those of a seal upon wax, seems to be that which has prevailed most generally both in ancient and modern times. It occurs often in the writings of Cicero, although he does not seem to have given much faith to it. "Quid igitur? an imprimi quasi ceram animum putamus et memoriam esse signatarum rerum in mente vestigia? quæ possunt verborum, quæ rerum ipsarum esse vestigia? quæ porro tam immensa magnitudo, quæ illa tam multa possit effingere ?" The same hypothesis is alluded to by Quintilian in a passage which affords a striking instance of that philosophical good sense which is everywhere conspicuous in his writings. "Non arbitror autem mihi in hoc immorandum, quid sit quod memoriam faciat : quamquam plerique imprimi quædam vestigia nostro animo, quæ velut in ceris annulorum signa serventur, existimant." The line between those inquiries, which are confined to the laws of memory, and those speculations which profess to explain in what manner its phenomena are produced, is here strongly and distinctly drawn, and the latter rejected as altogether foreign to the business of education, or to the practical concerns of life. The ideal theory, as taught by the schoolmen, and as adopted by Locke and his followers, tended strongly to encourage philosophical students in indulging this analogical mode of conceiving the phenomena of memory. In this theory, it was assumed, as an incontrovertible principle, that in all our intellectual operations the immediate objects of our thoughts were certain images or resemblances of the things we were thinking about; and still more explicitly, if possible, was it asserted, that all our intercourse with things material (both when they are actually present to our senses, and when they are recalled to our recollection by the power of MEMORY) is carried on by the intervention of images or resemblances of the different qualities of matter. To this hypothesis, however, a variety of objections could not fail to occur to philosophers, as soon as they began to reflect with care on the operations of their own minds; and, accordingly, long before it came to be directly attacked, it seems to have been silently falling into a certain degree of discredit; metaphysical writers, during the greater part of the last century, avoiding, as much as possible, all explanations on the subject, and obviously endeavouring to keep the difficulty out of the view of their readers by the use of a more vague and indefinite phraseology than had been employed by their predecessors. Hence the introduction of the word impressions into the Philosophy of Mind; a word which (since the publication of Mr. Hume's Treatise of Human Nature) has, in a great measure, supplanted the images and ideas of Descartes and Locke. In adopting this new language, philosophers still retain that part of the ancient hypothesis which pretends to account for perception and memory by means of something distinct both from the mind and the external object; something either existing in the mind itself, or (as their language at other times implies) some impression or trace made in that part of the brain to which the mind is locally present. With respect to this term impression, it is worthy of remark, that, in its primitive sense, it denotes a stamp made on some soft substance, such as wax with a seal; in which acceptation it is plainly liable to the very same objections which apply to image or resemblance. But, since the invention of printing, it more naturally suggests to the fancy the arbitrary signs of thought which are composed of alphabetical characters; and, consequently, does not present so very 1 Tusc. Disput. I. xxv. 2 Instit. lib. xi. cap. 1. revolting an absurdity as the words to which it has succeeded. In some respects the latter theory may perhaps be regarded as a refinement on the former, analogous to that which took place in the art of writing, when conventional marks came to be substituted for the sketches or pictures employed for the same purpose in the ruder periods of society. The habitual use we make of the arts of printing and of writing in the acquisition and in the preservation of our knowledge, is apt to predispose the understanding in favour of this last theory. We conceive the memory in particular (not unnaturally, I own, upon a superficial view of the subject) to be analogous to a tablet, on which certain traces are left; by recurring to which, the mind can, as it were, read, without any fresh aids from without, the recorded results of its former experience or reflection. But although the hypothesis of impressions be not so obviously absurd as that of images, it is nevertheless, upon the whole, by far the more puerile and nugatory of the two. To say that we acquire our knowledge of the various qualities of matter by means of copies or resemblances of these qualities existing in our own minds, is at least an attempt to solve the problem about the means by which the mind carries on its intercourse with things external; whereas the substitution of impressions or arbitrary characters on the brain, instead of the images of the schoolmen, while it is equally chargeable with the other on the ground of being a gratuitous assumption, leaves the difficulty in question altogether untouched. If it is inconceivable how the sensations of which we are conscious should, by a law of our nature, suggest to us the notions of qualities to which they bear no resemblance, does it diminish the difficulty to encumber the plain statement of the fact with the additional apparatus of certain indefinite impressions on the brain, or certain vibrations in the particles of its medullary substance; for the existence of which apparatus we have no evidence whatsoever, but the assertions of philosophers. Nor is this hypothesis of impressions less nugatory, if it be supposed to have any necessary connexion with the scheme of materialism. Admitting, for a moment, the existence of these impressions, the question still recurs, what is the nature of that thinking and percipient being which reads the impressions, and avails itself of their aid in the exercise of its various faculties? Who taught the mind to interpret their import, and to annex to them notions as foreign to themselves, as alphabetical characters are to the information which they convey? Even upon this supposition, therefore, the mystery is not less astonishing than if a child, without any instructions, were to read a book the first time it was put into its hands, with a full comprehension of the author's meaning. But what I wish chiefly to insist on at present, is the obviously illogical inference which so many ingenious men seem to have been disposed to draw from the supposed impressions on the material substance of the brain, against the immateriality of that being (that thinking and percipient I) which reads and interprets these impressions. If the hypothesis which forms the foundation of this argument be true, all that follows from it is, that in the operations of perception and of memory, a process is carried on by the mind in the dark recesses of the brain, analogous to what takes place when it reads, by the intervention of the eye, the characters of a book. The question (it ought always to be remembered) is not about the nature of the thing read, but about the nature of the reader. In the case of the book, no one thinks of identifying the reader's mind with the texture of the paper, or with the chemical composition of the ink. Why then should it be imagined that any step is made towards materialism by supposing that an invisible book exists in the sensorium, by the interpretation of which we are enabled to perceive external objects; and by a reference to which we recover, as in a tablet, the knowledge which has happened to escape from the memory? If any of my readers be desirous to know what effect this innovation, in metaphysical language, had upon the theories of philosophers, he may consult a curious and now rare pamphlet, published in London in the year 1744, by J. and P. Knapton. It is entitled, "A Defence of the late Dr. Samuel Clarke, against the Reply of Sieur Lewis Philip Thummig, in favour of Mr. Leibnitz. With that reply in French and English. To which is added an original letter from Mr. Leibnitz.” This pamphlet, which is plainly the work of a well-informed, but not very profound writer, I have heard ascribed with some confidence to Dr. Gregory Sharpe, Master of the Temple. It is chiefly valuable as a specimen of the vague and fanciful metaphysical speculations which were current in England at the time of its publication. The reply in favour of Leibnitz, which gave occasion to this pamphlet, is supposed to be the work of one of his most illustrious disciples, Baron Wolf, who on this occasion assumed the fictitious name of Thummig.]* NOTE T, p. 428.-Memory. (2 8.) "Though Sir Isaac's memory was much decayed in the last years of his life, I found he perfectly understood his own writings, contrary to what I had frequently heard in discourse from many persons. This opinion of theirs might arise, perhaps, from his not being always ready at speaking on these subjects, when it might be expected he should. But as to this it may be observed, that great geniuses are frequently liable to be absent, not only in relation to common life, but with regard to some of the parts of science they are the best informed of. Inventors seem to treasure up in their minds what they have found out, after another manner than those do the same things who have not this inventive faculty. The former, when they have occasion to produce their knowledge, are in some measure obliged immediately to investigate part of what they want. For this they are not equally fit at all times; so it has often happened, that such as retain things chiefly by a very strong memory, have appeared off-hand more expert than the discoverers themselves."-Preface to Pemberton's View of Newton's Philosophy. [A remarkable illustration of this occurs in a letter from Sir Isaac himself to Mr. Oldenburg, (dated in 1676,) in which he explains the train of reasoning by which he was led to the binomial theorem. Considering the importance of the discovery, and the very early period of life at which it was made, it might have been expected that every circumstance connected with it would have made an indelible impression on his memory; yet we find, from his own words, that the fact was otherwise. "This was the way, then, in which I first entered on these speculations, which I should not have remembered, but that in turning over my papers a few weeks since, I chanced to cast my eyes on those relating to this matter."] * But L. P. Thummig was a real man and a veritable author.-Ed. NOTE U, p. 463.-Imagination. (2 5.) Going over the theory of virtue in one's thoughts, talking well, and drawing fine pictures of it; this is so far from necessarily or certainly conducing to form a habit of it in him who thus employs himself, that it may harden the mind in a contrary course, and render it gradually more insensible; i.e., form a habit of insensibility to all moral obligations. For from our very faculty of habits, passive impressions, by being repeated, grow weaker. Thoughts, by often passing through the mind, are felt less sensibly being accustomed to danger, begets intrepidity, i.e., lessens fear; to distress, lessens the passion of pity; to instances of others' mortality, lessens the sensible apprehension of our own. And from these two observations together, that practical habits are formed and strengthened by repeated acts; and that passive impressions grow weaker by being repeated upon us; it must follow, that active habits may be gradually forming and strengthening by a course of acting upon such and such motives and excitements, whilst these motives and excitements themselves are, by proportionable degrees, growing less sensible, i.e., are continually less and less sensibly felt, even as the active habits strengthen. And experience confirms this; for active principles, at the very time they are less lively in perception than they were, are found to be somehow wrought more thoroughly into the temper and character, and become more effectual in influencing our practice. The three things just mentioned may afford instances of it. Perception of danger is a natural excitement of passive fear and active caution; and by being inured to danger, habits of the latter are gradually wrought at the same time that the former gradually lessens. Perception of distress in others, is a natural excitement passively to pity, and actively to relieve it; but let a man set himself to attend to, inquire out, and relieve distressed persons, and he cannot but grow less and less sensibly affected with the various miseries of life with which he must become acquainted; when yet, at the same time, benevolence, considered not as a passion, but as a practical principle of action, will strengthen; and whilst he passively compassionates the distressed less, he will acquire a greater aptitude actively to assist and befriend them. So also, at the same time that the daily instances of men's dying around us, give us daily a less sensible passive feeling or apprehension of our own mortality, such instances greatly contribute to the strengthening a practical regard to it in serious men; i.e., to forming a habit of acting with a constant view to it."-Butler's Analogy, p. 122, 3d edit. ADDENDA. NOTES. P. 293, to the end of the second paragraph-" one and the same.' * The following annotation, in Mr. Stewart's hand-writing, was found in the third edition (1808) of the first volume of the Elements, extant among his books in the Library of the United Service Club, London. With other annotations, it was politely extracted by Mr. B. K. Wheatley.-Ed. [The foregoing account of the state of the mind in sleep, agrees exactly with the following description of Virgil, (Eneid, xii. 908.) Ac velut in somnis oculos ubi languida pressit Dryden's Translation :- "And as when heavy sleep has closed the sight, P. 496, to the end of Note 1.*. * I ought not to omit a reference to Mr. Stewart's correction of this note in the Dissertation, (Works, vol. i. p. 583,) where he says:-" By a strange slip of memory, I ascribed the merit of this very judicious qualification, not to Addison, but to Dr. Akenside, who transcribed it from the Spectator.”—Ed. P. 497. 1. 22.—“ Appartenir."* * The substance of this passage, (which appears to be from some article in the Encyclopédie, not contained in the Mélanges,) is to be found in sect. vi. of the Elémens de Philosophie, entitled Métaphysique; (Mélanges, tome iv. pp. 60, 61); but it is not there articulately given. A partial translation by Mr. Stewart occurs in the Dissertation, p. 129.-Ed. VOL. II. EDINBURGH T. CONSTABLE, PRINTER TO HER MAJESTY. 2 K |