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

Solo recisum, sumere idoneum
Quoscunque vultus, seu Diana
Seu Cytheræa magis placebit;
Informis, ater, sub pedibus jacet,
Donec politus Phidiaca manu
Formosa tandem destinatæ
Induitur lapis ora divæ.
Jam, jamque poni duritiem placens,
Et nunc ocelli, et gratia mollium
Spirat genarum, nunc labella et
Per nivium coma sparsa collum.

The form of bodies is the relation of their elements to each other in space, – the power of bodies is their relation to each other in time; and both form and power, if considered separately from the number of elementary corpuscles, and from the changes that arise successively, are equally abstractions of the mind, and nothing more. In a former Lecture, I alluded to the influence of errors with respect to the nature of abstraction, as one of the principal causes that retard the progress of philosophy. We give a name to some common quality of many substances; and we then suppose, that there is in it something real, because we have given it a name, and strive to discover, what that is in itself, which, in itself, has no existence. The example, which I used at that time, was the very striking one, of the genera, and species, and the whole classes of ascending and descending universals of the schools. I might have found an example, as striking, in those abstractions of form and power, which we are now considering, – abstractions, that have exercised an influence on philosophy, as injurious as the whole series of universals in Porphyry's memorable tree, and one of which, at least, still continues to exercise the same injurious influence, when the tree of Porphyry has been long disregarded, and almost forgotten.

In the philosophy of Aristotle, form, which all now readily allow to be a mere abstraction of the mind, when considered separately from the figured substance, was regarded as something equally real with matter itself; and indeed, matter, which was supposed to derive from form all its qualities, was rather the less important of the two. Of substantial forms, however, long so omnipotent, we now hear, only in those works which record the errors of other ages, as a part of the history of the fallible being, man, or in those higher works of playful ridicule, which convert our very follies into a source of amusement, and find abundant materials, therefore, in what was once the wisdom of the past. Crambé, the young companion of Martinus Scribblerus, we are told, “regretted extremely, that substantial forms, a race of harmless beings, which had lasted for many years, and afforded a comfortable subsistence to many poor philosophers, should be now hunted down like so many wolves, without the possibility of a retreat. He considered that it had gone much harder with them, than with essences, which had retired from the schools, into the apothecaries' shops, where some of them had been advanced into the degree of quintessences. He thought there should be a retreat for poor substantial forms among the Gentlemen Ushers at Court, and that there were indeed substantial forms, such as forms of Prayer and forms of Government, without which the things themselves could never long subsist.”[27 - Mart. Scrib. c. 7. – Pope's Works, Ed. 1757, v. vii. p. 58, 59.]

The subject of this pleasantry is, indeed, it must be owned, so absurd in itself, as scarcely to require the aid of wit, to render it ridiculous; and yet this more than poetic personification of the mere figure of a body, as itself a separate unity, which appears to us too absurd almost to be feigned as an object of philosophic belief, even to such a mind as that of Crambé, was what, for age after age, seemed to the most intelligent philosophers a complete explanation of all the wonders of the universe; and substantial forms, far from needing a retreat among Gentlemen Ushers at Court, had their place of highest honours amid Doctors and Disputants, in every School and College, where, though they certainly could not give science, they at least served the temporary purpose of rendering the want of it unfelt, and of giving all the dignity which science itself could have bestowed.

The vague and obscure notions, at present attached to the words power, cause, effect, appear to me very analogous to the notions of the Peripatetics, and, indeed, of the greater number of the ancient philosophers, with respect to form; and, I trust that as we have now universally learned to consider form, as nothing in itself, but only as the relation of bodies co-existing immediately in space, so power will at length be as universally considered as only the relation which substances bear to each other in time, according as their phenomena are immediately successive; the invariable antecedent being the cause, the invariable consequent the effect; and the antecedent and consequent being all that are present in any phenomenon. There are, in nature, only substances; and all the substances in nature, are every thing that truly exists in nature. There is, therefore, no additional power, separate, or different from the antecedent itself, more than there is form, separate or different from the figured mass, or any other quality, without a substance. In the beautiful experiment of the prismatic decomposition of light, for example, the refracting power of the prism is not any thing separate or separable from it, more than its weight or transparency of colour. There are not a prism and transparency, but there is a prism giving passage to light. In like manner, there are not a prism, and refracting power, and coloured rays, but there are a prism and rays of various colours, which we have perceived to be deflected variously from their original line of direction, when they approach and quit the lens, and which we believe, will, in the same circumstances, continually exhibit the same tendency.

It is the mere regularity of the successions of events, not any additional and more mysterious circumstance, which power may be supposed to denote, that gives the whole value to our physical knowledge. It is of importance for us to know, what antecedents truly precede what consequents; since we can thus provide for that future, which we are hence enabled to foresee, and can, in a great measure, modify, and almost create, the future to ourselves, by arranging the objects over which we have command, in such a manner, as to form with them the antecedents, which we know to be invariably followed by the consequents desired by us. It is thus we are able to exercise that command over nature, which He, who is its only real Sovereign, has designed, in the magnificence of His bounty, to confer on us, together with the still greater privilege of knowing that Omnipotence to which all our delegated empire is so humbly subordinate. It is a command which can be exercised by us, only as beings, who, according to one of the definitions that have been given of man, look both before and behind; or, in the words of Cicero, who join and connect the future with the present, seeing things, not in their progress merely, but in the circumstances that precede them, and the circumstances that follow them, and being thus enabled to provide and arrange whatever is necessary for that life, of which the whole course lies open before us. “Homo autem (quod rationis est particeps, per quam consequentia cernit, causas rerum videt, earumque progressus et quasi antecessiones non ignorat, similitudines comparat, et rebus præsentibus adjungit atque annectit futuras) facile totius vitæ cursum videt, ad eamque degendam præparat res necessarias.”[28 - Cicero de Officiis, lib. i. c. 4.]

That power is nothing more than the relation of one object or event as antecedent to another object or event, though its immediate and invariable consequent, may, perhaps, from the influence of former habits of thought, or rather, of former abuse of language, at first appear to you an unwarrantable simplification; for, though you may never have clearly conceived, in power, any thing more than the immediate sequence of a certain change or event, as its uniform attendant, the mere habit of attaching to it many phrases of mystery, may, very naturally, lead you to conceive, that, in itself, independently of these phrases, there must be something peculiarly mysterious. But the longer you attend to the notion, the more clearly will you perceive, that all which you have ever understood in it, is the immediate sequence of some change with the certainty of the future recurrence of this effect, as often as the antecedent itself may recur in similar circumstances. To take an example, which I have already repeatedly employed, when a spark falls upon gunpowder, and kindles it into explosion, every one ascribes to the spark the power of kindling the inflammable mass. But let any one ask himself, what it is which he means by the term, and, without contenting himself with a few phrases that signify nothing, reflect, before he give his answer, and he will find, that he means nothing more than that, in all similar circumstances, the explosion of gunpowder will be the immediate and uniform consequence of the application of a spark. To take an example more immediately connected with our own science, we all know, that as soon as any one, in the usual circumstances of health and freedom, wills to move his arm, the motion of his arm follows; and we all believe, that, in the same circumstance of health, and in the same freedom from external restraint, the same will to move the arm, will be constantly followed by the same motion. If we knew and believed nothing more, than that this motion of the arm would uniformly follow the will to move it, would our knowledge of this particular phenomenon be less perfect, than at present, and should we learn any thing new, by being told, that the will would not merely be invariably followed by the motion of the arm, but that the will would also have the power of moving the arm; or would not the power of moving the arm be precisely the same thing, as the invariable sequence of the motion of the arm, when the will was immediately antecedent?

This test of identity, as I have said in my Essay on the subject, appears to me to be a most accurate one. When a proposition is true, and yet communicates no additional information, it must be of exactly the same import, as some other proposition, formerly understood and admitted. Let us suppose ourselves, then, to know all the antecedents and consequents in nature, and to believe, not merely that they have once or repeatedly existed in succession, but that they have uniformly done so, and will continue forever to recur in similar series, so that, but for the intervention of the Divine will, which would be itself, in that case, a new antecedent, it will be absolutely impossible for any one of the antecedents to exist again, in similar circumstances, without being instantly followed by its original consequent. If an effect be something more than what invariably follows a particular antecedent, we might, on the present supposition, know every invariable consequent of every antecedent, so as to be able to predict, in their minutest circumstance, what events would forever follow every other event, and yet have no conception of power or causation. We might know, that the flame of a candle, if we hold our hand over it, would be instantly followed by pain and burning of the hand, – that, if we ate or drank a certain quantity, our hunger and thirst would cease: – we might even build houses for shelter, sow and plant for sustenance, form legislative enactments for the prevention or punishment of vice, and bestow rewards for the encouragement of virtue; – in short, we might do, as individuals and citizens, whatever we do at this moment, and with exactly the same views, and yet, (on the supposition that power is something different from that invariable antecedence which alone we are supposed to know,) we might with all this unerring knowledge of the future, and undoubting confidence in the results which it was to present, have no knowledge of a single power in nature, or of a single cause or effect. To him who had previously kindled a fire, and placed on it a vessel full of water, with the certainty that the water, in that situation, would speedily become hot, what additional information would be given, by telling him that the fire had the power of boiling water, that it was the cause of the boiling, and the boiling its effect? And, if no additional information would in this case be given, then, according to the test of this identity of propositions, before stated, to know events as invariably antecedent and consequent, is to know them as causes and effects; and to know all the powers of every substance therefore, would be only to know what changes or events would, in all possible circumstances, ensue, when preceded by certain other changes or events. It is only by confounding casual with uniform and invariable antecedence, that power can be conceived, to be something different from antecedence. It certainly is something very different from the priority of a single moment; but it is impossible to form any conception of it whatever, except merely as that which is constantly followed by a certain effect.

Such is the simple, and, as it appears to me, the only intelligible view of power, as discoverable in the successive phenomena of nature. And yet, how different from this simple view is the common, or, I may almost say, the universal notion of the agencies, which are supposed to be concerned in the phenomena that are the objects of philosophic inquiry. It is the detection of the powers of nature, to which such inquiry is supposed to lead, – but not of powers, in the sense in which alone that phrase is intelligible, as signifying the objects themselves which uniformly precede certain changes. The powers which our investigation is to detect, or which, at least, in all the phenomena that come under our observation, we are to consider as the sole efficient, though invisible producers of them, are conceived by us to be something far more mysterious, – something that is no part of the antecedent, and yet is a part of it, – or that intervenes between each antecedent and consequent, without being itself any thing intermediate, – as if it were possible that any thing could intervene in a series, without instantly becoming itself a part of the series, – a new link in the lengthened chain, – the consequent of the former antecedent, and the antecedent of the former consequent.

To me, indeed, it appears so very obvious a truth, that the substances which exist in nature – the world, its living inhabitants, and the adorable Being who created them, – are all the real existences in nature, and that, in the various changes which occur, therefore, there can as little be any powers or susceptibilities different from the antecedents and consequents themselves, as there can be forms different from the co-existing particles which constitute them, – that to labour thus to impress this truth upon your minds, seems to me almost like an attempt to demonstrate a self-evident proposition. An illusion, however, so universal, as that which supposes the powers of nature, to be something more, than the mere series of antecedents themselves, is not rashly, or without very full inquiry, to be considered as an illusion; and, at any rate, in the case of a mistake, so prevalent and so important in its consequences, it cannot be uninteresting, to inquire into the circumstances, that appear most probably to have led to it. Indeed the more false, and the more obviously false the illusion is, the more must it deserve our inquiry, what those circumstances have been which have so long obtained for it the assent, not of common understanding merely, but of the quick-sighted and the subtile. For a full view of my opinions on this subject, I must refer you to the work which I have published on the Relation of Cause and Effect; and the short abstract of them which I now offer, as it would be superfluous for those who have read and understood that work, is chiefly for the sake of those who may not have had an opportunity of perusing the volume itself.

One source of the general fallacy unquestionably is that influence of abstraction, to which I before alluded, as aided, and in a great measure perpetuated, by the use of language, and the common unavoidable modes of grammatical construction. We speak of the powers of a substance, of substances that have certain power – of the figure of a body, or of bodies that have a certain figure, in the same manner as we speak of the students of a university, or of a house that has a great number of lodgers; and we thus learn to consider the power, which a substance possesses, as something different from the substance itself, inherent in it indeed, but inherent, as something that may yet subsist separately. In the ancient philosophy, this error extended to the notions both of form and power. In the case of form, however, we have seen, that the illusion, though it lasted for many ages, did at length cease, and that no one now regards the figure of a body, as any thing but the body itself. It is probable that the illusion, with respect to power, as something different from the substance that is said to possess it, would, in like manner, have ceased, and given place to juster views, if it had not been for the cause, which I am next to consider.

This cause is the imperfection of our senses, the same cause which, in the other department of physics before examined by us, – the department, that relates to matter considered merely as existing in space, – we find to give occasion to all our inquiries into the compositions of bodies. In this department of physics, however, which relates to the successions of phenomena in time, the imperfection of our senses operates in a different way. It is not that which gives occasion to the necessity of inquiry; for we have seen, that senses, of the utmost accuracy and delicacy, could not, of themselves, and without experience, have enabled us to predict any one event, in the innumerable series of phenomena that are constantly taking place around us. But, though senses of the nicest discrimination could not have rendered inquiry into the successions of events superfluous, they would have saved us from much idle inquiry, and have given far greater precision, if not to our rules, at least to our uniform practice, of philosophizing.

As our senses are at present constituted, they are too imperfect, to enable us to distinguish all the elements, that co-exist in bodies, and of elements, which are themselves unknown to us, the minute changes which take place in them, must of course be unknown. We are hence, from our incapacity of discovering these elements by our imperfect senses, and imperfect analysis, incapable of distinguishing the whole series of external changes that occur in them, – the whole progressive series of antecedents and consequents in a phenomenon that appears to our senses simple; and, since it is only between immediate antecedents and consequents, that we suppose any permanent and invariable relation, we are therefore constantly on the watch, to detect, in the more obvious changes that appear to us in nature, some of those minuter elementary changes, which we suspect to intervene. These minute invisible changes, when actually intervening, are truly what connect the obvious antecedents with the obvious consequents; and the innumerable discoveries, which we are constantly making of these, lead us habitually to suppose, that, amid all the visible changes perceived by us, there is something latent which links them together. He who for the first time listens to the delightful sounds of a violin, if he be ignorant of the theory of sound, will very naturally suppose that the touch of the strings by the bow is the cause of the melody which he hears. He learns, however, that this primary impulse would be of little effect, were it not for the vibrations excited by it in the violin itself; and another discovery, still more important, shews him that the vibration of the instrument would be of no effect, if it were not for the elastic medium, interposed, between his ear and it. It is no longer to the violin, therefore, that he looks, as the direct cause of the sensation of sound, but to the vibrating air; nor will even this be long considered by him as the cause, if he turns his attention to the structure of the organ of hearing. He will then trace effect after effect, through a long series of complex and very wonderful parts, till he arrive at the auditory nerve, and the whole mass of the brain, – in some unknown state of which he is at length forced to rest, as the cause or immediate antecedent, of that affection of the mind, which constitutes the particular sensation. To inquire into the latent causes of events is thus to endeavour to observe changes which we suppose to be actually taking place before us unobserved, very nearly in the same manner, as to inquire into the composition of a substance is to strive to discover the bodies that are constantly before us, without our being able to distinguish them.

It is quite impossible, that this constant search, and frequent detection of causes, before unknown, thus found to intervene between all the phenomena observed by us, should not, by the influence of the common principles of our mental constitution, at length associate, almost indissolubly, with the very notion of changes as perceived by us, the notion of something intermediate, that as yet lies hid from our search, and connects the parts of the series which we at present perceive. This latent something, supposed to intervene between the observed antecedent and the observed consequent, being the more immediate antecedent of the change which we observe, is of course regarded by us as the true cause of the change, while the antecedent actually observed by us, and known, ceases, for the same reason, to be regarded as the cause, and a cause is hence supposed by us, to be something very mysterious; since we give the name, in our imagination, to something of the nature of which we must be absolutely ignorant, as we are, by supposition, ignorant of its very existence. The parts of a series of changes, which we truly observe, are regarded by us as little more than signs of other intervening changes as yet undetected; and our thought is thus constantly turned from the known to the unknown, as often as we think of discovering a cause.

The expectation of discovering something intermediate and unknown between all known events, it thus appears, is very readily convertible into the common notion of power, as a secret and invisible tie. Why does it do this? or, How does it produce this effect? is the question which we are constantly disposed to put, when we are told of any change which one substance occasions in another; and the common answer, in all such cases, is nothing more than the statement of some intervening object, or event, supposed to be unknown to the asker, but as truly a mere antecedent in the sequence, as the more obvious antecedent which he is supposed to know. How is it that we see objects at a distance – a tower, for example, on the summit of a hill, on the opposite side of a river? Because rays of light are reflected from the tower to the eye. The new antecedent appears to us a very intelligible reason. And why do rays of light, that fall in confusion from every body, within our sphere of vision, on every point of the surface of the eye, – from the wood, the rock, the bridge, the river, as well as the tower, – give distinct impressions of all these different objects? Because the eye is formed of such refracting power, that the rays of light, which fall confusedly on its surface, converge within it, and form distinct images of the objects from which they come, on that part of the eye which is an expansion of the nerve of sight. Again we are told only of intervening events before unknown to us; and again we consider the mere knowledge of these new antecedents as a very intelligible explanation of the event which we knew before. This constant statement of something intermediate, that is supposed to be unknown to us, as the cause of the phenomena which we perceive, whenever we ask, how or why they take place? continually strengthens the illusion, which leads us to regard the powers of objects as something different from the perceived objects themselves; – and yet it is evident, that to state intervening changes, is only to state other antecedents, – not any thing different from mere antecedence, – and that whatever number of these intervening changes we may discover between the antecedent and the consequent, which we at present know, we must at length come to some ultimate change, which is truly and immediately antecedent to the known effect. We may say, that an orator, when he declaims, excites the sensation of sound, because the motion of his vocal organs excites vibrations in the intervening air, – that these vibrations of air are the cause of the sound, by communicating vibration to parts of the ear, and that the vibrations of these parts of the ear are the cause of the sound, by affecting in a particular manner the nerve of hearing, and the brain in general; – but, when we come to the ultimate affection of the sensorial organ, which immediately precedes the sensation of the mind, it is evident, that we cannot say of it, that it is the cause of the sound, by exciting any thing intermediate, since it then could not itself be that by which the sound was immediately preceded. It is the cause, however; exactly in the same manner as all the other parts of the sequence were causes, merely by being the immediate and invariable antecedent of the particular effect. If, in our inability of assigning any thing intermediate, we were to say, that this last affection of the sensorial organ occasioned the sound, because it had the power of occasioning sound, we should say nothing more than if we had said at once, that it occasioned the sound, or, in other words, was that which could not exist in the same circumstances without the sound as its instant attendant.

“What is there,” says Malebranche, “which Aristotle cannot at once propose and resolve, by his fine words of genus, species, act, power, nature, form, faculties, qualities, causa per se, causa per accidens? His followers find it very difficult to comprehend that these words signify nothing; and that we are not more learned than we were before, when we have heard them tell us, in their best manner, that fire melts metals, because it has a solvent faculty; and that some unfortunate epicure, or glutton digests ill, because he has a weak digestion, or because the vis concoctrix does not perform well its functions.”[29 - Recherche de la veritè, liv iv. c. ii. – Vol. II. p. 322.]

We see only parts of the great sequences that are taking place in nature; and it is on this account we seek for the causes of what we know in the parts of the sequences that are unknown. If our senses had originally enabled us to discriminate every element of bodies, and consequently, all the minute changes which take place in these, as clearly as the more obvious changes at present perceived by us; in short, if, between two known events, we had never discovered any thing intermediate and unknown, forming a new antecedent of the consequent observed before, our notion of a cause would have been very different from that mysterious unintelligible something which we now conceive it to be; and we should then, perhaps, have found as little difficulty in admitting it to be what it simply and truly is, – only another name for the immediate invariable antecedent of any event, – as we now find in admitting the form of a body, to be only another name for the relative position of the parts that constitute it.

But, – I have said in my Essay, – though the powers of created things be nothing more than their relation to certain events that invariably attend them, is this definition consistent with the notion which we form of the power of the Creator? or, Is not his efficiency altogether different in nature, as well as in degree? The omnipotence of God, it must, indeed, be allowed, bears to every created power the same relation of awful superiority, which his infinite wisdom and goodness bear to the humble knowledge and virtue of his creatures. But as we know his wisdom and goodness, only by knowing what that human wisdom and goodness are, which, with all their imperfection, he has yet permitted to know and adore him, – so, it is only by knowing created power, weak and limited as it is, that we can rise to the contemplation of his omnipotence. In contemplating it, we consider only his will, as the direct antecedent of those glorious effects which the universe displays. The power of God is not any thing different from God; but is the Almighty himself, willing whatever seems to him good, and creating or altering all things by his very will to create or alter. It is enough for our devotion to trace every where the characters of the Divinity, – of provident arrangement prior to this system of things, – and to know, therefore, that, without that divine will as antecedent, nothing could have been. Wherever we turn our eyes, – to the earth – to the heavens – to the myriads of beings that live and move around us – or to those more than myriads of worlds, which seem themselves almost like animated inhabitants of the infinity through which they range, – above us, beneath us, on every side, we discover, with a certainty that admits not of doubt, intelligence and design, that must have preceded the existence of every thing which exists. Yet, when we analyse those great, but obscure, ideas which rise in our mind, while we attempt to think of the creation of things, we feel, that it is still only a sequence of events which we are considering, – though of events, the magnitude of which allows us no comparison, because it has nothing in common with those earthly changes which fall beneath our view. We do not see any third circumstance existing intermediately, and binding, as it were, the will of the Omnipotent Creator to the things which are to be; we conceive only the divine will itself, as if made visible to our imagination, and all nature at the very moment rising around. It is evident, that in the case of the divine agency, as well as in every other instance of causation, the introduction of any circumstance, as a bond of closer connexion, would only furnish a new phenomenon to be itself connected; but even though it were possible to conceive the closer connexion of such a third circumstance, as is supposed to constitute the inexplicable efficiency between the will of the Creator and the rise of the universe, it would diminish, indeed, but it certainly cannot be supposed to elevate, the majesty of the person, and of the scene. Our feeling of his omnipotence is not rendered stronger by the elevation of the complicated process; it is, on the contrary, the immediate succession of the object to the desire, which impresses the force of the omnipotence on our mind; and it is to the divine agency, therefore, that the representation of instant sequence seems peculiarly suited, as if it were more emphatically powerful. Such is the great charm of the celebrated passage of Genesis, descriptive of the creation of light. It is from stating nothing more than the antecedent and consequent, that the majestic simplicity of the description is derived. God speaks, and it is done. We imagine nothing intermediate. In our highest contemplation of His power, we believe only, that, when He willed creation, a world arose; and that, in all future time, His will to create cannot exist, without being followed by the instant rise into being of whatever He may have willed; that His will to destroy any thing, will be, in like manner, followed by its non-existence; and His will to vary the course of things, by miraculous appearances. The will is the only necessary previous change; and that Being has almighty power, whose every will is immediately and invariably followed by the existence of its object.

LECTURE VIII

ON HYPOTHESIS AND THEORY

The observations which I have already made on power, Gentlemen, have, I hope, shown you, both what it truly is, and the sources of that illusion, which leads us to regard it as something more mysterious.

The principal source of this illusion, we found to be our incapacity of distinguishing the minute elements of bodies, – that leads us, in a manner, which it is unnecessary now to recapitulate, to suspect constantly some intermediate and unobserved objects and events, between the parts of sequences, which we truly observe, and, by the influence of this habit, to transfer, at least, the notion of power, from the antecedent which we observe, to the supposed more direct antecedent, which we only imagine, and to consider the causes of events as some unknown circumstances, that exist between all the antecedents which we know, and the consequents which we know, and connect these together in mysterious union.

The same imperfection of our senses, which, from our incapacity of discovering all the minute elements, and consequently all the minute elementary changes, in bodies, leads us to form erroneous notions of power and causation, has tended, in like manner, to produce a fondness for hypotheses, which, without rendering the observed phenomena, in any respect, more intelligible, only render them more complicated, and increase the very difficulty, which they are supposed to diminish.

Of this tendency of the mind, which is a very injurious one to the progress of sound philosophy, I must request your attention to a little fuller elucidation. To know well, what hypotheses truly are in themselves, and what it is which they contribute to the explanation of phenomena, is, I am convinced, the surest of all preservatives against that too ready assent, which you might otherwise be disposed to give to them; and to guard you from the ready adoption of such loose conclusions, in the reasonings of others, and from the tendency to similar rashness of arrangement and inference, in your own speculative inquiries, is to perform for you the most important office that can be performed, for the regulation, both of your present studies, and of those maturer investigations, to which, I trust, your present studies are to lead.

I have also endeavoured to point out to you, in what manner we are led to believe, that we explain the sequence of two events, by stating some intermediate event. If asked, How it is that we hear a voice at a distance, or see a distant object? we immediately answer, Because the primary vibration of the organs of speech is propagated in successive vibrations through the intervening air, and because light is reflected or emitted from the distant object to the eye; and he who hears this answer, which is obviously nothing more than the statement of another effect, or series of effects, that takes place before that particular effect, concerning which the question is put, is perfectly satisfied, for the time, with the acquisition which he has made, and thinks, that he now knows, how it is, that we hear and see. To know why a succession of events takes place, is thus at length conceived by us, to be the same thing, as to know some other changes, or series of changes, which take place between them; and, with this opinion, as to the necessary presence of some intervening and connecting link, it is very natural, that, when we can no longer state or imagine any thing which intervenes, we should feel as if the sequence itself were less intelligible, though unquestionably, when we can state some intervening circumstance, we have merely found a new antecedent in the train of physical events, so as to have now two antecedents and consequents, instead of one simple antecedent and consequent, and have thus only doubled our supposed mystery, instead of removing it.

Since it does appear to us, however, to remove the very mystery which it doubles, it is the same thing, with respect to our general practice of philosophizing, as if it did remove it. If we suppose the intervention of some unknown cause, in every phenomenon which we perceive, we must be equally desirous of discovering that unknown cause, which we suppose to be intermediate, – and, when this is not easily discoverable, we must feel a strong tendency to divine what it is, and to acquiesce, more readily than we should otherwise have done, in the certainty of what we have only imagined, – always, of course, imagining the cause, which seems to have most analogy to the observed effect.

Such is the nature of that illusion, from which the love of hypotheses flows, – as seeming, by the intervention of a new antecedent, to render more intelligible the sequences of events that are obviously before us, – though all which is truly done, is to double the number of antecedents; and, therefore, to double, instead of removing the difficulty, that is supposed to be involved in the consideration of a simple sequence of events. A stone tends to the ground – that it should have this tendency, in consequence of the mere presence of the earth, appears to us most wonderful; and we think, that it would be much less wonderful, if we could discover the presence, though it were the mere presence, of something else. We therefore, in our mind, run over every circumstance analogous, to discover something which we may consider as present, that may represent to our imagination the cause which we seek. The effect of impulse, in producing motion, we know by constant experience; and, as the motion, which it produces, in a particular direction, seems analogous to the motion of the stone in its particular direction, we conceive, that the motion of a stone, in its fall to the earth, is rendered more intelligible, by the imagined intervention of some impelling body. The circumstances, which we observe, however, are manifestly inconsistent with the supposition of the impulse of any very gross matter. The analogies of gross matter are accordingly excluded from our thoughts, and we suppose the impulse to proceed from some very subtle fluid, to which we give the name of ether, or any other name, which we may choose to invent for it. The hypothesis is founded, you will observe, on the mere analogy of another species of motion, and which would account for gravitation by the impulse of some fine fluid. It is evident, that there may be, in this way, as many hypotheses to explain a single fact, as there have been circumstances analogous observed in all the various phenomena of nature. Accordingly, another set of philosophers, instead of explaining gravitation by the analogy of impulse, have had recourse to another analogy, still more intimately familiar to us – that of the phenomena of life: We are able to move our limbs by our mere volition. The mind, therefore, it is evident, can produce motion in matter; and it is hence some interposed spiritual agent, which produces all the phenomena of gravitation. Every orb, in its revolution on its axis, or in its great journey through the heavens, has, according to this system of philosophical mythology, some peculiar genius, or directing spirit, that regulates its course, in the same manner as, of old, the universe itself was considered as one enormous animal, performing its various movements by its own vital energies. It is the influence of this analogy of our own muscular motions, as obedient to our volition, – together with the mistaken belief of adding greater honour to the divine Omnipotent, – which has led a very large class of philosophers to ascribe every change in the universe, material or intellectual, not to the original foresight and arrangement merely, – the irresistible evidence of which even the impiety, that professes to question it, must secretly admit, – but to the direct operation of the Creator and Sovereign of the world, —

“The mighty Hand,
That, ever busy, wheels the silent spheres,
Works in the secret deep; shoots streaming thence
The fair profusion that o'erspreads the spring;
Flings from the sun direct the flaming day;
Feeds every creature; hurls the tempest forth;
And, as on earth this grateful change revolves,
With transport touches all the springs of life.”

So prone is the mind to complicate every phenomenon, by the insertion of imagined causes, in the simple sequences of physical events, that one hypothesis may often be said to involve in it many other hypotheses, invented for the explanation of that very phenomenon, which is adduced in explanation of another phenomenon, as simple as itself. The production of muscular motion by the will, which is the source of the hypothesis of direct spiritual agency, in every production of motion, or change, in the universe, has itself given occasion to innumerable speculations of this kind. Indeed, on no subject has the imagination been more fruitful of fancies, that have been strangely given to the world under the name of philosophy. Though you cannot be supposed to be acquainted with the minute nomenclature of anatomy, you yet all know, that there are parts termed muscles, and other parts termed nerves, and that it is by the contraction of our muscles that our limbs are moved. The nerves, distributing to the different muscles, are evidently instrumental to their contraction; since the destruction of the nerve puts an end to the voluntary contraction of the muscle, and consequently to the apparent motion of the limb. But what is the influence that is propagated along the nerve, and in what manner is it propagated? For explaining this most familiar of all phenomena, there is scarcely any class of phenomena in nature, to the analogy of which recourse has not been had, – the vibration of musical chords, – the coiling or uncoiling of springs, – the motion of elastic fluids, electricity, magnetism, galvanism; – and the result of so many hypotheses, – after all the labour of striving to adapt them to the phenomena, and the still greater labour of striving to prove them exactly adapted, when they were far from being so – has been the return to the simple fact, that muscular motion follows a certain state of the nerve; – in the same manner, as the result of all the similar labour, that has been employed to account, as it has been termed, for gravitation, has been a return to the simple fact, that, at all visible distances observed, the bodies in nature tend toward each other.

The mere sequence of one event after another event, is, however, too easily conceived, and has too little in it of that complication, which at once busies and delights us, to allow the mind to rest in it long. It must forever have something to disentangle, and, therefore, something which is perplexed; for, such is the strange nature of man, that the simplicity of truth, which might seem to be its essential charm, – and which renders it doubly valuable, in relation to the weakness of his faculties, – is the very circumstance that renders it least attractive to him; and though, in his analysis of every thing that is compound in matter, or involved in thought, he constantly flatters himself, that it is this very simplicity, which he loves and seeks, he yet, when he arrives at absolute simplicity, feels an equal tendency to turn away from it, and gladly prefers to it any thing that is more mysterious, merely because it is mysterious. “I am persuaded,” said one, who knew our nature well, “that, if the majority of mankind could be made to see the order of the universe, such as it is, as they would not remark in it any virtues attached to certain numbers, nor any properties inherent in certain planets, nor fatalities, in certain times and revolutions of these, they would not be able to restrain themselves, on the sight of this admirable regularity and beauty, from crying out with astonishment, What, is this all?”

For the fidelity of this picture, in which Fontenelle has so justly represented one of the common weaknesses of our intellectual nature, we unfortunately need not refer to the majority of mankind alone, to whom, it may be said, almost with equal truth, that every thing is wonderful, and that nothing is wonderful. The feeling which it describes exists even in the most philosophic mind, and had certainly no increased influence even on that mind which described it so truly, when it employed all its great powers, in still striving to support the cumbrous system of the Vortices, against the simple theory of attraction. Even Newton himself, whose transcendent intellect was so well fitted to perceive the sublimity, which simplification adds to every thing that is truly great in itself, yet, showed, by his query with respect to the agency of ether, that he was not absolutely exempt from that human infirmity of which I speak; and though philosophers may now be considered as almost unanimous with respect to gravitation, – in considering it as the mere tendency of bodies towards each other, we yet, in admiring this tendency which we perceive, feel some reluctance to admit a mere fact, that presents itself so simply to our conception, and would be better pleased, if any other mode could be pointed out, by which, with some decent appearance of reason on its side, the same effect could seem to be brought about, by a natural apparatus, better suited to gratify our passion for the complicated and the wonderful. Though the theory of Vortices can scarcely be said now to have any lingering defender left, there is a constant tendency, and a tendency which requires all our philosophy to repress it, – to relapse into the supposition of a great etherial fluid, by the immense ocean, or immense streams, of which the phenomenon now asserted to gravitate, may be explained, and we have no objection, to fill the whole boundless void of the universe, with an infinite profusion of this invisible matter, merely that we may think, with more comfort, that we know how a feather falls to the ground; – though the fall of the feather, after this magnificent cast of contrivance, would still be as truly inexplicable as at present; and though many other difficulties must, in that case, be admitted in addition. It is only in geometry, that we readily allow a straight line, to be the shortest that can be drawn between any two points. In the physics of mind, or of matter, we are far from allowing this. We prefer to it almost any curve that is presented to us by others, – and, without all doubt, any curve which we have described ourselves; and we boldly maintain, and, which is yet more fairly believe, that we have found out a shorter road, merely because, in our philosophical peregrination, we have chosen to journey many miles about, and in our delight of gazing on new objects, have never thought of measuring the ground which we have trod.

I am aware, indeed, that, in the consideration of the simple antecedents, and consequents which nature exhibits, it is not the mere complication of these, by the introduction of new intervening substances or events, which obtains from the mind so ready an adoption of hypotheses. On the contrary, there is a sort of false simplification in the introduction of hypotheses, which itself aids the illusion of the mystery. I term the simplification false, because it is not in the phenomena themselves, but in our mode of conceiving them. It is certainly far more simple, in nature, that bodies should have a tendency toward each other, than that there should be oceans of a subtle fluid, circulating around them, in vortices, – or streams of such a fluid, projected continually on them from some unknown source, merely to produce the same exact motions, which would be the result of the reciprocal tendency in the bodies themselves. But the interposition of all this immensity of matter, to account for the fall of a feather or rain-drop, cumbrous as the contrivance must be allowed to be, is yet in one respect, more simple to our conception, because, instead of two classes of phenomena, those of gravitation and of impulse, we have, in referring all to impulse, only one general class. Man loves what is simple much, but he loves what is mysterious more; and a mighty ocean of ether, operating invisibly in all the visible phenomena of the universe, has thus a sort of double charm, by uniting the false simplification, of which I have spoken, with abundance of real mystery. This mixture of the simple and the mysterious, is, in some measure, like the mixture of uniformity with diversity, that is so delightful in works of art. However pleasing objects may separately be, we are soon wearied with wandering over them, when, from their extreme irregularity, we cannot group them in any distinct assemblage, or discover some slight relation of parts to the whole; and we are still sooner, and more painfully fatigued, when every object which we see is in exact symmetry with some other object. In like manner, the mind would be perplexed and oppressed, if it were to conceive a great multitude of objects or circumstances, concurring in the production of one observed event. But it feels a sort of dissatisfaction also, when the sequences of events which it observes, are reduced to the mere antecedents and consequents of which they consist, and must have a little more complication to flatter it with the belief, that it has learned something which it is important to have learned. To know that a withered leaf falls to the ground, is to know, what the very vulgar know, as well as ourselves; but an ocean of ether, whirling it downward, is something of which the vulgar have no conception, and gives a kind of mysterious magnificence to a very simple event, which makes us think, that our knowledge is greater, because we have given, in our imagination, a sort of cumbrous magnitude to the phenomenon itself.

That hypotheses, in that wide sense of the word which implies every thing conjectural, are without use in philosophy, it would be absurd to affirm, since every inquiry may, in that wide sense, be said to pre-suppose them, and must always pre-suppose them if the inquiry have any object. They are of use, however, not as superseding investigation, but as directing investigation to certain objects, – not as telling us, what we are to believe, but as pointing out to us what we are to endeavour to ascertain. An hypothesis, in this view of it, is nothing more than a reason for making one experiment or observation rather than another; and it is evident, that, without some reason of this kind, as experiment and observations are almost infinite, inquiry would be altogether profitless. To make experiments, at random, is not to philosophize; it becomes philosophy, only when the experiments are made with a certain view; and to make them, with any particular view, is to suppose the presence of something, the operation of which they will tend either to prove or disprove. When Torricelli, for example, – proceeding on the observation previously made, by Galileo, with respect to the limited height to which water could be made to rise in a pump, – that memorable observation, which demonstrated, at last, after so many ages of errors, what ought not for a single moment to have required to be demonstrated; the absurdity of the horror of a void ascribed to nature – when, proceeding in this memorable observation, Torricelli made his equally memorable experiment with respect to the height of the column of mercury supported in an inverted tube, and found, on comparison of their specific gravities, the columns of mercury and water to be exactly equiponderant, it is evident that he was led to the experiment with the mercury by the supposition, that the rise of fluids in vacuo was occasioned by some counterpressure, exactly equal to the weight supported, and that the column of mercury, therefore should be less in height than the column of water, in the exact inverse ratio of their specific gravities, by which the counterpressure was to be sustained. To conceive the air, which was then universally regarded as essentially light, to be not light but heavy, so as to press on the fluid beneath, was, at that time, to make as bold a supposition as could be made. It was indeed, a temporary hypothesis, even when it led to that experimental demonstration of the fact, which proved it forever after not to be hypothetical.

An hypothesis, then, in the first stage of inquiry, far from being inconsistent with sound philosophy, may be said to be essential to it. But it is essential only in this first stage, as suggesting what is afterwards to be verified or disproved; and, when the experiments or observations to which it directs us do not verify it, it is no longer to be entertained, even as an hypothesis. If we observe a phenomenon, which we never have observed before, it is absolutely impossible for us, not to think of the analogous cases which we may have seen; since they are suggested by a principal of association, which is as truly a part of our constitution, as the senses with which we perceived the phenomenon itself; and, if any of these analogies strike us as remarkably coincident, it is equally impossible for us not to imagine, that the cause, which we knew in that former instance, may also be present in this analogical instance, and that they may, therefore, both be reduced to the same class. To stop here, and, from this mere analogy, to infer positive identity of the causes, and to follow out the possible consequences in innumerable applications, would be to do, as many great artists in systematizing have done. What a philosopher, of sounder views, however, would do in such a case, is very different. He would assume, indeed, as possible or perhaps as probable, the existence of the supposed cause. But he would assume it, only to direct his examination of its reality, by investigating, as far as he was able, from past experience, what the circumstances would have been, in every respect, if the cause supposed had been actually present; and, even if these were all found to be exactly coincident, though he would think the presence of the cause more probable, he would be very far from considering it as certain, and would still endeavour to lessen the chances of fallacy, by watching the circumstances, should they again recur, and varying them, by experiment, in every possible way.

This patience and caution, however, essential as they are to just philosophizing, require, it must be confessed, no slight efforts of self-denial, but of a self-denial which is as necessary to intellectual excellence as the various moral species of self-denial are to excellence and virtue.

“Mr Locke, I think,” says Dr Reid, “mentions an eminent musician, who believed that God created the world in six days, and rested the seventh, because there are but seven notes in music. I myself,” he continues, “knew one of that profession, who thought that there could be only three parts in harmony, to wit, bass, tenor, and treble; because there are but three persons in the Trinity.”[30 - On the Powers of the Human Mind, Essay vi. Chap. viii. Vol. II. p. 334. 8vo. edit.]

The minds that could be satisfied with analogies so very slight, must, indeed, have been little acquainted with the principles of philosophic inquiry; and yet how many systems have been advanced in different ages, admired by multitudes, who knew them only by name, and still more revered by the philosophers, who gloried in adopting them, that have been founded on analogies almost as slight.

“The philosophers who form hypothetical systems of the universe, and of all its most secret laws,” says Voltaire, in one of his lively similes, “are like our travellers that go to Constantinople, and think that they must tell us a great deal about the seraglio. They pretend to know every thing which passes within it – the whole secret history of the Sultan and his favourites, and they have seen nothing but its outside walls.”

In one respect, however, philosophers, in their hypothetical systems, far outdo the travellers to Constantinople. They not merely tell us secrets of nature, which they have no opportunity of learning, but they believe the very tales of their own fancy. To see any usual phenomenon, is, indeed, to wonder at it, at first; but to explain it, is almost the very next step, reason serving rather to defend the explanation, when it is made, than to assist greatly in making it; and, in many cases, each philosopher has his separate explanation, on which he is disposed to put as much reliance, as on the certainty of the fact itself, not abandoning the hypothesis, even though the fact should prove to have been different, but making it bend, with a happy pliability, to all the diversities discovered, so as at last, perhaps, to account for circumstances the very reverse of those which it was originally invented to explain. “I have heard,” says Condillac, “of a philosopher, who had the happiness of thinking that he had discovered a principle, which was to explain all the wonderful phenomena of chemistry; and who, in the ardour of his self-congratulation, hastened to communicate his discovery to a skilful chemist. The chemist had the kindness to listen to him, and then calmly told him, that there was but one unfortunate circumstance for his discovery, which was, that the chemical facts were exactly the reverse of what he had supposed. Well then, said the philosopher, have the goodness to tell me what they are, that I may explain them by my system.”[31 - Traite des Systemes, chap. xii. Vol. II. p. 372.] To those who know that fondness for conjecture, which may almost be said to be a sort of intellectual appetite, there is nothing in all the wonders which Swift tells us of his fabled Houynhnhms, that marks them more strongly as a different race from mankind, than the total absence of hypothesis from their systems of knowledge.

“I remember,” says Gulliver, “it was with extreme difficulty that I could bring my master to understand the meaning of the word opinion, or how a point could be disputable; because reason taught us to affirm or deny only when we are certain; and beyond our knowledge we cannot do either. So that controversies, wranglings, disputes, and positiveness, in false or dubious propositions, are evils unknown among the Houynhnhms. In the like manner, when I used to explain to him our several systems of Natural Philosophy, he would laugh, that a creature pretending to reason, should value itself upon the knowledge of other people's conjectures, and in things, where that knowledge, if it were certain, could be of no use. Wherein he agreed entirely with the sentiments of Socrates, as Plato delivers them, which I mention as the highest honour I can do that Prince of philosophers. I have often since reflected what destruction such a doctrine would make in the libraries of Europe, and how many paths to fame would be then shut up in the learned world.”[32 - Travels, Part iv, chap. 8. Swift's Works, edit. Nichols, Vol. ix. p. 300.]

While I wish to caution you against a fondness for hypotheses, by shewing you, not merely that they are liable to error, – for inquiry, of every kind, must be so in some degree, – but that, in truth, they leave the real difficulty of the succession of the observed consequents to the observed antecedents as great as before, and only add, to the supposed difficulty of explaining one sequence, the necessity of explaining a sequence additional, – I must remark, at the same time, that what is commonly termed theory, in opposition to hypothesis, is far from being so different from it as is commonly represented, – at least, in the very wide application which is usually made of it. We are told, by those who lay down rules of philosophizing, that the object of philosophy is, to observe particulars, and, from these, to frame general laws, which may, again, be applied to the explanation of particulars; and the view which is thus given of the real province of philosophy is undoubtedly a just one; – but there is an ambiguity in the language which may deceive you, and with respect to which, therefore, it is necessary for you to be on your guard. If, by the term general law, be meant the agreement in some common circumstances of a number of events observed, there can be no question that we proceed safely in framing it, and that what we have already found in a number of events, must be applicable to that number of events; in the same manner, as, after combining in the term animal the circumstances in which a dog, a horse, a sheep agree, we cannot err in applying the term animal to a dog, a horse, a sheep. But the only particular to which, in this case, we can, with perfect confidence, apply a general law, are the very particulars that have been before observed by us. If it be understood as more general than the circumstances observed, and, therefore, capable of being applied with perfect certainty to the explanation of new phenomena, we evidently, to the extent in which the general law is applied beyond the circumstances observed, proceed on mere supposition, as truly, as in any hypothesis which we could have framed; and though the supposition may be more and more certain, in proportion to the number of cases thus generalized, and the absence of any circumstance which can be supposed, in the new case, to be inconsistent with it, it never can amount to actual certainty. Let us take, for example, one of the most striking cases of this sort. That bodies tend to each other, in all circumstances, with a force increasing directly as their quantities, and inversely as the squares of their distances, may seem in the highest degree probable indeed, from the innumerable facts observed on our globe, and in the magnificent extent of the planetary movements; but it cannot be said to be certain at all distances, in which we have never had an opportunity of making observations, – as it seems to be verified in the heights of our atmosphere, and in the distances of the planets, in their orbits, from the sun, and from each other. It is not necessary, however, to refer, for possible exceptions, to spaces that are beyond our observation; since, on the surface of our own earth, there is abundant evidence, that the law does not hold universally. Every quiescent mass that is capable of greater compression, and of which the particles, therefore, before that compression, are not in absolute contact, shews sufficiently, that the principle of attraction, which, of itself, would have brought them into actual contact, must have ceased to operate, while there was still a space between the particles that would have allowed its free operation; and, in the phenomena of elasticity, and impulse in general, it has not merely ceased, but is actually reversed, – the bodies which, at all visible distances, exhibited a reciprocal attraction, now exhibiting a reciprocal repulsion, in consequence of which they mutually fly off, as readily as they before approached, – that is to say, the tendency of bodies to each other being converted into a tendency from each other, by a mere change of distance, so slight as to be almost inappreciable. When a ball rebounds from the earth, toward which it moved rapidly before, and the gravitating tendency is thus evidently reversed, without the intervention of any foreign force, what eye, though it be aided by all the nicest apparatus of optical art, can discover the lines which separate those infinitesimal differences of proximity, at which the particles of the ball still continue to gravitate toward the earth, and are afterwards driven from it in an opposite direction; – yet the phenomenon itself is a sufficient proof, that in these spaces, which seem, to our organs of sense, so completely the same, that it is absolutely impossible for us to distinguish them, the reciprocal tendencies of the particles of the ball and of the earth are as truly opposite, as if the laws of gravitation had, at the moment at which the rebound begins, been reversed through the whole system of the universe.

It is, indeed, scarcely possible to imagine a more striking proof of the danger of extending, with too great certainty, a general law, than this instant conversion of attraction into repulsion, without the addition of any new bodies, without any change in the nature of the bodies themselves, and a change of their circumstances so very slight, as to be absolutely indistinguishable, but for the opposite motions that result from it, with a change of their circumstances. After observing the gravity of bodies, at all heights of our atmosphere, and extending our survey through the wide spaces of our solar system, – computing the tendency of the planets to the sun, and their disturbing forces, as they operate on each other, – and finding the resulting motions exactly to correspond with those which we had predicted by theory; – in these circumstances, after an examination so extensive, if we had affirmed, as an universal law of matter, that, at all distances, bodies tend toward each other, we should have considered the wideness of the induction, as justifying the affirmation; and yet, even in this case, we find, on the surface of our earth, in the mutual shocks of bodies, and in their very rest, sufficient evidence, that, in making the universal affirmation, we should have reasoned falsely. There is no theory, then, which, if applied to the explanation of new phenomena, is not, to a certain degree, conjectural; because it must proceed on the supposition, that what was true in certain circumstances, is true also in circumstances that have not been observed. It admits of certainty, only when it is applied to the very substances observed, – in the very circumstances observed, – in which case, it may be strictly said to be nothing more than the application of a general term to the particulars, which we have before agreed to comprehend in it. Whatever is more than this is truly hypothetical, – the difference being, that we commonly give the name of hypothesis to cases, in which we suppose the intervention of some substance, of the existence of which, as present in the phenomenon, we have no direct proof, or of some additional quality of a substance before unobserved, – and the name of theory to cases, which do not suppose the existence of any substance, that is not actually observed, or of any quality that has not been actually observed, but merely the continuance, in certain new circumstances, of tendencies observed in other circumstances. Thus, if a planet were discovered revolving in the space which separates the orbits of any two planets at present known, were we to suppose of matter, in this new situation, that it would be subject to the same exact law of gravitation, to which the other planets were known to be subject, and to predict its place in the heavens, at any time, according to this law, we should be said to form a theory of its motions; as we should not take for granted, any new quality of a substance, or the existence of any substance, which was not evidently present, but only of tendencies observed before in other circumstances, – analogous indeed, but not absolutely the same. We should be said to form an hypothesis on the subject, if, making the same prediction, as to its motions, and place in the heavens, at any given time, we were to ascribe the centripetal tendency, which confines it within its orbit, to the impulse of ether, or to any other mechanical cause. The terms, however, I must confess, though the distinction which I have now stated would be, in all cases, a very convenient one, are used very loosely, not in conversation merely, but in the writings of philosophers, – an hypothesis often meaning nothing more than a theory, to which we have not given our assent, – and a theory, an hypothesis which we have adopted, or still more, one which we have formed ourselves.