"Things contradictory are not the same,-for example, a man and not a man. But what is possible in itself and impossible in itself are contradictory, which I prove thus. What is possible in itself, and what is impossible in itself, are contradictory. But what is impossible in itself, is not possible in itself; therefore what is possible in itself, and what is impossible in itself, are contradictory; therefore they are not the same in themselves. "Quod ex se et in se includit contradictoria, differt in se ab eo quod ex se, et in se non involvit contradictoria. Sed impossibile ex se, et in se involvit contradictoria, puta homo irrationalis, quadratum rotundum, &c. Possibile vero ex se, et in se non includit contradictoria. Ergo, impossibile in se differt a possibili. "Contradictoria non sunt idem,-puta homo et non homo. Sed possibile in se, et impossibile in se sunt contradictoria, quod sic probatur. Possibile in se, et non possibile in se, sunt contradictoria. Sed impossibile in se est non possibile. Ergo, possibile in se et impossibile in se, sunt contradictoria. Ergo, in se non sunt idem."* I have already said, that the two paragraphs which I have quoted, are but a small part of the ratiocination; for, as the reasoner supposes his adversary to be very obstinate, he thinks it necessary to assail him with a multitude of arguments, even after these which he had so strenuously urged. What but the constant habit of mere verbal disputation, could have reconciled even the dullest reasoner to such reasoning as this? If we had not previously believed what is impossible, and what is possible, not to be in themselves the same, could we have believed it more, after all this labour? The only circumstance which could make us have any doubt on the subject, is the long labour of such a demonstration, in which the truth is almost hid from our view by the multitude of words. "So spins the silk-worm small, her slender store, The reign of this philosophy may now, indeed, be considered * Dirodonis Philosophiæ contractæ, Pars II. quæ est Metaphysica, Pars I. cap. i. sect. 10, 11.-The same subject is treated at much greater length, in his larger work on Metaphysics, from the 9th to the 28th page. + Pope's Works-Dunciad, B. iv. v. 253-4. merely as a thing which has been, for it is scarcely necessary to speak of one or two devoted admirers of the Aristotelean method, who may, perhaps, not yet have vanished from among us,-thrown as they are unfortunately, on too late an age, with opinions, which, in other ages, might have raised them to the most envied distinctions-who love what is very antient, and who love what is written in Greek, and who have, therefore, two irresistible reasons for venerating that philosophy, which is unquestionably much older than Newton, or Des Cartes, or Bacon, and, as unquestionably, written in a language which saves it from vulgar eyes. Or rather, to speak with more candour of such misplaced sages of other times, there may, perhaps, be some few generous, but erring lovers of wisdom, who, impressed with the real merits of Aristotle, and with the majesty of that academic sway, which he exercised for so long a period of the history of our race, give him credit for merit still greater and more extensive, than he really possessed,-but merit it must, at the same time, be acknowledged, which was long as indisputable as his real excellence, and which all the learned and honoured, of every nation, in which learning could confer honour, united in ascribing to him, and gloried in being his worshippers. The worship, however, is now past, but there are effects of the worship which still remain. We have laid aside the superstition; but, as often happens in laying aside the superstition, we have retained many of the superstitious practices. That we reason worse than we should have done, if our ancestors had reasoned better, there can be no doubt,-because we should have profited by the results of their better reasoning; but I have almost as little doubt, that we suffer from their errors, in another way, by having imbibed, as it was scarcely possible for us not to imbibe, some portion of the spirit of their Dialectic subtleties; some greater passion, for distinctions merely verbal, and for laborious demonstrations of things self-evident, than we should have felt, from the mere imperfection of our intellectual nature, if the logic of Aristotle had never been. In the division which I made of the relations suggested, by objects either perceived or conceived by us, I arranged these relations in two classes,-those of Coexistence and Succession. I have now considered, as fully as my limits will permit, the former of these classes, both as the relations occur separately, and as they occur in those series which constitute reasoning, that at each step are only progressive feelings of relation, varying as the conceptions of the relative objects are different, and connected with each other, because the conceptions that arise in the course of the reasoning, are not loose, but regular. The inquiry has led us into some of the most interesting discussions, in the Philosophy of the Mind, discussions, interesting from their own absolute importance, and, I may add, from the peculiar obscurity which has been supposed to hang over these processes of thought, though, as I flatter myself, you have seen, this obscurity does not arise so much from any peculiar difficulty in the subject, as from the labour which has been generally, or, I may say, almost universally, employed to make it difficult. For many ages, indeed, all the powers of the human understanding, seem to have had scarcely any other occupation, than that of darkening the whole scene of nature, material and intellectual,—that scene, on which the light of nature, and the light of Heaven were shining, as they shine upon it now, and in which it seemed to require all those efforts of voluntary ignorance, which the wise of those ages were so skilful and so successful in making, not to see what was before them, and on every side. You have all, perhaps, read or heard of that celebrated sage of antiquity, who is said to have put out his eyes, for no other purpose than that he might study nature better; and, if the anecdote, which there is no reason to credit, were true, it would, certainly, have been a sufficient proof of that insanity, which his fellow citizens, on another celebrated occasion, ascribed to him. What Democritus is thus said to have done, is the very folly, in which all mankind concurred, for a long succession of centuries. They put out their eyes, that they might see nature better; and they saw, as might be supposed, only the dreams of their own imagination. The order of relations which we have next to consider, are those, which, as involving the notion of time, or priority and subsequence, I have denominated Relations of Succession. On these however, it will not be necessary to dwell at any length. They require, indeed, very little more than to be simply mentioned,— the only questions of difficulty which they involve, having been discussed fully, in my Preliminary Lectures, in which it was neces sary, before proceeding to examine the changes or affections of the mind, in its varying phenomena, and the mental powers or susceptibilities which these changes or affections denote, that we should understand what is meant by the terms change and power, cause and effect. Any part of these discussions it would be quite superfluous now to repeat; since, after the full illustration of the Doctrine of Power or Efficiency, which I then submitted to you, and the frequent subsequent allusions to it, I may safely take for granted, that the doctrine itself cannot have escaped from your mem ory. The relations of succession, then, as the very name implies, are those, which the subjects of these relations bear to each other, as prior or posterior in time. What we term a cause, suggests its particular effect; what we term an effect, suggests its particular cause, when we have previously become acquainted with their order of succession. If the cause, however, suggested nothing more than the simple conception of the effect, and the effect nothing more than the simple conception of the object which was its cause, the suggestions would, of course, be referable to the power or susceptibility formerly considered by us,—that of simple suggestion, or association, as it is commonly termed. But the cause does not suggest the effect, merely as a separate object of our thought, nor the effect the cause, as a separate object. It suggests also the new feeling of their mutual relation. When I look at a picture of Titian, for example, and the conception of the painter instantly arises, I do not think of Titian merely as an individual, unconnected with the object which I perceive, I do not think of him in the same manner as I may have thought of him repeatedly, at other times, when the reading of his name, or the mention of him, in conversation on works of art, or any other accidental circumstance may have recalled him to my mind. If I had only the conception of Titian, as I may have conceived him in those other cases, the suggestion would be truly a simple suggestion; but this simple conception of the artist is instantly followed by another feeling of his connection with that particular work of his art, which is before my eyes,-a relation, which it requires no great analytic discrimination to separate from the simple conception itself, and which arises precisely in the same way as the other relations, which have been considered by us,-the relation of resemblance, for example, when in music, one air suggests to us a similar melody,-or the relation of proportion, when we think of the squares of the sides of a right angled triangle, in Pythagoras's celebrated theorem. The relations of succession, then, are as distinct from the simple perceptions or conceptions, which suggest them, and as truly indicative, therefore, of a peculiar power or susceptibility of the mind, as the relations of coexistence are distinct from the perceptions or conceptions which suggest them. They are relations either of casual or of invariable antecedence or consequence; and we distinguish these as clearly in our thought, as we distinguish any other two relations. We speak of events which happened after other events, as mere dates in chronology. We speak of other events, as the effects of events or circumstances that preceded them. The relations of invariable antecedence and consequence, in distinction from merely casual antecedence and consequence, is, as I have already frequently stated, this relation of causes and effects. When I regard any object, and feel this relation of uniform proximity of succession, which it bears to some prior object, I term it an effect of that prior object. When I look forward, instead of backward, and regard the present object, in relation to some other object, which is not yet existing, I feel a relation, which, in reference to the object that is to be produced, may be termed fitness or aptitude, and it is on our knowledge of these fitnesses or aptitudes, that all practical science is founded. By our acquaintance with this relation, we acquire a command, not merely of existing things, but almost of things, that, as yet, have scarcely any more real existence, than the creations of poetic fancy. We lead the future, almost at our will, as if it were already present. While mechanic hands are chipping the rough block, or adding slowly stone to stone, with little more foresight than of the place where the next stone is to be added, there is an eye, which has already seen that imperfect edifice in all its finished splendour, which other eyes are incapable of seeing, till year after year shall have unfolded, through a series of progressive changes, that finished form, which is their ultimate result. What is true, in architectural design, is not less true in all the other arts, which science has evolved. There are hands continually toiling to produce what exists already to the mind of that philosopher, whom they almost |