are consequences of his understanding of matter. It is a demonstration of these elements of his doctrine, which seem not to have obtained the full attention of such scholars as Aaron, Fraser, and Gibson, that I shall attempt in this paper. Fundamentally, Locke's theory of matter appears to be that of Democritus and Epicurus. Like the Greek atomists, he conceives of matter as consisting of particles or corpuscles infinite in number. At least some of these are so minute as to be individually insensible, and probably he intends that all are, although, to my knowledge, he never states that this is so. In the aggregate, in any case, particles do constitute perceptible bodies. As for the Greeks, so also for Locke, the particles arc all extended, having size and shape. They are said also to possess motion or rest, although he takes care to say that matter cannot produce motion in itself,e Locke frequently mentions other properties as being "primary" or "really in" material things. Some of these are solidity, texture, cohesion of parts, situation, and number. Apparently some of these may be ranked under others since, as he 1"Epistle to the Reader," Vol. I, p. 14. All footnotes refer to passages in John Locke's An Essay Concerning Human Understanding, collated and annotated, with prolegomena, biographical, critical, and historical by Alexander Campbell Fraser, in two volumes (New York, Dover Publications, Inc., 1959). Large Roman numerals refer to books of the Essay; small Roman numerals refer to chapters of the books; Arabic numerals refer to sections of the chapters. 2 IV, x, 10. [205] 206 HISTORY OF PHILOSOPHY remarks, figure presupposes extension, and receiving or communicating motion through impact presupposes solidity. The influences of these particles upon one another are treated by Locke under the topic of "powers," a notion which includes in it some kind of "secret relation of parts." 3 The capacities in any substance to give alterations of primary qualities are active powers; the capacities to receive such alterations are passive powers. This alteration must be accomplished by impact or impulse since this, Locke says, is the only way in which bodies can be conceived to operate. Sensation in the percipient being then is to be understood as a special case of this impact of particles upon others. It is evident to Locke that from external obiects some motion must be conveyed by some parts of our bodies to the brain or seat of sensation to produce in our minds the particular ideas we have of these external objects. We are able by sight to perceive at a distance the primary qualities of bodies of observable size. Locke reasons that therefore "... some singly imperceptible bodies must come from them to the eyes, and thereby convey to... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:26. IN DEFENSE OF SECTION V: A REPLY TO PROFESSOR YOLTON Professor Yolton's article is especially valuable for its opening paragraphs on the writing done in the eighteenth century on the physiological basis of cognition. These provide a much-needed background to Hume's own remarks on the nature of perceptions.. It is both correct and helpful, I think, to understand any philosopher as a man of his own century. Professor (...) Yolton offers this article, in part at least, to differ with my interpretation given in "The Location, Extension, Shape, and Size of Hume's Perceptions." It seems to me, however, that this opening part of his article serves instead to lend support to mine. I have not said, by the way, that Hume believes that ideas are "brain impressions," since Hume has not used that phrase himself. Instead, I have merely provided evidence that Hume believes some perceptions have location, extension, shape and size; and I have pointed out an inconsistency that arises in this connection. Professor Yolton warns against taking Hume to intend, in saying that an idea represents its impression, that the idea is an image of the impression. I find, however, that Hume does assert that ideas are images: Those perceptions, which enter with most force and violence, we may name impressions.... By ideas I mean the faint images of these in thinking and reasoning.... (Tl) Again, in explaining memory: For what is the memory but a faculty, by which we raise up the images of paet perceptions? And as an image necessarily resembles its object.... (T260) At the end of his Part I, Professor Yolton concludes: (1) Hume never mentions the brain and the physiological processes. It is the mind or the soul which considers, conceives, imagines, remembers, thinks It seems to me not at all clear that Hume distinguishes soul 27. or mind from the brain, for he says: Bodily pains and pleasures...arise Originally in the soul, or in the body, whichever you please to call it.... (T276) And Hume certainly does describe the brain and its physiological processes on T60-61 and T185, as Professor Yolton himself later recognizes explicitly on his pages 12 and 16. An ambiguity arises regarding 'representation', Professor Yolton concludes, because Hume is writing in two languages in his account of ideas as representations : The difficulties of interpretation arise from Hume's application of quantitative terms to ideas - size, parts, divisibility. We have to balance this quantitative language of ideas by Hume's ascription of logical properties to ideas - truth, contradiction, possibility. When he speaks of ideas 'representing' things, to which language does 'representation' belong: to the quantitative or to the logical language? (6) I gather that Professor Yolton finds some sort of incompatibility between the "quantitative" characteristics of ideas and their "logical" ones; yet he offers no explanation why he finds them incompatible. More to the point, of course, is whether Hume himself regarded them as incompatible. I find he does not. Rather, it appears that it is the "quantitative" aspects of some ideas that permit them to be adequate representations, having the same "logical" properties as do objects. On T28 Hume has concluded that some ideas are very small: This however is certain, that we can form ideas, which shall be no greater than the smallest atom of the animal spirits of an insect a thousand times less than a mite.... Then on the following page he makes use of this conclusion to argue that ideas have the same "logical" properties as the objects they represent: Wherever ideas are adequate representations of objects, the relations, contradictions and 28. agreements of the ideas are all applicable to the objects ; and this we may in general observe to be the foundation of all human knowledge. But our ideas are adequate representations of the most minute parts of extension; and thro' whatever divisions and subdivisions we may suppose these parts to be arriv'd at, they can never become inferior to some ideas, which we form. The plain consequence is, that whatever appca rn impossible and contradictory upon the comparison of these ideas, must be really impossible and contradictory, without any farther excuse or evasion. (T29), Thus I... (shrink)