The absurdity of such inquiries, into any thing more than the mere phenomena, if it be not sufficiently evident of itself, may, perhaps, be rendered more apparent, by a very easy supposition. Let us imagine the permanent unknown substance matter, and the permanent unknown substance mind, to be rendered, by the same divine power which made them, altogether different in their own absolute essence, as they exist independently, but to exhibit relatively, precisely the same phenomena as at present,—that spring, and summer, and autumn, and winter, in every appearance that can affect our organs of perception, succeed each other as now, pouring out the same profusion of foliage, and flowers, and fruits, and, after the last gladness of the vintage and the harvest, sweeping the few lingering blossoms, with those desolating blasts, which seem like the very destroyers of nature, while they are only leading in, with great freshness, under the same benevolent eye of Heaven, the same delightful circle of beauty and abundance,—that, in mind, the same sensations are excited by the same objects, and are followed by the same remembrances, and comparisons, and hopes, and fears;—in these circumstances, while all the phenomena which we observe, and all the phenomena of which we are conscious, continue exactly the same, can we believe, that we should be able to discover the essential change, which, according to this supposition, had taken place, in the permanent subjects of these unvaried phenomena! And, if, as long as the external and internal phenomena continued exactly the same, we should be incapable of discovering, or even suspecting, the slightest change, where, by supposition, there had been a change so great, how absurd is it to conceive that the changed or unchanged nature of the substance itself, as it exists independently of the phenomenon, ever can become known to us.
He, indeed, it may always safely be presumed, knows least of the mind, who thinks that he knows its substance best. “What is the soul?” was a question once put to Marivaux. “I know nothing of it,” he answered, “but that it is spiritual and immortal.” “Well,” said his friend, “let us ask Fontenelle, and he will tell us what it is.” “No,” cried Marivaux, “ask any body but Fontenelle, for he has too much good sense to know any more about it than we do.”
It is to the phenomena only, then, that our attention is to be given, not to any vain inquiries into the absolute nature of the substances which exhibit the phenomena. This alone is legitimate philosophy,—philosophy which must forever retain its claim to our assent, amid the rise and fall of all those spurious speculations, to which our vanity is so fond of giving the names of theory and system. Whatever that may be, in itself, which feels, and thinks, and wills,—if our feelings, and thoughts, and volitions be the same—all which we can know, and compare, and arrange, must be the same; and, while we confine our attention to these, the general laws of their succession which we infer, and the various relations which they seem to bear to each other, may be admitted equally by those whose opinions, as to the absolute nature of the feeling and thinking principle, differ fundamentally. It requires no peculiar supposition, or belief, as to the nature of the mind, to know, that its trains of thought are influenced, by former habits, or casual association; and every fact, which the immaterialist has accurately observed and arranged, with respect to the influence of habit or association, may thus, with equal reason, form a part of the intellectual and moral creed of the materialist also.
On these two systems it is not at present my intention to make any remarks; all which I wish, now, is to explain to you, how independent the real philosophy of the mind is, of any fanciful conjectures, which may be formed, with respect to its essence. It differs from these, as Mr. Stewart has well observed, in the same manner “as the inquiries of Galileo, concerning the laws of moving bodies, differ from the disputes of the ancient Sophists, concerning the existence and the nature of motion,” or as the conclusions of Newton, with respect to the law of gravitation, differ from his query concerning the mode in which he supposed that gravity might possibly be produced. The hypothesis, involved in the query, you may admit or reject; the conclusions, with respect to the law of gravitation itself, as far as relates to our planetary system, are, I may say, almost beyond your power of rejecting.
The philosophy of mind then, and the philosophy of matter, agree, in this respect, that our knowledge is, in both, confined to the mere phenomena. They agree also, in the two species of inquiry which they admit. The phenomena of mind, in the same manner as we have seen in the case of matter, may be considered as complex and susceptible of analysis, or they may be considered as successive in a certain order, and bearing, therefore, to each other the reciprocal relation of causes and effects.
That we can know the phenomena, only as far as we have attended to their sequences, and that, without experiment, therefore, it would have been impossible for us to predict any of their successions, is equally true, in mind as in matter. Many of the successions, indeed, are so familiar to us, that it may appear to you, at first, very difficult to conceive, that we should not have been able, at least with respect to them, to predict, originally, what antecedents would have been followed by what consequents. We may allow certainly, that we should not have been able to foresee the pleasure which we receive from the finer works of imitative art—from the successions, or co-existences, in music, of sounds, that, considered separately, would scarcely be counted among the sources of delight—from the charm of versification, that depends on circumstances, so very slight, as to be altogether destroyed, and even converted into pain, by the change of quantity of a single syllable. But, that the remembrance of pleasure should not be attended with desire of enjoying it again, seems to us almost inconsistent with the very nature of the pleasing emotion. In like manner, we may allow, that we could not have predicted the sympathy which we feel with the distresses of others, when they arise from causes that cannot affect us, and yet make, for the time, the agony, which we merely behold, a part of our own existence. But we can scarcely think, that we require any experience, to know, that the contemplation of pain, which we may ourselves have to endure, should be the cause of that painful feeling, to which we give the name of fear, or that the actual suffering should be accompanied with the desire of relief. The truth is, however, that, in all these cases, and in all of them equally,—it would have been impossible, but for experience, to predict the consequent of any of the antecedents. The pleasure, which we feel, in the contemplation of a work of art, the pain, which we feel, at the sight of the misery of others, are as much the natural effects of states of mind preceding them, as the fear of pain is the effect of the consideration of pain as hanging over us. Our various feelings, similar or dissimilar, kindred or discordant, are all mere states of the mind; and there is nothing, in any one state of the mind, considered in itself, which, necessarily, involves the succession of any other state of mind. That particular state, for example, which constitutes the mere feeling of pain, instead of being attended by that different state which constitutes the desire of being freed from pain, might have continued, as one uniform feeling, or might have ceased, and been succeeded by some other state, though in the original adaptation of our mental frames, by that Creator's wisdom which planned the sequences of its phenomena, the particular affection, which constitutes desire, had not been one of the innumerable varieties of affection, of which the mind was forever to be susceptible.
What susceptibilities the mind has exhibited in the ordinary circumstances in which it has been placed, we know, and they have been limited to a certain number, corresponding with the feelings which have arisen in these circumstances. But the Almighty Power, who fixed this particular number, might have increased or lessened the number at His pleasure, in the same manner, as He might, at His pleasure, have multiplied or diminished the whole number of his animated creatures; and, where there has been no limit, but the will of the Limiter, it is experience only which can give us any knowledge of the actual limitation. We are always too much inclined to believe, that we know what must have been, because we know what is,—and to suppose ourselves acquainted, not merely with the gracious ends which Supreme Goodness had in view, in creating us, but with the very object, which each separate modification of our intellectual and moral constitution was intended to answer. I would not, indeed, go so far as Pope, in that passage of the Essay on Man, in which he seems to imply, that our ignorance of the wise and harmonious intentions of Providence, in the constitution of our mind, is like the ignorance of the inferior animals, as to the motives which influence the follies and inconsistencies of their capricious master.
“When the proud steed shall know, why man restrains
His fiery course, or drives him o'er the plains,