ciples of that science of which I am to treat: and who are anxious to remove the prejudices which have, in a great measure, excluded it from the modern systems of education. In the progress of work, I flatter myself that I shall not often have occasion to solicit the indulgence of my readers, for an unnecessary diffuseness.

my

The notion we annex to the words, matter and mind, as is well remarked by Dr. Reid, (in his Essays on the Active Powers of Man,) are merely relative. If I am asked, what I mean by matter? I can only explain myself by saying, it is that which is extended, figured, colored, movable, hard or soft, rough or smooth, hot or cold; that is, I can define it in no other way than by enumerating its sensible qualities. It is not matter, or It is not matter, or body, which I perceive by my senses; but only extension, figure, color, and certain other qualities, which the constitution of my nature leads me to refer to something, which is extended, figured, and colored. The case is precisely similar with respect to mind. We are not immediately conscious of its existence, but we are conscious of sensation, thought, and volition; operations, which imply the existence of something which feels, thinks, and wills. Every man, too, is impressed with an irresistible conviction, that all these sensations, thoughts, and volitions, belong to one and the same being; to that being, which he calls himself; a being, which he is led, by the constitution of his nature, to consider as something distinct from his body, and as not liable to be impaired by the loss or mutilation of any of his organs.

From these considerations, it appears, that we have the same evidence for the existence of mind, that we have for the existence of body; nay, if there be any difference between the two cases, that we have stronger evidence for it; inasmuch as the one is suggested to us by the subjects of our own consciousness, and the other merely by the objects of our perceptions: and in this light, undoubtedly, the fact would appear to every person, were it not, that, from our earliest years, the attention is engrossed with the qualities and laws of matter, an acquaintance with which is absolutely necessary for the preservation of our animal existence. Hence it is, that these phenomena occupy our thoughts more than those of mind; that we are perpetually tempted to explain the latter by the analogy of the former, and even to endeavor to refer them to the same general laws; and that we acquire habits of inattention to the 'subjects of our consciousness, too strong to be afterwards surmounted, without the most persevering industry.

If the foregoing observations be well founded, they establish the distinction between mind and matter, without any long process of metaphysical reasoning: for if our notions of both are merely

* I am happy in being able to quote the following passage, in illustration of a doctrine, against which I do not conceive it possible to urge any thing, but the authority of some illustrious names.

"Puisque l'existence des corps n'est pour nous que la permanence d'êtres dont

relative; if we know the one, only by such sensible qualities as extension, figure, and solidity; and the other, by such operations as sensation, 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 the phenomena exhibited to our senses; that of the latter, on the phenomena of which we are conscious. Instead, therefore, of objecting to the scheme of materialism, that its conclusions are les propriétés répondent à un certain ordre de nos sensations, il en résulte qu'elle n'a rien de plus certain que celle d'autres êtres qui se manifestent également par leurs effets sur nous; et puisque nos observations sur nos propres facultés, confirmées par celles que nous faisons sur les êtres pensants qui animent aussi des corps, ne nous montrent aucune analogie entre l'être qui sent ou qui pense et l'être qui nous offre le phénomène de l'étendue ou de l'impénétrabilité, il n'y a aucune raison de croire ces êtres de la même nature. Ainsi la spiritualité de l'ame n'est pas une opinion qui ait besoin de preuves, mais le résultat simple et naturel d'une analyse exacte de nos idées, et de nos facultés."-Vie de M. Turgot, par M. Condorcet.

Des Cartes was the first philosopher who stated, in a clear and satisfactory manner, the distinction between mind and matter, and who pointed out the proper plan for studying the intellectual phenomena. It is chiefly in consequence of his precise ideas with respect to this distinction, that we may remark, in all his metaphysical writings, a perspicuity which is not observable in those of any of his predecessors.

Dr. Reid has remarked, that although Des Cartes infers the existence of mind, from the operations of which we are conscious, yet he could not reconcile himself to the notion of an unknown substance, or substratum, to which these operations belonged. And it was on this account, he conjectures, that he made the essence of the soul to consist in thought; as, for a similar reason, he had made the essence of matter to consist in extension. But I am afraid, that this supposition is not perfectly reconcilable with Des Cartes' writings; for he repeatedly speaks with the utmost confidence of the existence of substances of which we have only a relative idea; and, even ih attempting to show that thought is the essential attribute of mind, and extension of matter, he considers them as nothing more than attributes or qualities belonging to these substances.

Per substantium nibil aliud intelligere possumus, quam rem quæ ita existit, ut nulla alia re indigeat ad existendum. Et quidem substantia quæ nulla plane nisi ope concursus Dei existere posse percipimus. At que ideo nomen substantiæ non convenit Deo et illis univoce ut dici solet in scholis; hoc est, nulla ejus nominis significatio, potest distincte intelligi, quæ Deo, et creaturis sit communis. "Possunt autem substantia corporea, et mens, sive substantia cogitans, creata, sub hoc communi conceptu intelligi; quod sint res, quæ solo Dei concursu egent ad existendum. Verumtamen non potest substantia primum animadverti ex hoc solo, quod sit res existens, quia hoc solum per se nos non afficit: sed facile ipsam agnoscimus ex quodlibet ejus attributo, per communem illam notionem, quod nihili nulla sunt attributa, nullæve proprietates aut qualitates. Ex hoc enim, quod aliquod attributum adesse percipiamus, concludimus aliquam rem existentem, sive substantiam cui illud tribui possit, necessario etiam adesse.

"Et quidem ex quolibet attributo substantia cognoscitur: sed una tamen est cujusque substantiæ præcipua proprietas, quæ ipsius naturam essentiamque constituit, et ad quam aliæ omnes referuntur. Nempe extentio in longum, latum et profundum substantiæ corporeæ naturum constituit; et cogitatio constituit naturam substantiæ cogitantis."-Princip. Philosoph. pars i. cap. 51-53.

In stating the relative notions which we have of mind and of body, I have avoided the use of the word substance, as I am unwilling to furnish the slightest occasion for controversy; and have contented myself with defining mind to be that which feels, thinks, wills, hopes, fears, desires, &c. That my consciousness of these and other operations is necessarily accompanied with a conviction of my own existence, and with a conviction that all of them belong to one and the same being, is not an hypothesis, but a fact; of which it is no more possible for me to doubt, than of the reality of my own sensations or volitions.

false, it would be more accurate to say, that its aim is unphilosophical. It proceeds on a misapprehension of the proper object of science; the difficulty which it professes to remove 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 and attributes alone, and that we are totally ignorant of the essence of either.*

As all our knowledge of the material world is derived from the information of our senses, natural philosophers have, in modern times, wisely abandoned to metaphysicians, all speculations concerning the nature of that substance of which it is composed; concerning the possibility or impossibility of its being created; concerning the efficient causes of the changes which take place in it; and even concerning the reality of its existence, independent of that of percipient beings: and have confined themselves to the hnmbler province of observing the phenomena it exhibits, and of ascertaining their general laws. By pursuing this plan steadily, they have, in the course of the two last centuries, formed a body of science, which not only does honor to the human understanding, but has had a most important influence on the practical arts of life. This experimental philosophy, no one now is in danger of confounding with the metaphysical speculations already mentioned. Of the importance of these, as a separate branch of study, it is possible that some may think more favorably than others; but they are obviously different in their nature, from the investigations of physics; and it is of the utmost consequence to the evidence of this last science, that its principles should not be blended with those of the former.

A similar distinction takes place among the questions which may be stated relative to the human mind.-Whether it be extended or unextended; whether or not it has any relation to place; and (if it has) whether it resides in the brain, or be spread over the body, by diffusion; are questions perfectly analogous to those which metaphysicians have started on the subject of matter. It is unnecessary to inquire, at present, whether or not they admit of answer. is sufficient for my purpose to remark, that they are as widely and obviously different from the view, which I propose to take, of the human mind in the following work, as the reveries of Berkeley concerning the non-existence of the material world, are from the

It

* Some metaphysicians, who appear to admit the truth of the foregoing reasoning, have farther urged, that for any thing we can prove to the contrary, it is possible, that the unknown substance which has the qualities of extension, figure, and color, may be the same with the unknown substance which has the attributes of feeling, thinking, and willing. But besides that this is only an hypothesis, which amounts to nothing more than a mere possibility, even if it were true, it would no more be proper to say of mind, that it is material, than to say of body, that it is spiritual.

conclusions of Newton, and his followers. It is farther evident, that the metaphysical opinions, which we may happen to have formed concerning the nature either of body or of mind, and the efficient causes by which their phenomena are produced, have no necessary connexion with our inquiries concerning the laws, according to which these phenomena take place. Whether (for example) the cause of gravitation be material or immaterial, is a point about which two Newtonians may differ, while they agree perfectly in their physical opinions. It is sufficient, if both admit the general fact, that bodies tend to approach each other, with a force varying with their mutual distance, according to a certain law. In like manner, in the study of the human mind, the conclusions to which we are led, by a careful examination of the phenomena it exhibits, have no necessary connexion with our opinions concerning its nature and essence. That when two subjects of thought, for instance, have been repeatedly presented to the mind in conjunction, the one has a tendency to suggest the other, is a fact of which I can no more doubt, than of any thing for which I have the evidence of my senses; and it is plainly a fact totally unconnected with any hypothesis concerning the nature of the soul, and which will be as readily admitted by the materialist as by the Berkeleian.

Notwithstanding, however, the reality and importance of this distinction, it has not hitherto been sufficiently attended to by the philosophers who have treated of the human mind. Dr. Reid is perhaps the only one who has perceived it clearly, or at least who has kept it steadily in view, in all his inquiries. In the writings, indeed, of several other modern metaphysicians, we meet with a variety of important and well-ascertained facts; but, in general, these facts are blended with speculations upon subjects which are placed beyond the reach of the human faculties. It is this mixture of fact, and of hypothesis, which has brought the philosophy of mind into some degree of discredit; nor will ever its real value be generally acknowledged, till the distinction I have endeavored to illustrate, be understood, and attended to, by those who speculate on the subject. By confining their attention to the sensible qualities of body, and to the sensible phenomena it exhibits, we know what discoveries natural philosophers have made and if the labors of metaphysicians shall ever be rewarded with similar success, it can only be, by attentive and patient reflection on the subjects of their own consciousness.

I cannot help taking this opportunity of remarking, on the other hand, that if physical inquirers should think of again employing themselves in speculations about the nature of matter, instead of attempting to ascertain its sensible properties and laws, (and of late there seems to be such a tendency among some of the followers of Boscovich,) they will soon involve themselves in an inextricable labyrinth, and the first principles of physics will be rendered as mysterious and chimerical as the pneumatology of the schoolmen.

2

The little progress which has hitherto been made in the philosophy of mind, will not appear surprising to those who have attended to the history of natural knowledge. It is only since the time of Lord Bacon, that the study of it has been prosecuted with any degree of success, or that the proper method of conducting it has been generally understood. There is even some reason for doubting, from the crude speculations on medical and chemical subjects which are daily offered to the public, whether it be yet understood so completely as is commonly imagined; and whether a fuller illustration of the rules of philosophizing, than Bacon or his followers have given, might not be useful, even to physical inquirers. When we reflect, in this manner, on the shortness of the period during which natural philosophy has been successfully cultivated; and, at the same time, consider how open to our examination the laws of matter are, in comparison of those which regulate the phenomena of thought, we shall neither be disposed to wonder, that the philosophy of mind should still remain in its infancy, nor be discouraged in our hopes concerning its future progress. The excellent models of this species of investigation, which the writings of Dr. Reid exhibit, give us ground to expect that the time is not far distant, when it shall assume that rank which it is entitled to hold among the sciences.

It would probably contribute much to accelerate the progress of the philosophy of mind, if a distinct explanation were given of its nature and object; and if some general rules were laid down, with respect to the proper method of conducting the study of it. To this subject, however, which is of sufficient extent to furnish matter for a separate work, I cannot attempt to do justice at present; and shall therefore confine myself to the illustration of a few fundamental principles, which it will be of essential importance for us to keep in view in the following inquiries.

Upon a slight attention to the operations of our minds, they appear to be so complicated, and so infinitely diversified, that it seems to be impossible to reduce them to any general laws. In consequence, however, of a more accurate examination, the prospect clears up; and the phenomena, which appeared, at first, to be too various for our comprehension, are found to be the result of a comparatively small number of simple and uncompounded faculties, or of simple and uncompounded principles of action. These faculties and principles are the general laws of our constitution, and hold the same place in the philosophy of mind, that the general laws we investigate in physics, hold in that branch of science. both cases, the laws which nature has established, are to be investigated only by an examination of facts; and in both cases, a knowledge of these laws leads to an explanation of an infinite number of phenomena.

In

In the investigation of physical laws, it is well known that our inquiries must always terminate in some general fact, of which no