represents it to be an extended substance, without any other quality, and embracing space as a part of itself. Now, if such an idea appertained naturally to him, it must, in like manner, appertain naturally to every one. Let me, then, ask the audience I have the honour of addressing, whether the same notion has ever presented itself, as it necessarily ought to have done, to the minds of every one or of any one before me? and whether they seriously believe that SPACE is a part of MATTER? So far from it, that I much question whether even the meaning of the position is universally understood; while. with respect to those by whom it is understood, I have a shrewd suspicion it is not assented to; and that they would even apprehend some trick had been played upon them if they should find it in their minds. The good father Malebranche, as excellent a Cartesian as ever lived, and who possessed withal quite mysticism enough to have succeeded Plato, upon his death, and turned Xenocrates out of the chair, suspected that tricks like these are perpetually played upon us. For he openly tells us, in his Recherche de la Vérité, that ever since the fall, Satan has been making such sad work with our senses, both external and internal, that we can only rectify ourselves by a vigorous determination to doubt of every thing, after the tried and approved Cartesian recipe: and if a man, says he, has only learned to doubt, let him not imagine that he has inade an inconsiderable progress. And for this purpose, he recommends retirement from the world, a solitary cell, and a long course of penitence and water-gruel: after which our innate ideas, he tells us, will rise up before us at a glance: our senses, which were at first as honest faculties as one could desire to be acquainted with, till debauched in their adventure with original sin, will no longer be able to cheat us, we shall see into the whole process of transubstantiation, and though we behold nothing in matter, we shall behold all things in God. It may, perhaps, be conceived that I treat the subject before us somewhat too flippantly or too cavalierly. It is not, however, the subject before us that I thus treat, but the hypothesis; and, in truth, it is the only mode in which I feel myself able to treat it at all; for I could as soon be serious over the "Loves of the Plants," or "The Battle of the Frogs." And I must here venture to extend the remark a little farther, and to add, that there is but one hypothesis amid all those that yet remain to be examined, that I shall be able to treat in any other manner; for, excepting in this one, there is not a whit of superiority that I can discover in any of them; and the one I refer to, though I admit its imperfections in various points, is that of our own enlightened countryman, Mr. Locke. I may, perhaps, be laughed at in my turn, and certainly should be so if I were as far over the Tweed as over the Thames, and be told that I am at least half a century behind the times. Yet, by your permission, I shall dare the laugh, and endeavour, at least, to put merriment against merriment; and shall leave it to yourselves to determine, after a full and impartial hearing, who has the best claim to be pleasant. So that the study of metaphysics may not, perhaps, appear quite so gloomy and repugnant as the writings of some philosophers would represent it. If it have its gravity, it may also be found to have its gayety as well; and to prove that there is no science in which it better becomes us to adopt the maxim of the poet, and to Laugh where we may, be serious where we can, But vindicate the ways of God to man. LECTURE IV. ON HUMAN UNDERSTANDING. (The Subject continued.) In our preceding study we commenced a general survey of the chief opinions and hypotheses that have been urged in different periods upon the important subject of Human Understanding; and, opening our career with the Greek schools, we closed it with that of Des Cartes. Des Cartes, who was born in 1596, was for nearly a century, the Aristotle of his age; and, although from his very outset he was opposed by his contemporaries and literary friends Gassendi and Hobbes, he obtained a complete triumph, and steadily supported his ascendant, till the physical philosophy of Newton, and the metaphysical of Locke, threw an eclipse over his glory, from which he has now no chance of ever recovering. Nothing, however, can prove more effectually the influence which fashion operates upon philosophy as well as upon dress, than a glance at the very opposite characters by whom the Cartesian system was at one and the same time principally professed and defended-Malebranche and Spinosa, Leibnitz and Bayle. It would, perhaps, be impossible, were we to range through the whole scope of philosophical or even of literary biography, to collect a more motley and heterogeneous group: the four elements of hot, cold, moist, and dry cannot possibly present a stronger contrast; a mystical Catholic, a Jewish materialist, a speculative but steady Lutheran, and a universal skeptic. It was only, however, for want of a simpler and more rational system, that Des Cartes continued so long and so extensively to govern the metaphysical taste of the day. That system was at length given to the world by Mr. Locke, and the "PRINCIPIA PHILOSOPHIE" fell prostrate before the "ESSAY CONCERNING HUMAN UNDERSTANDING." This imperishable work made its first appearance in 1689: it may, perhaps, be somewhat too long; it may occasionally embrace subjects which are not necessarily connected with it: its terms may not always be precise, nor its opinions in every instance correct; but it discovers intrinsic and most convincing evidence that the man who wrote it must have had a head peculiarly clear, and a heart peculiarly sound. It is strictly original in its matter, highly important in its subject, luminous and forcible in its argument, perspicuous in its style, and comprehensive in its scope. It steers equally clear of all former systems: we have nothing of the mystical archetypes of Plato, the incorporeal phantoms of Aristotle, or the material species of Epicurus; we are equally without the intelligible world of the Greek schools, and the innate ideas of Des Cartes. Passing by all which, from actual experience and observation it delineates the features and describes the operations of the human mind, with a degree of precision and minuteness which have never been exhibited either before or since.* "Nothing," says Dr. Beattie, and I readily avail myself of the acknowledgment of an honest and enlightened antagonist, was farther from the intention of Locke than to encourage verbal controversy, or advance doctrines favourable to skepticism. To do good to mankind by enforcing virtue, illustrating truth, and vindicating liberty, was his sincere purpose. His writings are to be reckoned among the few books that have been productive of real utility to mankind."+ 66 To take this work as a text-book, of which, however, it is well worthy, would require a long life instead of a short lecture: and I shall, hence, beg leave to submit to you only a very brief summary of the more important part of its system and of the more prominent opinions it inculcates, especially in Study of Med. vol. 1. p. 49, 2d edit. † Essay on Truth, part 11. ch. ii. § 2. respect to the powers and process of the mind in acquiring knowledge. The work consists of four divisions, the first of which, however, is merely introductory, and intended to clear the ground of that multitude of strong and deep-rooted weeds at which we have already glanced, and which, under the scholastic name of præcognita, innate ideas, maxims, and dictates, or innate speculative and practical principles, prevented the growth of a better harvest; and, to a certain extent, superseded the necessity of reason, education, and revelation, of national institutions and Bible societies; by teaching that a true and correct notion of God, of self or consciousness, of virtue and vice, and, consequently, of religious and moral duties, is imprinted by nature on the mind of every man; and that we cannot transgress the law thus originally implanted within us without exposing ourselves to the lash of our own consciences. Discarding for ever all this jargon of the schools, the Essay before us proceeds in its three remaining parts to treat of IDEAS, which, in the popular, and not the scholastic, sense of the term, are the elements of knowledge; of WORDS, which are the signs of ideas, and consequently the circulating medium of knowledge; and of KNOWLEDGE itself, which is the subject proposed, and the great end to be acquired. The whole of the preceding rubbish, then, being in this manner cleared away, the elaborate author proceeds to represent to us the body and mind as equally at birth a tabula rasa, or unwritten sheet of paper: as consisting equally of a blank or vacuity of impressions, but as equally capable of acquiring impressions by the operation of external objects, and equally and most skilfully endowed with distinct powers or faculties for this purpose; those of the body being the external senses of sight, hearing, smell, taste, and touch; and those of the mind the internal senses of perception, reason, judgment, imagination, and memory.* It is possible that a few slight impressions may be produced a short time antecedently to birth; and it is certain that various instinctive tendencies, which, however, have no connexion with the mind, are more perfect, because more needful, at the period of birth than ever afterward; and we have also frequent proofs of an hereditary or accidental predisposition towards particular subjects. But the fundamental doctrine before us is by no means affected by such collateral circumstances; to the correctness of which our most eminent logicians of later times have given their entire suffrage. Thus Bishop Butler, and it is not necessary to go farther than this eminent casuist: -“In these respects," meaning those before us, "mankind is left by nature an unformed, unfinished creature, utterly deficient and unqualified, before the acquirement of knowledge, experience, and habits, for that mature state of life which was the end of his creation, considering him as related only to this world. The faculty of reason is the candle of the Lord within us; though it can afford no light where it does not shine, nor judge where it has no principles to judge upon."t External objects first impress or operate upon the outward senses, and these senses, by means hitherto unexplained, and, perhaps, altogether inexplicable, immediately impress or operate upon the mind, or excite in it perceptions or ideas of the presence and qualities of such objects; the word idea being employed in the system before us, not, as we have already hinted at, in any of the significations of the schools, but in its broad and popular meaning, as importing "whatever a man observes and is conscious to himself he has in his mind;"‡ whatever was formerly intended by the terms archetype, phantasm, species, thought, notion, conception, or whatever else it may be, which we can be employed about in thinking. And to these effects, without puzzling himself with the inquiry how external objects operate upon the senses, or the senses upon the mind, Mr. Locke gave the name of ideas of SENSATION, in allusion to the source from which they are derived. * An abstract of this view of Mr. Locke's system, abbreviated for the occasion, the author found himself called upon to introduce into his Study of Medicine. Vol. iv. p. 50-55, 2d edit. 1825. † Analogy of Religion, Natural and Revealed, part 1. ch. v. part 11. Conclusion. Locke, book i.ch. i. 03. Ib. $8. But the mind, as we have already observed, has various powers or faculties as well as the body; and they are quite as active and lively in their respective functions. In consequence of which the ideas of external objects are not only perceived, but retained, thought of, compared, compounded, abstracted, doubted, believed, desired; and hence another fountain, and of a very capacious flow, from which we also derive ideas, namely, a reflex act or perception of the mind's own operations; whence the ideas derived from this fountain are denominated ideas of REFLECTION. The ideas, then, derived from these two sources, and which have sometimes been called OBJECTIVE, and SUBJECTIVE,* constitute all our experience, and consequently all our knowledge. Whatever stock of information a man may be possessed of, however richly he may be stored with taste, learning, or science, if he turn his attention inwards, and diligently examine his own thoughts, he will find that he has not a single idea in his mind but what has been derived from the one or the other of these two channels. But let not this important observation be forgotten by any one; that the ideas the mind possesses will be fewer or more numerous, simpler or more diversified, clear or confused, according to the number of the objects or subjects presented to it, and the extent of its reflection and examination. Thus, a clock or a landscape may be for ever before our eyes, but unless we direct our attention to them, and study their different parts, although we cannot be deceived in their being a clock or a landscape, we can have but a very confused idea of their character and composition. The ideas presented to the mind, from which of these two sources soever derived, or, in other words, whether objective or subjective, are of two kinds, SIMPLE and complex. SIMPLE IDEAS Consist of such as are limited to a single notion or perception; as those of unity, darkness, light, sound, hardness, sweetness, simple pain, or uneasiness. And in the reception of these the mind is passive, for it can neither make them to itself, nor can it, in any instance, have any idea which does not wholly consist of them; or, in other words, it cannot contemplate any one of them otherwise than in its totality. Thus, on looking at this single sheet of paper, I have the idea of unity; and though I may divide the single sheet of paper into twenty parts, I cannot divide the idea of unity into twenty parts; for the idea of unity will and must as wholly accompany every part as it accompanies the collective sheet. And the same remark will apply to all the rest. COMPLEX IDEAS are formed out of various simple ideas associated together, or contemplated derivatively. And to this class belong the ideas of an army, a battle, a triangle, gratitude, veneration, gold, silver, an apple, an orange: in the formation of all which it must be obvious that the mind is active, for it is the activity of the mind alone that produces the complexity out of such ideas as are simple. And that the ideas I have now referred to are complex, must be plain to every one; for every one must be sensible that the mind cannot form to itself the idea of an orange without uniting into one aggregate the simple ideas of roundness, yellowness, juiciness, and sweetness. In like manner, in contemplating the idea of gold, there must necessarily be present to the mind, and in a complex or aggregate form, the ideas of great weight, solidity, yellowness, lustre: and if the idea be very accurate, great malleability and fusibility. Complex ideas are formed out of simple ideas by many operations of the mind; the principal of which, however, are some combination of them, some abstraction, or some comparison. Let us take a view of each of these: *"On appelle, dans la philosophie Allemande, idées subjectives celles que naissent de la nature de notre ntelligence et de ses facultés, et idées objectives toutes celles que sont excitées par les sensations."-Mad. e Staël Holstein, de l'Allemagne, tom. iii. p. 76. Mad. de Staël, however, has fallen into the common error of the French philosophers, from whom she appears to have generally informed herself of the principles of Locke's system, in supposing that he derived all ideas from sensation. "A l'époque où parut la Critique de la Raison pure, il n'existoit que deux systêmes sur l'entendement humain parmi les penseurs; l'une, celui de Locke, attribuoit toutes nos idées à nos sensations; l'autre, celui de Des Cartes et de Leibnitz, s'attachoit a démontrer la spiritualité et l'acti vité de l'âme, de libre arbitre, enfin toute la doctrine idéaliste."-lb. p. 70. Z And, first, of complex ideas of COMBINATION. Unity, as I have already observed, is a simple idea: and it is one of the most common simple ideas that can be presented to the mind, for every object without, and every idea within, tend equally to excite it. And, as being a simple idea, the mind, as I have also remarked, is passive on its presentation; it can neither form such an idea to itself, nor contemplate it otherwise than in its totality: but it can combine the ideas of as many units as it pleases, and hence produce the complex idea of a hundred, a thousand, or a hundred thousand. So beauty is a complex idea; for the mind, in forming it, combines a variety of separate ideas into one common aggregate. Thus Dryden, in delineating the beautiful Victoria, in his "Love Triumphant :" Her eyes, her lips, her cheeks, her shape, her features, In like manner the mind can produce complex ideas by an opposite process, and that is, by ABSTRACTION, or separation. Thus chalk, snow, and milk, though agreeing, perhaps, in no other respect, coincide in the same colour; and the mind, contemplating this agreement, may abstract or separate it from the other properties of these three objects, and form the idea which is indicated by the term whiteness; and having thus acquired a new idea by the process of abstraction, it may afterward apply it as a character to a variety of other objects: and hence particular ideas become general or universal. Other complex ideas are produced by COMPARISON. Thus, if the mind take one idea, as that of a foot, as a determinate measure, and place it by the side of another idea, as the idea of a table, the result will be a formation of the complex idea of length, breadth, and thickness. Or if we vary the primary ideas, we may obtain as a result the secondary ideas of coarseness and fineness. And hence, complex ideas must be almost infinitely more numerous than simple ideas, which are their elements or materials, as words must be always far more numerous than letters. I have instanced only a few of their principal kinds; but even each of these kinds is applicable to a variety of subjects, of which Mr. Locke mentions the three following: I. IDEAS OF SUBSTANCES; or such as we have uniformly found connected in the same thing, and without which, therefore, such thing cannot be contemplated. To this head belong the complex ideas of a man, a horse, a river, a mountain. 11. IDEAS OF MODES; or such as may be considered as representative of the inere affections, or properties of substance; of which the idea of number may once more be offered as an example: the ideas of expansion or extension and duration belong to the same stock; and in like manner those of power, time, space, and infinity, which are all modes, properties, or affections of substance; or secondary ideas derived from or excited by the primary idea of substance of some kind or other. III. IDEAS OF RELATIONS; which are by far the most extensive, if not the most important, branch of subjects from which our complex ideas are derived; for there is nothing whatever, whether simple idea, substance, mode, relation, or even the name of any of them, which is not capable of an almost infinite number of bearings in reference or relation to other things. It is from this source, therefore, that we derive a very large proportion of our thoughts and words. As examples under it, I may mention all those ideas that relate to or are even imported by the terms father, brother, son, master, magistrate, younger, older, cause and effect, right and wrong, and, consequently, all moral relations. It must hence appear obvious that many of our ideas have a NATURAL CORRESPONDENCE, Congruity, and connexion with each other. And as many, perhaps, on the contrary, a NATURAl repugnancy, incongruity, and disconnexion. Thus if I were to speak of a cold fire, I should put together ideas that are naturally disconnected and incongruous, and should consequently make an absurd proposition, or, to adopt common language, talk nonsense. I should |