144 C L L I E E the latter supplies him with all the positive account be has to give, and that is meagre enough. The Clavis consists of two parts. After some introductory remarks, in which he explains that he will use the term " external world " in the sense of absolute, self-existent, independent matter, and fences the position he is to occupy against sundry possible misinterpretations, he attempts in the first part to prove thut the visible world is not external, by showing first, ihat the seeming externeity of a visible object is no proof of real externeity, and second, that a visible object, as such, is not external. The image of a centaur seems as much external to the mind as any object of sense ; and since the difference between imagination and perception is only one of degree, God could so act upon the mind of a person imagining a centaur, that he would perceive it as vividly as any object can be seen. Descartes and his school affirm that certain objects of sense, as sounds, smells, &c., exist only in their respective faculties, although no one can doubt that they seem to exist altogether without them. The same philosophers agree that light and colours, which are allowed to be objects properly visible, are not external. Still they seem to be so. The delusions of the insane and the visions of inspired men are further instances of seeming externality which is not real. So is the familiar case of objects seen in a looking-glass. A number of similar illustrations are used to prove the second proposition, that a visible object, as such, is not external. If we assume, for instance, that there is an external moon, it cannot be the same as the visible moon, for this is ever-changing and is never bigger than a trencher ; but the real moon is some thousands of miles in diameter. Berkeley uses the same argument in his Aldpliron (1732). Then, too, the Aristotelian and the Cartesian forms of representative perception agree in holding that the true object of vision is not the external reality. The author concludes his first part by replying to objections based on the universal con sent of men, on the assurance given by touch of the extra existence of the visible world, and on the truth and good ness of God (Descartes), which would be impugned if our senses deceived us. Collier argues naively that if universal consent means the consent of those who have considered the subject, it may be claimed for his view. He thinks with Berkeley that objects of sight are quite distinct from those of touch, and that the one therefore cannot give any assurance of the other ; and he asks the Cartesians to con sider how far God s truth and goodness are called in question by their denial of the externality of the secondary qualities. The second part of the book is taken up with a number of metaphysical arguments to prove the impos sibility of an external world. The pivot of this part is the logical principle of contradiction. From the hypothesis of an external world a series of antinomies are deduced, such as that the world is both finite and infinite, is movable and immovable, Arc.; and finally, Aristotle and various other philosophers are quoted, to show that the external matter they dealt with, as mere potentiality, is just nothing at all. Among other uses and consequences of his treatise, Collier thinks it furnishes an easy refutation of the Romish doctrine of transubstantiation. If there is no external world, the dis tinction between substance and accidents vanishes, and these become the sole essence of material objects, so that there is no room for any change whilst they remain as before. Sir William Hamilton thinks that the logically necessary advance from the old theory of representative perception to idealism was stayed by anxiety to save this miracle of the church ; and he gives Collier credit for being the first to make the discovery. 1 Professor Ueberweg, on the other hand, is of opinion that idealism and the miracle of the Hamilton s L>iscussions t pp. 198-202. eu.charist may be reconciled by regarding substance not as substrate supporting the accidents, but as intelligible essence ; so that when in the religious act the body and blood of Christ are conjoined with the bread and wine, these cease to be essential and become accidents, and a different substance is present. 2 But in that form of idealism which recognizes an intelligible essence there must be such a necessary connection between essence and phenomenon as would require the presence of new phenomena along with the new essence. Still it must have been some deeper cause than concern for the church dogma that retarded idealism. Until philosophers could be brought to reflect on the meaning of such notions as externality, cause, <tc., it was inevitable that they should continue striving to justify the belief in an external material world. Collier s blank denial would not have turned the stream. It needed a more subtle thinker to divert it into the course which it afterwards followed. Collier s took possesses an interest for the student of philo sophy on account of the resemblance between his views and those of his contemporary Berkeley. . Both were impelled to philosophize by their dissatisfaction with the theory of representative perception. Both have the feeling that it is inconsistent with the common sense of mankind, which will insist that the very object perceived is the sole reality, and both claim to substitute for the theory held in favour, and vainly sought to be demonstrated by their predecessors, another that will meet the demands of common sense. They equally affirm that the so-called representative image is the sole reality, and discard the unperceiving material cause of the philo sophers as an unthinkable monstrosity. Of objects of sense, they say, their csse is percipi. But Collier never got beyond a bald assertion of the fact, while Berkeley addressed himself to an ex planation of it, which gave him ever profounder matter for philo sophical reflection all his days. The thought of a distinction between direct and indirect perception never dawned upon Collier s mind. He could only meet the doctrine of the representationists, therefore, with a flat negation. To the question how all matter exists in dependence on percipient mind he could only reply, "Just how my reader pleases, provided it be somehow." As cause of our sensations and ground of our belief in externality, he substituted for an unintelligible material substance an equally unintelligible operation of divine power. But his illustrious contemporary gave a fresh start to philosophy by his exposition of the association between visual and tactual sensations; and his glimpses, faint at first, gradually grew more distinct of an intelligible order in the uni verse. Collier s book exhibits no traces of a scientific development. In the first part, which may be compared with Berkeley s Theory of Vision, he merely brings together a i ew instances of visual experience, which throw discredit upon the popular opinion. The most that can be said about him is that he was an intelligent student of Descartes and Malebranche, and had the ability to apply the results of his reading to the facts of his experience. He starts no original conception, contributes nothing to the development of philosopli3 r . The latter half of his book reads like the ingenious quibbling of the schoolmen. In philosophy he is a curiosity, and nothing more. His biographer tries to make out that the Clavis fell flat on the English public in comparison with the reception accorded to Berkeley s writings, on account of its inferiority in point of style. No doubt it is immensely inferior in that respect ; but the crude- ness of Collier s thought had quite as much to do with his failure to gain a hearing. Hamilton 3 allows greater sagacity to Collier than to Berkeley, for not vainly attempting to enlist men s natural belief ngainst the hypothetical realism of the philosophers. But Collier did so as far as his light enabled him. He appealed to the popular conviction that the proper object of sense is the sole reality, although he despaired of getting men to give up their belief in its externality. He moreover distinctly asserted that nothing but prejudice prevented them from doing so ; and there is little doubt that if it had ever occurred to him, as it did to Berkeley, to explain the genesis of the notion of externality, he would have been more hopeful of commend ing his theory to the popular mind. "What -Collier simply denied Berkeley tried to explain, and therein lies that real difference between the two writers which accounts for the comparative oblivion that has been the fate of the one, and justifies the place assigned to the other iii the history of philosophy. In a curious discourse on Genesis i. 1, which Collier published in 1730, under the modest title, A Specimen of a True Philosophy, we ha^e a jumble of his theological views and his philosophical opinions. Inasmuch as we are often told in Scripture that God created all 2 Annotations on Berkeley s Principles, p. 138.
3 Discussions, p. 197.