Lectures on the Philosophy of the Human Mind (Vol. 1 of 3)

Such is one of the answers which may be given to the question; and this sort of answer is one which is very commonly given to such questions. It is, you will perceive, nothing more than the enumeration of the constituent parts of the substance, and considers the substance, simply as it exists alone, without regard to any other bodies that may exist around it, or near it, and without any allusion to change of any kind.

This sort of view, however, may be altogether reversed; and, instead of thinking of the parts that exist together in the substance, without reference to any changes, of which it is either the agent or the subject, we may think only of such changes, without reference to its constituent parts.

In this latter point of view, we may say, in answer to the question, as to the nature of the substance termed glass, that it is a transparent substance, which, according to the general laws of refraction, bends the light that passes through it variously, according to the different density of the medium through which the rays have immediately passed before arriving at it, or of the medium, through which they are to pass after penetrating it; that it is a substance fusible at a certain temperature, not dissolved by the common powerful acids, but soluble in a particular acid termed the fluoric acid; that, when strongly rubbed, by certain other substances, it communicates, for a time, to various bodies, the power of attracting or repelling other bodies; and we may add to our description, in like manner, as many other qualities as there are various substances which produce in it any change, or are in any way changed by it. In all answers of this kind, you will perceive that regard is uniformly had, not to the mere substance, concerning which the question is put, but also to some other substance with which, in consequence of some motion of one or other of the bodies, at the time of the phenomenon of which we speak, it has changed its relative position; for, if all the objects in nature remained constantly at rest, it is very evident that we could have no notion of any property of matter whatever. In the enumeration of the qualities of glass, for example, when we speak of its properties, we suppose it to have changed, in every case, some relative position with the light that passes through it, the heat that melts it, the fluoric acid that dissolves it, and the various bodies that excite in it, or conduct from it, electricity; and all these bodies, therefore, we must have in view, in our enumeration, as much as the glass itself.

As there are only these two different aspects in which matter can be viewed, all physical inquiry, with respect to matter, must, as I have said, have reference to one of them; and if we think that we are inquiring further concerning it, our inquiry is truly without an object, and we know not what we seek. We may consider it, simply as it exists in space, or as it exists in time. Any substance, considered as it exists in space, is the mere name which ourselves give to the co-existence of a multitude of bodies, similar in nature, or dissimilar, in apparent continuity; considered as it exists in time, it is that which is affected by the prior changes of other bodies, or which itself produces a change of some sort in other bodies. As it exists in space, therefore, we inquire into its composition, or, in other words, endeavour to discover what are the elementary bodies that co-exist in the space which it occupies, and that are all which we truly consider, when we think that we are considering the compound as one distinct body. As it exists in time, we inquire into its susceptibilities or its powers, or, in other words, endeavour to trace all the series of prior and subsequent changes, of which its presence forms an intermediate link.

This, then, is our meaning, when we speak of inquiring into the nature of a substance. We have one, or both of two objects in view, the discovery of the separate bodies that co-exist in the substance, or rather that constitute the substance, which is nothing more than the separate bodies themselves, or the discovery of that series of changes, of which the presence of this particular substance, in some new relative position with respect to other bodies, forms a part; the changes which other bodies, in consequence of this altered relative position, occasion in it, with the changes which it occasions in other bodies.

On these two different objects of physical investigation, the co-existing elements of bodies, and their successions of changes, it may be of advantage to dwell a little more fully in elucidation of the method which we have to pursue in our own department of physical research; for, though it may perhaps at first appear to you, that to treat of the principles of inquiry, in the physics of matter, is to wander from the intellectual and moral speculations which peculiarly concern us; it is in truth only as they are illustrative of inquiries which we are to pursue in the physiology of the mind, that I am led to make these general remarks. The principles of philosophic investigation are, as I have already said, common to all the sciences. By acquiring more precise notions of the objects of any one of them, we can scarcely fail to acquire, in some degree, more precision in our notions of every other, and each science may thus be said to profit indirectly by every additional light that is thrown upon each. It is by this diffusive tendency of its spirit, almost as much as by its own sublime truths, and the important applications of these to general physics, that the study of geometry has been of such inestimable advantage to science. Those precise definitions which insure to every word the same exact signification, in the mind of every one who hears it pronounced, and that lucid progress in the developement of truth after truth, which gives, even to ordinary powers, almost the same facility of comprehension with the highest genius, are unquestionably of the utmost benefit to the mathematical student, while he is prosecuting his particular study, without any contemplation of other advantages to be reaped from them. But there can be no doubt that they are, at the same time, preparing his mind for excellence in other inquiries, of which he has then no conception; that he will ever after be less ready to employ, and be more quicksighted than he would otherwise have been in detecting vague and indefinite phraseology, and loose and incoherent reasoning; and that a general spirit of exactness and perspicuity may thus at length be diffused in society, which will extend its influence, not to the sciences merely, but, in some faint degree, also to works of elegant literature, and even to the still lighter graces of conversation itself. “The spirit of geometrical inquiry,” says Fontenelle, “is not so exclusively attached to geometry, as to be incapable of being applied to other branches of knowledge. A work of morals, of politics, of criticism, or even of eloquence, will, if all other circumstances have been the same, be the more beautiful, for having come from the hand of a geometrician. The order, the clearness, the precision, which, for a considerable time, have distinguished works of excellence on every subject, have most probably had their origin in that mathematical turn of thought, which is now more prevalent than ever, and which gradually communicates itself even to those who are ignorant of mathematics. It often happens that a single great man gives the tone to the whole age in which he lives; and we must not forget, that the individual who has the most legitimate claim to the glory of having introduced and established a new art of reasoning, was an excellent geometer.”[22 - Preface aux Eloges – Œuvres, tom. v. p. 8.] The philosopher to whom this improvement of the art of reasoning is ascribed, is evidently Descartes, whose claim is certainly much less legitimate than that of our own illustrious countryman; but the works of Bacon were not very extensively studied on the continent, at the time at which Fontenelle wrote; while especially in France, the splendid reputation of the great geometer, who shook, as much with his own wild hypothesis, as with the weight of his reasoning, the almost idolatrous worship of the God of the Schools, seemed to sweep before it the glory of every other reformer. The instance of Descartes, however, is a still more happy one than his ingenious countryman, who was himself a Cartesian, could have imagined it to be. It is, indeed, impossible to conceive a more striking example of that diffusive influence of the general spirit of scientific inquiry, which I wish to illustrate; since, in this instance, it survived the very system by which it was diffused; all that was sceptical in that mixed system of scepticism and dogmatism which constituted the philosophy of Descartes, having long continued, and even now continuing, to operate beneficially, when scarcely a doctrine of his particular philosophy retains its hold.

You will not then, I trust, take for granted, that precise notions as to the objects of inquiry, in any science, even in the department of external physics, can be so absolutely without benefit to our plans of inquiry into mind, which must be pursued on the same principles, if it be pursued with any prospect of success; and I may, therefore, safely solicit your attention to a little farther elucidation of the two objects which we have in view, in general physical inquiry, whether it be relative to matter or to mind.

To inquire into the composition of a substance, is to consider as one, many substances, which have not the less an independent existence, because they are in immediate proximity to each other. What we term a body, however minute, is a multitude of bodies, or to speak more exactly, an infinite number of bodies, which appear limited to us, indeed, but may perhaps appear, in their true character of infinity, to beings of a higher order, who may be able to distinguish as infinite, what our limited senses allow us to perceive only as finite. They are one, not in nature, but in our thought; as one thousand individuals, that in nature must always be one thousand, receive a sort of unity that is relative merely to our conception, when ranked by us as a single regiment, or as many regiments become one by forming together an army. In the energies of external matter, the innumerable separate bodies are thus regarded by us as one, when the space which divides them is not measurable by our imperfect vision, and as distinct or separate, when the space can be measured by us. The unity of the aggregate is here no absolute quality of the mass, but is truly relative to the observer's power of distinguishing the component parts; the mass being one or many, as his senses are less or better able to distinguish these. This whole globe of earth, with its oceans, and rivers, and mountains, and woods, and with all the separate multitudes of its animated inhabitants, may seem to some being of another species, only one continuous and uniform mass; as the masses, that seem to us uniform and continuous, may seem a whole world of separate and varied parts, to the insect population that swarms upon its surface. “A single leaf of a tree,” to borrow an obvious illustration from a French writer, “is a little world inhabited by invisible animals, to whose senses it appears of immense extent, who see in it mountains and abysses that are almost immeasurable, and who, from one side of the leaf to the other, hold as little communication with the opposite animalcula, who have their dwellings there, as we do with our Antipodes.”[23 - Fontenelle, Pluralité des Mondes, Conversat. 3.]

Nothing can appear to our eyes more uniform than a piece of glass; yet we know, from its composition, as a product of art, that it is a congeries of bodies, which have no similarity to each other, and which truly exist separately from each other, in the compound, as they existed separately before the composition, though the lines of space which divide them have now ceased to be visible to our weak organs; and though, instead of being composed of alkaline and siliceous matter, which we know to be different in their qualities, the beautiful transparent substance, considered by us, were, as far as we know, simple, in the chemical sense of the term, it would still be as truly an aggregate of many bodies, not dissimilar, indeed, as in the former case, but each similar in qualities to the aggregate itself. The aggregate, in short, is, in every case, but a name invented by ourselves; and what we term the constituent elements, are all that truly exists. To inquire into the composition of a body, is, therefore, only to inquire what these separate bodies are which we have chosen to consider as one, or rather which are ranked by us as one, from their apparent continuity.

I have dwelt the longer on this point of the unity of an aggregate mass, as derived from the mind of the observer only, and not from its constituent bodies, which are truly separate and independent of each other, and must always be separate and independent, whatever changes they may seem to undergo, in the various processes of composition and decomposition, because this is one of the most simple, and, at the same time, one of the most convincing examples of a tendency of the mind, which we shall often have occasion to remark in the course of our intellectual analysis, – the tendency to ascribe to substances without, as if existing in them like permanent physical qualities, the relations which ourselves have formed, by the mere comparison of objects with objects, and which, in themselves, as relations, are nothing more than modifications of our own mind. It is very difficult for us to believe, that, when we speak of a rock, or a mountain, or, perhaps, still more, when we speak of a single leaf or blade of grass as one, we speak of a plurality of independent substances, which may exist apart, as they now exist together, and which have no other unity than in our conception. It is the same with every other species of relation. The tallness of a tree, the lowness of a shrub or weed, as these relative terms are used by us in opposition, do not express any real quality of the tree, or shrub, or weed, but only the fact that our mind has considered them together; all which they express, is the mere comparison that is in us, not any quality in the external objects; and yet we can scarcely bring ourselves to think, but that independently of this comparison, there is some quality, in the tree, which corresponds with our notion of tallness, and some opposite quality in the shrub or weed, which corresponds with our notion of shortness or lowness; so that the tree would deserve the name of tall, though it were the only object in existence, and the shrub or weed, in like manner, the epithet of lowly, though it alone existed, without a single object with which it could be compared. These instances, as I have said, are simple, but they will not be the less useful, in preparing your minds for considering the more important natures of relation in general, that imply, indeed, always some actual qualities in the objects themselves, the perception of which leads us afterwards to consider them as related, but no actual quality in either of the objects that primarily and directly corresponds with the notion of the relation itself, as there are qualities of objects that correspond directly with our sensations of warmth or colour, or any other of the sensations excited immediately by external things. The relation is, in every sense of the word mental, not merely as being a feeling of the mind, for our knowledge of the qualities of external things is, in this sense, equally mental; but, as having its cause and origin directly in the very nature of the mind itself, which cannot regard a number of objects, without forming some comparison, and investing them consequently with a number of relations. I have already spoken of the intellectual medium, through which external objects become known to us; and the metaphor is a just one. The medium, in this case, as truly as in the transmission of light, communicates something of its own to that which it conveys; and it is as impossible for us to perceive objects long or often together, without that comparison which instantly invests them with certain relations, as it would be for us to perceive objects, for a single moment, free from the tint of the coloured glass through which we view them. “Omnes perceptiones,” says Lord Bacon, using a similar figure, “omnes perceptiones, tam sensus quam mentis, sunt ex analogia hominis, non ex analogia universi; estque intellectus humanus instar speculi inæqualis ad radios rerum, qui suam naturam naturæ rerum immiscet, eamque distorquet et inficit.”

But, whatever may be thought of relations in general, there can be no question, at least, as to the nature of that unity which we ascribe to bodies. We have seen, that the substance, which, in thought we regard as one, is, in truth, not one, but many substances, to which our thought alone gives unity; and that all inquiry, therefore, with respect to the nature of a substance, as it exists in space, is an inquiry into the nature of those separate bodies, that occupy the space which we assign to the imaginary aggregate.

To dissipate this imaginary aggregate of our own creation, and to show us those separate bodies which occupy its space, and are all that nature created, is the great office of the analytic art of Chemistry, which does for us only what the microscope does, that enables us to see the small objects which are before us at all times, without our being able to distinguish them. When a chemist tells us, that glass, which appears to us one uniform substance, is composed of different substances, he tells us, what, with livelier perceptive organs, we might have known, without a single experiment; since the siliceous matter and the alkali were present to us in every piece of glass, as much before he told us of their presence, as after it. The art of analysis, therefore, has its origin in the mere imperfection of our senses, and is truly the art of the blind, whose wants it is always striving to remedy, and always discovering sufficient proof of its inability to remedy them.

We boast, indeed, of the chemical discoveries which we have made of late, with a rapidity of progress as brilliant, as it is unexampled in the history of any other science; and we boast justly, because we have found, what the generations of inquirers that have preceded us on our globe, – far from detecting, – had not even ventured to guess. Without alluding to the agency of the Galvanic power, – by which all nature seems to be assuming before us a different aspect – we have seen fixed in the products of our common fires, and in the drossy rust of metals, the purest part of that ethereal fluid which we breathe, and the air itself, which was so long considered as simple, ceasing to be an element. Yet whatever unsuspected similarities and diversities of composition we may have been able to trace in bodies, all our discoveries have not created a single new particle of matter. They have only shown these to exist, where they always existed, as much before our analysis as after it, – unmarked indeed, but unmarked, only because our senses alone were not capable of making the nice discrimination. If man had been able to perceive, with his mere organs of sense, the different particles that form together the atmospheric air – if he had at all times seen the portion of these which unites with the fuel that warms him, enter into this union, as distinctly as he sees the mass of fuel itself, which he flings into his furnace, he could not have thought it a very great intellectual achievement, to state in words so common and familiar a fact, – the mere well-known change of place of a few well-known particles; and yet this is what, in the imperfect state of his perceptive organs, he so proudly terms his Theory of Combustion, the developement of which was hailed by a wondering world, and in these circumstances justly hailed by it, as a scientific era. To beings, capable of perceiving and distinguishing the different particles, that form by their aggregation, those small masses, which, after the minutest mechanical division of which we are capable, appear atoms to us, the pride which we feel, in our chemical analyses, must seem as ludicrous, as to us would seem the pride of the blind, if one, who had never enjoyed the opportunity of beholding the sun, were to boast of having discovered, by a nice comparison of the changing temperature of bodies, that, during certain hours of the day, there passed over our earth some great source of heat. The addition of one new sense to us, who have already the inestimable advantages which vision affords, might probably, in a few hours, communicate more instruction, with respect to matter, than all which is ever to repay and consummate the physical labours of mankind, – giving, perhaps, to a single glance, those slow revelations of nature, which, one by one, at intervals of many centuries, are to immortalize the future sages of our race.

“All philosophy,” says an acute foreign writer, “is founded on these two things, – that we have a great deal of curiosity, and very bad eyes. In astronomy, for example, if our eyes were better, we should then see distinctly, whether the stars really are, or are not, so many suns, illuminating worlds of their own; and if, on the other hand, we had less curiosity, we should then care a very little about this knowledge, which would come pretty nearly to the same thing. But we wish to know more than we see, and there lies the difficulty. Even if we saw well the little which we do see, this would at least be some small knowledge gained. But we observe it different from what it is; and thus it happens, that a true philosopher passes his life, in not believing what he sees, and in labouring to guess what is altogether beyond his sight. I cannot help figuring to myself,” continues the same lively writer, “that nature is a great public spectacle, which resembles that of the opera. From the place at which we sit in the theatre, we do not see the stage quite as it is. The scenes and machinery are arranged, so as to produce a pleasing effect at a distance; and the weights and pullies, on which the different movements depend, are hid from us. We therefore do not trouble our heads with guessing, how this mechanical part of the performance is carried on. It is perhaps only some mechanician, concealed amid the crowd of the pit, who racks his brain about a flight through the air, which appears to him extraordinary, and who is seriously bent on discovering by what means it has been executed. This mechanic, gazing, and wondering, and tormenting himself, in the pit of the opera, is in a situation very like that of the philosopher in the theatre of the world. But what augments the difficulty to the philosopher, is, that, in the machinery which nature presents, the cords are completely concealed from him, – so completely indeed, that the constant puzzle has been to guess, what that secret contrivance is, which produces the visible motions in the frame of the universe. Let us imagine all the sages collected at an opera, – the Pythagorases, Platos, Aristotles, and all those great names, which now-a-days make so much noise in our ears. Let us suppose, that they see the flight of Phaeton, as he is represented carried off by the winds; that they cannot perceive the cords to which he is attached; and that they are quite ignorant of every thing behind the scenes. It is a secret virtue, says one of them, that carries off Phaeton. Phaeton, says another, is composed of certain numbers, which cause him to ascend. A third says, Phaeton has a certain affection for the top of the stage. He does not feel at his ease, when he is not there. Phaeton, says a fourth, is not formed to fly; but he likes better to fly, than to leave the top of the stage empty, – and a hundred other absurdities of the kind, that might have ruined the reputation of antiquity, if the reputation of antiquity, for wisdom could have been ruined. At last, come Descartes, and some other moderns, who say, Phaeton ascends, because he is drawn by cords, and because a weight, more heavy than he, is descending as a counterpoise. Accordingly, we now no longer believe, that a body will stir, unless it be drawn or impelled by some other body, or that it will ascend, or descend, unless by the operation of some spring or counterpoise; and thus to see nature, such as it really is, is to see the back of the stage at the opera.”[24 - Fontenelle, Pluralité des Mondes, Conversat. 1.]

In this exposition of the phenomena of the universe, and of those strange “follies of the wise,” which have been gravely propounded in the systems of philosophers concerning them, there is much truth, as well as happy pleasantry. As far, at least, as relates to matter, considered merely as existing in space, – the first of the two lights in which it may be physically viewed, – there can be no question, that philosophy is nothing more than an endeavour to repair, by art, the badness of our eyes, that we may be able to see what is actually before us at every moment. To be fairly behind the scenes of the great spectacle of nature, however, is something more than this. It is not merely to know, at any one moment, that there are many objects existing on the stage, which are invisible where the spectators sit, but to know them as pieces of machinery, and to observe them operating in all the wonders of the drama. It is, in short, to have that second view of nature, as existing in time as well as space, to the consideration of which I am to proceed in my next Lecture.

LECTURE VI

THE SAME SUBJECT CONTINUED

In my last Lecture, Gentlemen, I considered, at some length, the nature of Physical Inquiry in general, and stated to you, in particular, the two lights, in which objects may be physically viewed, as existing simply in space, or as existing in time, – the inquiries, with respect to the one, having regard to the composition of bodies; the inquiries, with respect to the other, having regard to the changes, of which they are either the subjects or occasions, and consequently to their susceptibilities or their powers – their susceptibilities of being affected by other substances, their powers of affecting other substances. I use the word susceptibility, you will perceive, as, in this case, synonymous with what Mr Locke, and some other writers, have denominated passive power, to avoid the apparent verbal contradiction, or at least the ambiguity, which may arise from annexing the term passive to a word, which is generally employed to signify, not the subject of change, but the cause or occasion of change.

Of these two points of view, then, in which an object may be regarded, when the question is put, What is it? we have seen, I hope, sufficiently distinctly, the nature of one. If, in answering the question, we regard the object merely as it exists in space, and say, that it is a compound of certain substances, we mean nothing more, than that, in the portion of space, which we conceive to be occupied by this one imaginary aggregate, there is truly a plurality of bodies, which, though seemingly contiguous, have an existence, as separate and independent of each other, as if they were at the most remote distance; the one aggregate being nothing more than a name for these separate bodies, to which ourselves give all the unity which they have, merely by considering them as one.

The necessity of inquiring into the nature of these separate elementary bodies, – which constitutes one of the two great departments of physical investigation, – we found to arise from the imperfection of our senses, that are not sufficiently acute to discover, of themselves, the component parts of the masses, which nature everywhere presents to us. We are thus obliged to form to ourselves an art of analysis, merely that we may perceive what is constantly before our eyes, in the same manner, as we are obliged to have recourse to the contrivances of the optician, to perceive stars and planets, that are incessantly shedding on us their light.

There is, indeed, something truly worthy of our astonishment, in the sort of knowledge of the qualities of matter, which, with our very imperfect senses, we are still able to attain. What we conceive ourselves to know is an aggregate of many bodies, of each of which, individually, we may be said, in the strictest sense of the term, to be absolutely ignorant; and yet the aggregate, which we know, has no real existence, but as that very multitude of bodies, of which we are ignorant. When water was regarded as a simple substance, every one who looked upon a lake or river, conceived that he knew as well what the liquid was which flowed in it, as the chemist, who now considers it as compound; and the chemist, who has learned to regard it as compound, is perhaps as ignorant of the true nature of the separate bodies that exist in it, as those who formerly regarded it as simple; since one additional discovery may prove the very elements, which he now regards as the ultimate constituents of water, to be truly compounded of other elements, still more minute, and now altogether unknown to him.

That our only knowledge of matter should be of a multitude of bodies, of the nature of each of which, individually, we are in absolute ignorance, may seem, at first sight, to justify many of the most extravagant doubts of the sceptic: and yet there is really no ground for such scepticism, since, though the coexisting bodies be separately unknown, the effect, which they produce when coexisting in the circumstances observed by us, is not the less certain and definite; and it is this joint effect of the whole, thus certain and definite, which is the true object of our knowledge; not the uncertain effect, which the minuter elements might produce, if they existed alone. The same aggregates, whatever their elementary nature may be, operate on our senses, as often as they recur, in the same manner; the unknown elements which constitute an oak, or a tower, or the ivy that clings around it, exciting in the mind those particular sensations, to the external causes of which we continue to give the name of oak or tower or ivy; and exciting these, as precisely and uniformly, as if we were acquainted with each minute element of the objects without. Our knowledge of nature must in this way, indeed, be confined to the mixed effects of the masses which it exhibits; but it is not on that account less valuable, nor less sure; for to the certainty of this limited knowledge all which is necessary is uniformity of the mixed effects, whatever their unknown coexisting causes may be. It is with masses only, not with elements that we are concerned, in all the important purposes of life; and the provident wisdom of the Author of Nature, therefore, has in this as in every other case, adapted our powers to our necessities, – giving to all mankind the knowledge, that is requisite for the purposes which all mankind must equally have in view, and leaving to a few philosophic inquirers, the curiosity of discovering what the substances around us truly are in their elementary state, and the means of making continual progress, in this never-ending analysis.

Such then is the nature of one of the views, in which physical inquiry may be directed to the discovery of elements, that are existing together, at the same moment. But is not this species of inquiry, it may be asked, peculiar to matter, or may it also be extended to mind? It is easy to conceive that, if matter always have extension, and therefore necessarily be composed of parts, an inquiry into its composition may form an important part of physical investigation; but this sort of inquiry will seem to you altogether inadmissible in the philosophy of mind, since the mind is not composed of parts that coexist, but is simple and indivisible. If, indeed, the term composition, in this application of it, be understood strictly in the same sense as when applied to matter, it is very evident, that there can be no inquiry into the composition of thoughts and feelings, since every thought and feeling is as simple and indivisible as the mind itself; being, in truth, nothing more than the mind itself existing at a certain moment in a certain state; and yet, in consequence of some very wonderful laws, which regulate the successions of our mental phenomena, the science of mind is, in all its most important respects, a science of analysis, or at least a science which exhibits to our contemplation the same results as if it were strictly analytical; and we inquire into the separate ideas or other feelings, involved in one complex thought or emotion, very nearly as we inquire into the corpuscular elements, that coexist in one seemingly continuous mass. The nature of this very wonderful application of analysis, or at least of a process which is virtually the same as analysis, to a substance, that is necessarily at all times simple and indivisible, will, however, be better understood by you, after we have turned our attention to the other general division of physical inquiry, which is still to be considered by us. I need not I hope, repeat, after the remarks which I made in my last Lecture, that, in leading your thoughts, for so long a time, to the subject of general science, I have had constantly in view its application to the phenomena of our own department of it, and that we are truly learning to study mind with accuracy, when we are learning what it is, which is to be studied in the great system of things. There can be no question at least, that he who has erroneous notions of the objects of physical investigation in the material universe, will be very likely also to err, or rather cannot fail to err, in his notions of the objects of physical investigation, as it relates to mind.

I proceed, then, to consider, what it is which we truly have in view, when we direct our inquiry, not to the mere composition of objects existing continuously in space, but to the succession of changes which they exhibit in time, – to their susceptibility of being affected by other substances, or their power of affecting other substances. The inquiry, as you must perceive, involves the consideration of some words about which a peculiar mystery has been very generally supposed to hang —causation, power, connexion of events. But we shall perhaps find that what is supposed so peculiarly mysterious in them, is not in the very simple notions themselves, but in the misconceptions of those who have treated of them.

It is not in this case, as in the former department of physical investigation, the mere imperfection of our senses, that produces the necessity of inquiry. Matter, as existing in space, is wholly before us, and all which is necessary for perfect knowledge of it, in this respect, is greater delicacy of our perceptive organs, that we may distinguish every element of the seemingly continuous mass. To know the mere composition of a substance, is to know only what is actually present at the very moment, which we may imagine senses of the highest perfection to be capable of instantly perceiving; but to know all the susceptibilities and powers of a substance, the various modes in which it may affect or be affected by every other, is to know it, not merely as it exists before us in the particular circumstances of any one moment, but as it might have existed, or may exist, in all possible circumstances of combination, – which our senses, that are necessarily confined to the circumstances of the present moment, never could teach us, even though they were able to distinguish every atom of the minutest mass.

If, indeed, there were any thing, in the mere appearance of a body, which could enable us to predict the changes that would take place in it, when brought into every possible variety of situation, with respect to other bodies, or the changes which it would then produce in those other bodies, the two views, into which I have divided physical inquiry, would coincide exactly; so that to know the continuous elements of any substance, would be to know, at the same time, its susceptibilities and powers. But there is nothing, in the mere sensible qualities of bodies, considered separately, that can give us even the slightest intimation of the changes, which, in new circumstances of union, they might reciprocally suffer or produce. Who could infer, from the similar appearance of a lump of sugar and a lump of calcareous spar, that the one would be soluble in water, and the other remain unmelted; or, from the different aspect of gunpowder and snow, that a spark would be extinguished, if it fell upon the one, and, if it fell upon the other, would excite an explosion that would be almost irresistable? But for experience, we should be altogether incapable of predicting any such effects, from either of the objects compared; or, if we did know, that the peculiar susceptibility belonged to one of the two, and not the other, we might as readily suppose, that calcareous spar would melt in water as sugar, and as readily, that snow as that gunpowder would detonate, by the contact of a spark. It is experience alone, which teaches us that these effects ever take place, and that they take place, not in all substances, but only in some particular substances.

It has, indeed, been supposed by many ingenious philosophers, that, if we were acquainted with what they term the intimate structure of bodies, we should then see, not merely what corpuscular changes take place in them, but why these changes take place in them; and should thus be able to predict, before experience, the effects which they would reciprocally produce. “I doubt not,” says Locke, “but if we could discover the figure, size, texture, and motion of the minute constituent parts of any two bodies, we should know without trial several of their operations one upon another, as we do now the properties of a square or a triangle. Did we know the mechanical affections of the particles of rhubarb, hemlock, opium, and a man; as a watch-maker does those of a watch, whereby it performs its operations, and of a file, which by rubbing on them will alter the figure of any of the wheels; we should be able to tell before-hand, that rhubarb will purge, hemlock kill, and opium make a man sleep; as well as a watch-maker can, that a little piece of paper laid on the balance will keep the watch from going, till it be removed; or that, some small part of it being rubbed by a file, the machine would quite lose its motion, and the watch go no more. The dissolving of silver in aquafortis, and gold in aqua regia, and not vice versa, would be then perhaps no more difficult to know, than it is to a smith to understand why the turning of one key will open a lock, and not the turning of another. But while we are destitute of senses acute enough to discover the minute particles of bodies, and to give us ideas of the mechanical affections, we must be content to be ignorant of their properties and ways of operation; nor can we be assured about them any farther, than some few trials we make are able to reach. But whether they will succeed again another time, we cannot be certain. This hinders our certain knowledge of universal truths concerning natural bodies: and our reason carries us herein very little beyond particular matter of fact.

“And therefore I am apt to doubt, that how far soever human industry may advance useful and experimental philosophy in physical things, scientifical will still be out of our reach; because we want perfect and adequate ideas of those very bodies which are nearest to us, and most under our command. Those which we have ranked into classes under names, and we think ourselves best acquainted with, we have but very imperfect and incomplete ideas of. Distinct ideas of the several sorts of bodies that fall under the examination of our senses perhaps we may have; but adequate ideas, I suspect, we have not of any one among them. And though the former of these will serve us for common use and discourse, yet while we want the latter, we are not capable of scientifical knowledge; nor shall ever be able to discover general, instructive, unquestionable truths concerning them. Certainty and demonstration are things we must not, in these matters, pretend to. By the colour, figure, taste, and smell, and other sensible qualities, we have as clear and distinct ideas of sage and hemlock, as we have of a circle and a triangle; but having no ideas of the particular primary qualities of the minute parts of either of these plants, nor of other bodies which we would apply them to, we cannot tell what effects they will produce; nor when we see those effects, can we so much as guess, much less know, their manner of production. Thus having no ideas of the particular mechanical affections of the minute parts of bodies that are within our view and reach, we are ignorant of their constitutions, powers, and operations: and of bodies more remote we are yet more ignorant, not knowing so much as their very outward shapes, or the sensible and grosser parts of their constitutions.”[25 - Essay concerning Human Understanding, book iv. c. 3. sec. 25, 26.]

The fallacy of the reasoning of this very eminent philosopher consists partly, in the present case, in a sort of petitio principii, or, at least, a false assumption that is involved in the very phrase mechanical affections, and in all the mechanical illustrations adduced. If rhubarb purge, and hemlock kill, by qualities that can be said to be mechanical, and if these qualities be PERMANENT, there can be no question, that to know accurately the mechanical qualities of these substances, in relation to the human body, would be to know, that rhubarb must purge, and hemlock kill, as much as to know the mechanism of a watch would be to know, that the watch must stop, if a small part of it were rubbed by a file. But the inquiry is still left, whether it be thus, by the mere principles of mechanical action, that rhubarb and hemlock produce their peculiar effects on the animal system, and that silver is dissolved in aqua fortis, and gold in aqua regia; and, if there be no reason whatever to suppose this, we must then surely admit that the prophecy would still be beyond our power, though we were acquainted with “the figure, size, texture, and motion, of the minute constituent parts” of the different bodies. In the same manner, as, in the mechanical division of a substance, we must still come to other substances capable of further division, so, though we could reduce all the changes that appear to be wrought in the great masses around us, to the changes wrought in their minute parts, we must still come to certain ultimate changes as inexplicable as those which we see at present. It is as difficult to predict, without experience, the motion of one atom to or from another atom, as the motion of one mass of atoms to or from another mass of atoms. That the globe of the earth should tend towards the sun, which is at so great a distance from it, and should thus be every moment arrested within that orbit, from which, if there were no such deflecting force, it would every moment have a tendency to escape by flying off in a straight line, is, indeed, most wonderful. But precisely the same laws which operate on the whole globe of the earth, operate on every particle of which the earth is composed, – since the earth itself is only these separate particles under another name; and if it be wonderful that all of these should have a tendency to approach the sun, it must be equally wonderful, that each minute constituent particle should tend individually, though, to use Mr Locke's words, we were accurately acquainted with the “figure, size, texture, and motion of each.” The same original mystery of gravitation, then, would remain, though our senses enabled us to discover every gravitating particle in the intimate structure of the gravitating mass. By knowing the intimate structure of bodies, we should indeed, know what were their elements mutually affected, but not why these elements were mutually affected, or were affected in one way rather than in another.

The chief error of Mr Locke, in this respect, evidently consisted, as I have said, in his assumption of the very thing to be proved, by taking for granted, that all the changes of bodies are the effects of their immediate contact and impulse, and of a kind, therefore, which may be termed strictly mechanical, – an assumption, indeed, which harmonized with the mathematical chemistry and medicine of the age in which he lived, but of the justness of which there is not the slightest evidence in the general phenomena, chemical and nervous, of which he speaks. If, instead of confining his attention to the action of bodies in apparent contact, he had turned his thought to the great distant agencies of nature in the motions of the planetary world, it is scarcely possible to conceive that he should not have discovered his mistake. In another of his works, his Elements of Natural Philosophy, he has stated very justly, as a consequence of the law of gravitation, that if the earth were the sole body in the universe, and at rest, and the moon were suddenly created at the same distance from the earth as at present, the earth and the moon would instantly begin to move towards one another in a straight line. What knowledge of the “figure, size, and texture,” of the particles of the earth could have enabled its human inhabitants to predict this instant change? and if the particles of gold and aqua regia, and of hemlock, rhubarb, and opium, which, together with all the other particles of our globe, would in the case supposed, instantly begin to move towards the moon, – can thus attract and be attracted, in gravitation, with tendencies that are independent of every mechanical affection, what authority can there be for supposing, that the chemical and vital agencies of the same particles must be mechanical, or that the one set of changes could have been predicted a priori, if the other was confessedly beyond the power of philosophic divination?

But even with regard to the mechanical affections of matter themselves, though all the changes which take place in nature were truly reducible to them, we should still have ultimately the same difficulty in attempting to predict, without experience, the changes that would ensue from them. The mechanical properties are indeed the most familiar to our thought, because they are those which we are constantly witnessing in the great displays of human power that are most striking to our senses. The house, the bridge, the carriage, the vessel, every implement which we use, and the whole wide surface of the cultivated earth, present to us, as it were, one universal trophy of the victories of the great mechanist, man. We cannot look back to the time when we were ignorant of the mechanical properties of matter; but still there was a time when they first became known to us, and became known by experience of the motions that resulted from them. What can be simpler than the phenomena of impulse? That a ball in motion, when it meets another at rest, should force this to quit its place, appears now to be something which it required no skill or experience to predict; and yet, though our faculties were, in every respect, as vigorous as now, – if we could imagine this most common of all phenomena to be wholly unknown to us, – what reason should we be able to discover in the circumstances that immediately precede the shock, for inferring the effect that truly results, rather than any other effect whatever? Were the laws of motion previously unknown, it would be in itself as presumable, that the moving ball should simply stop when it reached the other, or that it should merely rebound from it, as that the quiescent ball should be forced by it to quit its state of rest, and move forward in the same direction. We know, indeed, that the effect is different, but it is because we have witnessed it that we know it; not because the laws of motion, or any of the mechanical affections of matter whatever are qualities that might be inferred independently of observation.

Experience, then, is necessary in every case, for discovering the mutual tendencies of the elements of bodies, as much as for determining the reciprocal affections of the masses. But experience teaches us the past only, not the future, and the object of physical inquiry is, not the mere solitary fact of a change which has taken place, but the similar changes which will continually take place as often as the objects are again in the same circumstances, – not the phenomena only, but the powers by which the phenomena are produced.

Why is it, then, we believe that continual similarity of the future to the past, which constitutes, or at least is implied, in our notion of power? A stone tends to the earth, – a stone will always tend to the earth, – are not the same proposition; nor can the first be said to involve the second. It is not to experience, then, alone that we must have recourse for the origin of the belief, but to some other principle, which converts the simple facts of experience into a general expectation, or confidence, that is afterwards to be physically the guide of all our plans and actions.

This principle, since it cannot be derived from experience itself, which relates only to the past, must be an original principle of our nature. There is a tendency in the very constitution of the mind from which the expectation arises, – a tendency that, in every thing which it adds to the mere facts of experience, may truly be termed instinctive; for though that term is commonly supposed to imply something peculiarly mysterious, there is no more real mystery in it than in any of the simplest successions of thought, which are all, in like manner, the results of natural tendency of the mind to exist in certain states, after existing in certain other states. The belief is, a state or feeling of the mind as easily conceivable as any other state of it, – a new feeling, arising in certain circumstances as uniformly as in certain other circumstances. There arise other states or feelings of the mind, which we never consider as mysterious; those, for example, which we term the sensations of sweetness or of sound. To have our nerves of taste or hearing affected in a certain manner, is not, indeed, to taste or to hear, but it is immediately afterwards to have those particular sensations; and this merely because the mind was originally so constituted, as to exist directly in the one state after existing in the other. To observe, in like manner, a series of antecedents and consequents, is not, in the very feeling of the moment, to believe in the future similarity, but, in consequence of a similar original tendency, it is immediately afterwards to believe, that the same antecedents will invariably be followed by the same consequents. That this belief of the future is a state of mind very different from the mere perception or memory of the past, from which it flows, is indeed true; but what resemblance has sweetness, as a sensation of the mind, to the solution of a few particles of sugar on the tongue, – or the harmonies of music, to the vibration of particles of air? All which we know, in both cases, is, that these successions regularly take place; and in the regular successions of nature, which could not, in one instance more than in another, have been predicted without experience, nothing is mysterious, or every thing is mysterious. It is wonderful, indeed, – for what is not wonderful? – that any belief should arise as to a future which as yet has no existence; and which, therefore, cannot, in the strict sense of the word, be an object of our knowledge. But, when we consider Who it was who formed us, it would, in truth, have been more wonderful, if the mind had been so differently constituted that the belief had not arisen; because, in that case, the phenomena of nature, however regularly arranged, would have been arranged in vain, and that Almighty Being, who, by enabling us to foresee the physical events that are to arise, has enabled us to provide for them, would have left the creatures, for whom he has been so bounteously provident, to perish, ignorant and irresolute, amid elements that seemed waiting to obey them, – and victims of confusion, in the very midst of all the harmonies of the universe.

Mr Hume, indeed, has attempted to show, that the belief of the similarity of future sequences of events is reducible to the influence of custom, without the necessity of any intuitive expectation; but he has completely failed in the reasoning with which he has endeavoured to support this opinion. Custom may account for the mere suggestion of one object by another, as a part of a train of images, but not for that belief of future realities, which is a very different state of mind, and which, perhaps, does not follow every such suggestion, however frequent and habitual. The phenomenon A, a stone has a thousand times fallen to the earth; the phenomenon B, a stone will always, in the same circumstances, fall to the earth; are propositions that differ as much as the propositions, A, a stone has once fallen to the earth; B, a stone will always fall to the earth. At whatever link of the chain we begin, we must still meet with the same difficulty – the conversion of the past into the future. If it be absurd to make this conversion at one stage of inquiry, it is just as absurd to make it at any other stage; and, as far as our memory extends, there never was a time at which we did not make the instant conversion, – no period, however early, at which we were capable of knowing that a stone had fallen, and yet believed that, in exactly the same circumstances, there was no reason to suppose that it would fall again. But on this particular error of Mr Hume, the very narrow outline, within which the present sketch is necessarily bounded, will not permit me to enlarge. I have examined it, at considerable length, in the third edition of the Inquiry which I have published on the Relation of Cause and Effect.

It is more immediately our present purpose to consider, What it truly is which is the object of inquiry, when we examine the physical successions of events, in whatever manner the belief of their similarity of sequence may have arisen? Is it the mere series of regular antecedents and consequents themselves? or, Is it any thing more mysterious, which must be supposed to intervene and connect them by some invisible bondage?

We see, in nature, one event followed by another. The fall of a spark on gunpowder, for example, followed by the deflagration of the gunpowder; and, by a peculiar tendency of our constitution, which we must take for granted, whatever be our theory of power, we believe, that as long as all the circumstances continue the same, the sequence of events will continue the same; that the deflagration of gunpowder, for example, will be the invariable consequence of the fall of a spark on it; – in other words, we believe the gunpowder to be susceptible of deflagration on the application of a spark, – and a spark to have the power of deflagrating gunpowder.

There is nothing more, then, understood in the trains of events, however regular, than the regular order of antecedents and consequents which compose the train; and between which, if any thing else existed, it would itself be a part of the train. All that we mean, when we ascribe to one substance a susceptibility of being affected by another substance, is, that a certain change will uniformly take place in it when that other is present; – all that we mean, in like manner when we ascribe to one substance a power of affecting another substance, is, that, when it is present a certain change will uniformly take place in that other substance. Power, in short, is significant not of any thing different from the invariable antecedent itself, but of the mere invariableness of the order of its appearance in reference to some invariable consequent, – the invariable antecedent being denominated a cause, the invariable consequent an effect. To say, that water has the power of dissolving salt, and to say, that salt will always melt when water is poured upon it, are to say precisely the same thing; – there is nothing in the one proposition, which is not exactly, and to the same extent, enunciated in the other.

It would, indeed, be a very different theory of causation, if, without taking into account the important circumstance of invariableness or the uniform certainty of being at all times followed by a particular event, we were to say, that power is mere antecedence; for there can be no question, that phenomena precede other phenomena, which we never consider as having any permanent relation to them. They are regarded as antecedents, but not invariable antecedents, and the reason of this is obvious. Innumerable events are constantly taking place together in the immense system of the universe. There must, therefore, always be innumerable co-existing series, the parts of each of which, though permanently related to each other, may have no permanent relation to the parts of the other series; and one event of one series, may thus precede, not its own effect merely, which is to be its constant and uniform attendant, in all similar circumstances, but the events also of other co-existing series, which may never occur with it again at the same moment. There is no superstition in believing that an eclipse may be followed by a pestilence, or an unpleasant dream by some unforeseen calamity of the day, though there would be much superstition in believing, that these antecedents and consequents had any permanent relation to each other. In ordinary and familiar cases, at least, every one knows sufficiently the distinction of what is thus casual only, and what is invariable in the order of nature. Yet it is only by losing all sight of a distinction so very obvious, and confounding invariable with casual consequences, that Dr Reid, and other eminent philosophers, have been led into much laborious argumentation, in the confidence of confuting one of the simplest and justest of metaphysical opinions. To prove that power is more than invariable antecedence, they prove that it is more than casual antecedence, and that events do not follow each other, loosely and confusedly, as if antecedents could be invariable, which had not consequents as invariable, or, as if an uniform series were not merely another name for a number of uniform antecedents and consequents. A cause is, perhaps, not that which has merely once preceded an event; but we give the name to that which has always been followed by a certain event, is followed by a certain event, and according to our belief, will continue to be in future followed by that event, as its immediate consequent; and causation, power, or any other synonymous words which we may use, express nothing more than this permanent relation of that which has preceded to that which has followed. If this invariableness of succession, past, present, and future, be not that which constitutes one event the effect of another, Dr Reid, at least, has not pointed out any additional circumstance which we must combine with it, in our definition of an effect, though he has shown, indeed, with most abundant evidence, if any evidence at all were necessary, that the antecedents and consequents are not the same; that we use active and passive verbs, in different senses, applying, as might well be supposed, the one to the antecedent, the other to the consequent; that we speak of effects and causes as if truly different, since it is unquestionably not the same thing to follow uniformly a certain change, and to precede uniformly a certain change, and that we never think of giving those names where we do not conceive that there is some permanent relation. But, though these distinctions might be allowed to have irresistible weight, in opposition to the scepticism, if such extravagant scepticism there ever were, which affirmed the sequences of events to be altogether casual and irregular, they are surely of no weight against that simple definition of power, which affirms it to consist in the probability of the invariable sequence. of some event as its immediate consequent; since this very regularity of the sequences, which is supposed by the definition, must, of itself, have given occasion to all those distinctions of thought and language which Dr Reid has adduced.

That one event should invariably be followed by another event, is indeed, it will be allowed, as every thing in nature is, most wonderful, and can be ascribed only to the infinite source of every thing wonderful and sublime; the will of that divine Being, who gave the universe its laws, and who formed these with a most beneficent arrangement for the happiness of his creatures, who, without a belief in the uniformity of these laws, to direct their conduct, could not have known how to preserve even their animal existence. But the uniformity of succession is surely not rendered less wonderful, by a mere change of name. It is the same unaltered wonder still, when we ascribe the term power to the prior of two events, as when we ascribe to it the exactly synonymous phrase invariableness of antecedence; each of these terms implying nothing more than that the one event cannot take place without being immediately followed by the other. The permanence and uniformity of the relation are the essential circumstances. To be that which cannot exist, without being instantly followed by a certain event, is to be the cause of the event, as a correlative effect. It is impossible for us to believe, that the invariable antecedent is any thing but the cause, or the cause any thing but the invariable antecedent; as it is impossible for us to believe that homo is the Latin synonime of man, and yet that man is not the English synonime of homo.

To know the powers of nature, is, then, nothing more than to know what antecedents are and will be invariable, followed by what consequents; for this invariableness, and not any distinct existence, is all which the shorter term power, in any case, expresses; and this, and this alone, is the true object of physical inquiry, in that second point of view, in which we have considered it, as directed to the successions of events.

Whenever, therefore, the question is put, as to any object, What is it? there are two answers, and only two answers, that can be given with meaning. We may regard it as it exists in space, and state the elements that co-exist in it, or rather that constitute it; or we may regard it, as it exists in time, and state, in all the series of changes, of which it forms an invariable part, the objects to which it is related as antecedent or consequent.

To combine these two views of nature, as it exists in space and time, and to know, with perfect accuracy, every element of every aggregate, and every series of changes, of which each forms, or can form, a part, would be to know every thing which can be physically known of the universe. To extend our mere physical inquiry still farther into the phenomena of nature, after this perfect knowledge, would be to suppose erroneously, that, in the compounds before us, of which we know every element, there is some element, not yet discovered, or, in the well-known successions of events, some antecedent or consequent as yet unobserved; or it would be to inquire without any real object of inquiry, – a sort of investigation, which, for two thousand years, was almost the sole employment of the subtile and the studious, and which is far from having perished, with those venerable follies of the schools, at which we know so well how to smile, even while we are imitating them, perhaps, with similar errors of our own. I cannot but think, for example, that, on this very subject of the connexion of events, the prevalent notions and doctrines, even of very eminent philosophers, are not far advanced beyond the verbal complexity of the four causes of which Aristotle treats, the material, the formal, the efficient, and the final; or Plato's five causes, which Seneca, in one of his Epistles, briefly defines the id ex quo, the id a quo, the id quo, the id ad quod, and the id propter quod,[26 - Epist. 65.] and though there were no other evidence than this one subject affords, it would still, I fear, prove sufficiently, that, with all our manifest improvements in our plans of philosophical investigation, and all the splendid discoveries to which these improvements have led, we have not wholly lost that great art, which, for so long a time, supplied the place of the whole art of philosophizing – the art of inquiring assiduously, without knowing what we are inquiring about.

It is an art, indeed, which, there is too much reason to suppose, will accompany philosophy, though always, it is to be hoped, in less and less proportion, during the whole course of its progress. There will forever be points, on which those will reason ill, who may yet reason, with perfect accuracy, on other matters. With all those sublime discoveries of modern times, which do us so much honour, and with that improved art of discovery, which is still more valuable to us than the discoveries produced by it, we must not flatter ourselves with exemption from the errors of darker ages – of ages truly worthy of the name of dark, but to which we perhaps give the name, with more readiness, because it seems to imply, that our own is an age of light. Our real comfort, in comparing ourselves with the irrefragable and subtile doctors of other times, is not that we do not sometimes reason as indefatigably ill as they, and without knowing what we are truly reasoning about, but that we do this much less frequently, and are continually lessening the number of cases, in which we reason as ill, and increasing, in proportion, the number of cases, in which we reason better, and do truly know, what objects we are seeking.

Of all the cases, however, in which it is of importance, that the mind should have precise notions of its objects of inquiry, the most important are those which relate to the subject at present considered by us; because the nature of power, in the relation which it is impossible for us not to feel of events, as reciprocally effects and causes, must enter, in a great measure, into every inquiry which we are capable of making, as to the successive phenomena, either of matter or of mind. It is of so much importance, therefore, to our future inquiries, that you should know what this universal and paramount relation is, that I have dwelt on it at a length, which I fear must have already exhausted your patience; since it is a discussion, I must confess, which requires considerable effort of attention; and which has nothing, I must also confess, to recommend it, but its dry utility. I trust, however, that you are too well acquainted with the nature of science, not to know, that it is its utility which is its primary recommendation; and that you are too desirous of advancing in it, not to disregard the occasional ruggedness of a road, which is far from being always rugged. It may be allowed to him, who walks only for the pleasure of the moment, to turn away from every path, in which he has not flowers and verdure beneath his feet, and beauty wherever he looks around. But what should we have thought of the competitor of the Olympic course, whose object was the glory of a prize, contested by the proudest of his contemporary heroes, if, with that illustrious reward before him, – with strength and agility that might ensure him the possession of it, – and with all the assembled multitudes of Greece to witness his triumph, he had turned away, from the contest, and the victory, because he was not to tread on softness, and to be refreshed with fragrance, as he moved along! In that knowledge which awaits your studies, in the various sciences to which your attention may be turned, you have a much nobler prize before you; and, therefore, I shall not hesitate to call forth occasionally all the vigour of your attention, at the risk of a little temporary fatigue, as often as it shall appear to me, that, by exciting you to more than ordinary intellectual activity, I can facilitate your acquisition of a reward, which the listless exertions of the indolent never can obtain, and which is as truly the prize of strenuous effort, as the Palms of the Circus or the Course.

LECTURE VII

ON POWER, CAUSE, AND EFFECT

My last Lecture, Gentlemen, was chiefly employed in examining what it is, which is the real object of inquiry, when we consider the phenomena of nature as successive; and we found, that, by an original principle of our constitution, we are led, from the mere observation of change, to believe, that, when similar circumstances recur, the changes, which we observed, will also recur in the same order, – that there is hence conceived by us to be a permanent relation of one event, as invariably antecedent, to another event, as invariably consequent, – and that this permanent relation is all which constitutes power. It is a word, indeed, of much seeming mystery; but all which is supposed to be mysterious and perplexing in it vanishes, when it is regarded in its true light as only a short general term, expressive of invariable antecedence, or, in other words, of that, which cannot exist in certain circumstances, without being immediately followed by a certain definite event, which we denominate an effect, in reference to the antecedent, which we denominate a cause. To express, shortly, what appears to me to be the only intelligible meaning of the three most important words in physics, immediate invariable antecedence, is power, – the immediate invariable antecedent, in any sequence, is a cause, – the immediate invariable consequent is the correlative effect.

The object of philosophic inquiry, then, in that second department of it, which we considered with respect to the phenomena of nature as successive, we have found not to be any thing different from the phenomena themselves, but to be those very phenomena, as preceding or following, in certain regular series. Power is not any thing that can exist separately from a substance, but is merely the substance itself, considered in relation to another substance, – in the same manner, as what we denominate form, is not any thing separate from the elementary atoms of a mass, but is merely the relation of a number of atoms, as co-existing in apparent contact. The sculptor at every stroke of his chisel, alters the form of the block of marble on which he works, not by communicating to it any new qualities, but merely by separating from it a number of the corpuscles, which were formerly included by us, in our conception of the continuous whole; and when he has given the last delicate touches that finish the Jupiter, or the Venus, or Apollo, the divine form which we admire, as if it had assumed a new existence beneath the artist's hand, is still in itself unaltered, – the same quiescent mass, that slumbered for ages in the quarry of which it was a part.

Quale fuscæ marmor in Africæ