276 Sense, which Dr. Reid published in 1764. As this work developed an argument against the sceptical philosophy of Mr. Hume, the author, with more magnanimity than some members of his profession displayed at the time, procured, by the interposition of Dr. Blair, a perusal of the manuscript by Hume, in order that any of those disputes from mere mis- understanding of words, so pernicious to philoso- phical discussion, might be avoided. Hume at first displayed some disinclination, founded on previous experience of others, to encourage this new assailant. "I wish," he said, "that the parsons would confine themselves to their old occupation of worrying one another, and leave philosophers to argue with tem- per, moderation, and good manners." But his liberal mind did not permit him, on seeing the manuscript, and knowing the worth of its author, to yield to his hasty anticipations. Writing personally to Reid he said, "By Dr. Blair's means I have been favoured with the perusal of your performance, which I have read with great pleasure and attention. It is cer- tainly very rare that a piece so deeply philosophical is wrote with so much spirit, and affords so much entertainment to the reader, though I must still regret the disadvantages under which I read it, as I never had the whole performance at once before me, and could not be able fully to compare one part with another. To this reason chiefly I attribute some obscurities which, in spite of your short analysis or abstract, still seem to hang over your system. For I must do you the justice to own that, when I enter into your ideas, no man appears to express himself with greater perspicuity than you do; a talent which, above all others, is requisite in that species of literature which you have cultivated. There are some objections which I would willingly propose to the chapter "Of Sight," did I not suspect that they proceed from my not sufficiently understanding it; and I am the more confirmed in this suspicion, as Dr. Black tells me that the former objections I had made had been derived chiefly from that cause. I shall therefore forbear till the whole can be before me, and shall not at present propose any farther difficulties to your reasonings. I shall only say, that if you have been able to clear up these abstruse and important subjects, instead of being mortified, I shall be so vain as to pretend to a share of the praise; and shall think that my errors, by having at least some coherence, had led you to make a more strict review of my principles, which were the common ones, and to perceive their futility." It may be as well here to pass over the interven- ing events of Dr. Reid's life, and give a brief sketch of the principles of his philosophy, as developed in his other works, to which, as Mr. Stewart has pro- perly remarked, the Inquiry into the Human Mind forms an introduction. In 1785 he published his Essays on the Intellectual Powers of Man, and in 1788 those on the Active Powers. These two have been generally republished together, under the well- known title, Essays on the Powers of the Human Mind; a work which has gradually gained ground in the estimation of intelligent thinkers, and is now used as a text-book by many eminent teachers of philosophy. When it is said that Dr. Reid's philo- sophy is entirely, or intended to be entirely, syn- thetical, and that it adopts no theory, except as an induction from experiment, it will readily be under- stood that a view of its general principles and ten- dency cannot be given; but it is not on this account very difficult to describe the method by which he reasoned, and came to the different conclusions he has adopted. Reid has generally received, and probably with justice, the praise of having been the first to extend, by a general system, the process of reasoning from experiment, so strongly recommended by Bacon in natural science, to the operations of the mind. In this he was, to a certain extent, anticipated by Hume, who, especially in his arguments on cause and effect, and his essay on miracles, proceeded on analyses of our experience: but the two philosophers followed a different method; the sceptic using his experience to show the futility of any systems of philosophy which had been raised; while Reid made use of them to redeem, as it were, mental science, by eschewing these systems, and founding one of his own on that experience which he saw had enabled the sceptic to demolish the systems destitute of such a support. But to accomplish his purpose—and this is what distin- guishes his philosophy from all other systems—Reid found it necessary to set bounds to his inquiries, which other philosophers had passed. He abstained from that speculation concerning the nature and essence of the mind itself, which, as followed by others, had formed the most convenient object of demolition to the sceptic, and limited himself to observations on the operations of the mind, as he saw them performed before him. Instead, therefore, of appealing to any theories of his own (which he knew would require to be founded on vague speculation, and independently of observation) on the essence of the mind, when he tried the truth of his observations he appealed to what he called " common sense," or that sense, however acquired, which prompts us to believe one thing and disbelieve another. Hence it might be said, in common language, that instead of making his inquiries by means of subtle and metaphysical reasonings, he stated his views, trusting that his readers would believe him from their common sense, and if they did not choose to do so, knowing that the greater part of the world was on his side, despite of any fine-spun objections which might be produced by the sophist. The following, perhaps, more than most other passages in his works, bears a marked stamp of his method of reasoning: "Perhaps Des Cartes meant not to assume his own existence in this enthymeme, but the existence of thought, and to infer from that the existence of a mind or subject of thought. But why did he not prove the existence of his thought? Consciousness, it may be said, vouches that. But who is voucher of the conscious- ness? Can any man prove that his consciousness, may not deceive him? No man can: nor can we give a better reason for trusting to it, than that every man, while his mind is sound, is determined, by the constitution of his nature, to give implicit belief to it, and to laugh at, or to pity, the man who doubts its testimony. And is not every man in his wits as determined to take his existence upon trust as his consciousness?"1 It is easier to find objections to, than to erect a system of metaphysical philosophy; and that of Reid affords ample room for controversy. Admitting that the only ground on which we can ever place metaphysical truths is, the general belief of men of sound mind, it must still, in every instance, be a very questionable matter, whether these men of sound mind have come to the right conclusion, and whether it may not be possible, by a little more in- vestigation and argument, even though conducted by a sceptical philosopher, to show reasons for coming to a different conclusion, and to establish it upon the very same grounds, viz. the general belief of men of sound mind. When Galileo discovered that nature abhorred a vacuum, and was afterwards obliged to admit that this abhorrence did not extend above 1 Inquiry (1819), 28.