REID 351 his revulsion from the sceptical conclusions of Hume. In several passages of his writings he expressly dates his philosophical awakening from the appearance of the Treatise of Human Nature. " I acknowledge," he says in the dedication of the Enquiry, " that I never thought of calling in question the principles commonly received with regard to the human understanding until the Treatise of Human Nature was published in the year 1739. The ingenious author of that treatise upon the principles of Locke who was no sceptic hath built a system of scepticism which leaves no ground to believe any one thing rather than its contrary. His reasoning appeared to me to be j ust ; there was, therefore, a necessity to call in question the principles upon which it was founded, or to admit the conclusion." Reid thus takes Hume's scepticism as, on its own showing, a reductio ad impossibile of accepted philosophical principles, and refuses, accordingly, to separate Hume from his intellec- tual progenitors. From its origin in Descartes and onwards through Locke and Berkeley, modern philosophy carried with it, Reid contends, the germ of scepticism. That scepticism, " inlaid in it and reared along with it," Hume did but bring to light. Embracing the whole philosophic movement under the name of " the Cartesian system," Reid detects its Trpwrov if/evBo? in the unproved assumption shared by these thinkers "that all the objects of my knowledge are ideas in my own mind." This doctrine or hypothesis he usually speaks of as " the ideal system " or "the theory of ideas"; and to it he opposes his own analysis of the act of perception. In view of the results of this analysis, Reid's theory (and the theory of Scottish philosophy generally) has been dubbed natural realism or natural dualism in contrast to theories like subjective idealism and materialism or to the cosmothetic idealism or hypothetical dualism of the majority of philosophers. But this is unduly to narrow the scope of Scottish philosophy, which does not exhaust itself, as it is sometimes supposed to do, in uncritically reasserting the independent existence of matter and its immediate presence to mind. The real significance of Reid's doctrine lies in its attack upon the principles which Hume explicitly lays down as the alpha and the omega of his system, viz., the principles that all our perceptions are distinct existences, and that the mind never perceives any real connexion among distinct exist- ences (cf. Appendix to the third volume of the Treatise, 1740). It is here that the danger of " the ideal system " really lies in its reduction of reality to " particular perceptions," momentary or "perishing" existences essen- tially unconnected with each other. If the ultimate elements of experience are unrelated units or sense- atoms, called impressions, then it only remains to be shown, as Hume attempts to show, how the illusion of supposed necessary connexion arises. But Reid meets this scepticism by combating the principle on which it is based. In logical language, he denies the actuality of the abstract particular : unrelated impressions and ideas nowhere exist. The unit of knowledge is not an isolated impression but a judgment ; and in such a judgment is contained, even initially, the reference both to a permanent subject and to a permanent world of thought, and, implied in these, such judgments, for example, as those of existence, substance, cause and effect. Such principles are not derived from sensation, bujb are " suggested " on occasion of sensation, in such a way as to constitute the necessary conditions of our having perceptive experience at all. Thus we do not start with "ideas," and afterwards refer them to objects ; we are never restricted to our own minds, but are from the first immediately related to a permanent world. Reid has a variety of names for the principles which, by their presence, lift us out of subjec- tivity into perception. He calls them "natural judgments," "natural suggestions," "judgments of nature," "judg- ments immediately inspired by our constitution," "prin- ciples of our nature," "first principles," "principles of common sense." The last designation, which became the current one, was undoubtedly unfortunate, and has conveyed to many a false impression of Scottish philosophy. It has been understood as if Reid had merely appealed from the reasoned conclusions of philosophers to the unreasoned beliefs of common life. The tirades of men like Beattie and Oswald, and many unguarded utterances of Reid himself, lent countenance to this notion. But Reid's actions are better than his words ; his real mode of procedure is to redargue Hume's conclusions by a refutation of the premises inherited by him from his predecessors. For the rest, as regards the question of nomenclature, Reid everywhere unites common sense and reason, making the former "only another name for one branch or degree of reason." Reason, as judging of things self-evident, is called common-sense to distinguish it from ratiocination or reasoning. And in regard to Reid's favourite proof of the principles in question by reference to " the consent of ages and nations, of the learned and unlearned," it is only fair to observe that this argument assumes a much more scientific form in the Essays, where it is almost identified with an appeal to " the structure and grammar of all languages." "The structure of all languages," he says, "is grounded upon common sense." To take but one example, " the distinction between sen- sible qualities and the substance to which they belong, and between thought and the mind that thinks, is not the invention of philosophers ; it is found in the structure of all languages, and therefore must be common to all men who speak with understanding" (Hamilton's Reid, pp. 229 and 454). The principles which Reid insists upon as everywhere present in experience evidently correspond pretty closely to the Kantian categories and the unity of apperception. Similarly, Reid's assertion of the essential distinction between space or extension and feeling or any succession of feelings may be compared with Kant's doctrine in the ^Esthetic. "Space," he says, "whether tangible or visible, is not so properly an object [Kant's " matter "] as a neces- sary concomitant of the objects both of sight and touch." Like Kant, too, Reid finds in space the source of a necessity which sense, as sense, cannot give (Hamilton's Reid, 323). In the substance of their answer to Hume, the two philosophers have therefore much in common. But Reid lacked the art to give due impressiveness to the important advance which his positions really contain. Although at times he states his principles with a wonder- ful degree of breadth and insight, he mars the total effect by frequent looseness of statement, and by the amount of irrelevant psychological matter with which they are overlaid. And, if Kant was overridden by- a love of formal completeness and symmetry, Reid's extreme indifference to form and system is an even more danger- ous defect in a philosopher. It has also to be admitted that the principles frequently appear in Reid more as matter of assertion than as demonstrated necessities for the constitution of experience. The transcendental deduc- tion, or proof from the possibility of experience in general, which forms the vital centre of the Kantian scheme, is wanting in Reid; or, at all events, if the spirit of the proof is occasionally present, it is nowhere adequately stated and emphasized. But, when these defects are ackno wledged, Reid's insistence on judgment as the unit of knowledge and his sharp distinction between sensation and perception must still be recognized as philosophical results of the highest importance. They embody the only possible answer to
