PRELIMINARY DISSERTATION. CHAPTER FIRST. THE chief aim of the following dissertation is, to correct some prevailing mistakes with respect to the Philosophy of the Human Mind. In the introduction to a former Work, I have enlarged, at considerable length, upon the same subject; but various publications which have since appeared, incline me to think, that, in resuming it here, I undertake a task not altogether superfluous. Of the remarks which I am now to state, a few have a particular reference to the contents of this volume. Others are intended to clear the way for a different series of discussions, which I hope to be able, at some future period to present to the public. I. In the course of those speculations on the Mind, to which I have already referred, and with which, I trust, that my present readers are not altogether unacquainted, I have repeatedly had occasion to observe, that "as our notions both of matter and of mind are merely relative; as we know the one only by such sensible qualities as extension, figure, and solidity, and the other by such operations as sensations, thought, and volition; we are certainly entitled to say, that matter and mind, considered as Objects of Human Study, are essentially different; the science of the former resting ultimately on phenomena exhibited to our senses, that of the latter on phenomena of which we are conscious. Instead, therefore, of objecting to the scheme of materialism, that its conclusions are false, it would be more accurate to say, that its aim is unphilosophical. It proceeds on a misapprehension of the extent and the limits of genuine science; the difficulty, which it professes to remov being manifestly placed beyond the reach of our faculties. Surely, when we attempt to explain the nature of that principle, which feels, and thinks, and wills, by saying, that it is a material substance, or that it is the result of material organization, we impose on ourselves by words; forgetting that matter, as well as mind, is known to us by its qualities alone, and that we are equally ignorant of the essence of either." In the farther prosecution of the same argument, I have attempted to show, that the legitimate province of this department of philosophy extends no farther than to conclusions resting on the solid basis of observation and experiment; and I have, accordingly, in my own inquiries, aimed at nothing more, than to ascertain, in the first place, the Laws of our Constitution, as far as they can be discovered by attention to the subjects of our consciousness; and afterwards to apply these laws as principles for the synthetical explanation of the more complicated phenomena of the understanding. It is on this plan I have treated of the association of ideas, of memory, of imagination, and of various other intellectual powers; imitating, as far as I was able, in my reasonings, the example of those who are allowed to have cultivated the study of Natural Philosophy with the greatest success. The Physiological Theories which profess to explain how our different mental operations are produced by means of vibrations, and other changes in the state of the sensorium, if they are not altogether hypothetical and visionary, cannot be considered, even by their warmest advocates, as resting on the same evidence with those conclusions which are open to the examination of all men capable of exercising the power of Reflection; and, therefore, scientific distinctness requires, that these two different classes of propositions should not be confounded together under one common name. For my own part, I have no scruple to say, that I consider the physiological problem in question, as one of those which are likely to remain for ever among the arcana of nature, nor am I afraid of being contradicted by any competent and candid judge, how sanguine soever may be his hopes concerning the progress of future discovery, when I assert, that it has hitherto eluded completely all the efforts which have been made towards its solution. As to the metaphysical romances above alluded to, they appear to me, after all the support and illustration which they have received from the ingenuity of Hartley, of Priestley, and of Darwin, to be equally unscientific in the design, and uninteresting in the execution; destitute, at once, of the sober charms of Truth, and of those imposing attractions, which Fancy, when united to Taste, can lend to Fiction. In consequence of the unbounded praise which I have heard bestowed upon them, I have repeatedly begun the study of them anew, suspecting that I might be under the influence of some latent and undue prejudice against this new mode of philosophizing, so much in vogue at present in England: but notwithstanding the strong predilection which I have always felt for such pursuits, my labor has uniformly ended in a sentiment of regret, at the time and attention which I had misemployed in so hopeless and so ungrateful a task. Mr. Locke, although he occasionally indulges himself in hints and conjectures, somewhat analogous to those of Hartley and Darwin, seems to have been perfectly aware how foreign such speculations are to the genuine Philosophy of the Human Mind. The following are his own words, in the second paragraph of the Introduction to his Essay:-"This, therefore, being my purpose, to inquire into the original, certainty, and extent of Human knowledge; together with the grounds and degrees of belief, opinion, and assent, I shall not, at present, meddle with the physical consideration of the mind, or trouble myself to examine, wherein its essence consists, or by what motions of our spirits, or alteration of our bodies, we come to have any sensation by our organs, or any ideas of our understandings; and whether these ideas do in their formation, any or all of them, depend on matter or not. These are speculations, which, however curious and entertaining, I shall decline, as lying out of my way in the design I am now upon." It is much to be wished, that Mr. Locke had adhered invariably to this wise resolution. I flatter myself it will not be inferred, from the manner in which I have expressed myself with respect to the common theories of physiologists about the causes of the intellectual phenomena, that I entertain any doubt of the intimate connexion which exists between these phenomena and the organization of the body. The great principle which I am anxious to inculcate, is, that all the theories which have yet been offered on this subject, are entirely unsupported by proof; and what is worse, are of such a kind, that it is neither possible to confirm nor to refute them, by an appeal to experiment or observation. That I was all along fully aware of the dependence, in our present state, of our mental operations on the sound condition of our corporeal frame, appears sufficiently from what I remarked, many years ago, concerning the laws of this connexion between mind and body, as presenting one of the most interesting objects of examination connected with the theory of human nature.* I have been induced to caution my Readers against the possibility of such a misapprehension of my meaning by the following passage in a late publication: "What that affection of the brain is," says Mr. Belsham," which, by the constitution of human nature, causes Memory, we cannot absolutely ascertain. The hypothesis of Vibrations, which has already been explained, is the most probable. It is trifling to object, that if the existence of impressions on the brain could be proved, Memory would remain as unaccountable as before: all which this hypothesis pretends to, is to advance a step in tracing the process of the connexion between external objects and mental feelings,""It is curious to observe," the same author continues, "that Dr. Reid, after starting several objections against the commonly received hypotheses, is obliged to admit, that many well-known facts lead us to conclude, that a certain constitution or state of the brain is necessary to Memory.' On this passage I shall offer only two remarks. The first is, that, notwithstanding Mr. Belsham's zeal for * Philosophy of the Human Mind, vol. i. pp. 11, 12, 3d ed. |