supposed vibrations, or other changes, in the state of the brain; or to explain Memory, by means of supposed impressions and traces in the sensorium; we evidently blend a collection of important and well-ascertained truths, with principles which rest wholly on conjecture.*

The Analogy of Matter no Guide to the Philosophy of Mind. -Beside this inattention to the proper limits of philosophical inquiry, other sources of error, from which the science of physics is entirely exempted, have contributed to retard the progress of the philosophy of mind. Of these, the most important proceed from that disposition which is so natural to every person, at the commencement of his philosophical pursuits, to explain intellectual and moral phenomena by the analogy of the material world.

I before took notice of those habits of inattention to the subjects of our consciousness, which take their rise in that period of our lives when we are necessarily employed in acquiring a knowledge of the properties and laws of matter. In consequence of this early familiarity with the phenomena of the material world, they appear to us less mysterious than those of mind; and we are apt to think that we have advanced one step in explaining the latter, when we can point out some analogy between them and the former. It is owing to the same circumstance, that we have scarcely any appropriated language with

*["When I speak,” says Crousaz, in his Art of Thinking, "of desire, contentment, trouble, apprehension, doubt, certainty, of affirming, denying, approving, blaming, -I pronounce words the meaning of which I distinctly understand; and yet I do not represent the things spoken of under any image or corporeal form. While the intellect, however, is thus busy about its own phenomena, the imagination is also at work in presenting its analogical theories; but so far from aiding us, it only misleads our steps and retards our progress. Would you know what thought is? It is precisely that which passes within you when you think. Stop but here, and you are sufficiently informed. But the imagination, eager to proceed further, would gratify our curiosity by comparing it to fire, to vapor, or to other active and subtile principles in the material world. And to what can all this tend, but to divert our attention from what thought is, and to fix it upon what it is not?"]

respect to mind, and that the words which express its different operations, are almost all borrowed from the objects of our senses.* It must, however, appear manifest, upon a very little reflection, that as the two subjects are essentially distinct, and as each of them has its peculiar laws, the analogies we are pleased to fancy between them, can be of no use in illustrating either; and that it is no less unphilosophical to attempt an explanation of Perception, or of the Association of Ideas, upon mechanical principles; than it would be to explain the phenomena of gravitation, by supposing, as some of the ancients did, the particles of matter to be animated with principles of motion; or to explain the chemical phenomena of elective attractions, by supposing the substances among which they are observed, to be endowed with thought and volition. The analogy of matter, therefore, can be of no use in the inquiries which form the object of the following work; but, on the contrary, is to be guarded against, as one of the principal sources of the errors to which we are liable.

* ["If we critically examine any language, ancient or modern, and trace its several terms or phrases to their source, we shall find it hold invariably, that all the words made use of to denote spiritual and intellectual things, are in their origin metaphors, taken from objects of sense. This shows evidently, that the latter [objects of sense] have made the earliest impressions, have by consequence first obtained names in every tongue, and are still, as it were, more present with us, and strike the imagination more forcibly than the former [spiritual and intellectual things.]

Campbell's Philosophy of Rhetoric, Book III. Chapter i. 3. Numberless instances might be given; but a very few will suffice. Imagination is derived from an optical image; acuteness, from a Latin word signifying the sharpness of a material instrument; reflection, from bending back a ray of light; apprehension originally meant seizure, or taking hold of something by the hand; instil means to drop into; spirit is breath; animal and animation, (anima, ŭveμos) come from breath, and ultimately from wind; melancholy means black bile; faint-hearted and milk-livered have come to mean cowardly, and hard-hearted to mean cruel; understanding, foresight, inclination, penetration, etc., suggest their own etymology.]

PART II.

OF THE UTILITY OF THE PHILOSOPHY OF THE HUMAN MIND.

Connection of the Arts and Sciences with each other. - It has been often remarked, that there is a mutual connection between the different arts and sciences; and that the improvements which are made in one branch of human knowledge, frequently throw light on others, to which it has apparently a very remote relation. The modern discoveries in astronomy and in pure mathematics have contributed to bring the art of navigation to a degree of perfection formerly unknown. The rapid progress which has been lately made in astronomy, anatomy, and botany, has been chiefly owing to the aid which these sciences have received from the art of the optician.

Although, however, the different departments of science and of art mutually reflect light on each other, it is not always necessary either for the philosopher or the artist to aim at the acquisition of general knowledge. Both of them may safely take many principles for granted, without being able to demonstrate their truth. A seaman, though ignorant of mathematics, may apply, with correctness and dexterity, the rules for finding the longitude. An astronomer or a botanist, though ignorant of optics, may avail himself of the use of the telescope or the mi

croscope.

These observations are daily exemplified in the case of the artist; who has seldom either inclination or leisure to speculate concerning the principles of his art. It is rarely, however, we meet with a man of science who has confined his studies wholly to one branch of knowledge. That curiosity, which he has been accustomed to indulge in the course of his favorite pursuit, will naturally extend itself to every remarkable object which falls under his observation, and can scarcely fail to be a source of perpetual dissatisfaction to his mind, till it has been so far gratified as to enable him to explain all the various phenomena

which his professional habits are every day presenting to his view.

All the sciences and all human employments connected with the science of mind. As every particular science is in this manner connected with others, to which it naturally directs the attention, so all the pursuits of life, whether they terminate in speculation or action, are connected with that general science which has the human mind for its object. The powers of the understanding are instruments which all men employ; and his curiosity must be small indeed, who passes through life in total ignorance of faculties which his wants and necessities force him habitually to exercise, and which so remarkably distinguish man from the lower animals.* The phenomena resulting from these

*["'T is evident," says David Hume, "that all the sciences have a relation, greater or less, to human nature, and that, however wide any of them may seem to run from it, they still return back by one passage or another. Even mathematics, natural philosophy, and natural religion, are in some measure dependent on the science of man; since they lie under the cognizance of men, and are judged of by their powers and faculties. It is impossible to tell what changes and improvements we might make in these sciences, were we thoroughly acquainted with the extent and force of human understanding, and could explain the nature of the ideas we employ, and of the operations we perform in our reasonings.

"If, therefore, the sciences of mathematics, natural philosophy, and natural religion, have such a dependence on the knowledge of man, what may be expected in the other sciences, whose connection with human nature is more close and intimate? The sole end of logic is to explain the principles and operations of our reasoning faculty, and the nature of our ideas; morals and criticism regard our tastes and sentiments; and politics consider men as united in society, and dependent on each other. In these four sciences of logic, morals, criticism, and politics, is comprehended almost every thing which it can any way import us to be acquainted with, or which can tend either to the improvement or ornament of the human mind.

"Here, then, is the only expedient from which we can hope for success in our philosophical researches; to leave the tedious, lingering method which we have hitherto followed; and instead of taking, now and then, a castle or village on the frontier, to march up directly to the capital or centre of these sciences, to human nature itself; which being once masters of, we may everywhere else hope for an easy victory. From this station, we

faculties and principles of the mind, are every moment soliciting our notice, and open to our examination a field of discovery as inexhaustible as the phenomena of the material world, and exhibiting not less striking marks of divine wisdom.

While all the sciences and all the pursuits of life have this common tendency to lead our inquiries to the philosophy of human nature, this last branch of knowledge borrows its principles from no other science whatever. Hence there is something in the study of it which is peculiarly gratifying to a reflecting and inquisitive mind, and something in the conclusions to which it leads on which the mind rests with peculiar satisfaction. Till once our opinions are in some degree fixed with respect to it, we abandon ourselves, with reluctance, to particular scientific investigations; and, on the other hand, a general knowledge of such of its principles as are most fitted to excite the curiosity, not only prepares us for engaging in other pursuits with more liberal and comprehensive views, but leaves us at liberty to prosecute them with a more undivided and concentrated attention.

Direct advantages of a study of the phenomena of mind. — It is not, however, merely as a subject of speculative curiosity that the principles of the human mind deserve a careful examination. The advantages to be expected from a successful analysis of it are various; and some of them of such importance, as to render it astonishing, that, amidst all the success with which the subordinate sciences have been cultivated, this, which comprehends the principles of all of them, should be still suffered to remain in its infancy.

I shall endeavor to illustrate a few of these advantages, beginning with what appears to me to be the most important of

may extend our conquests over all those sciences which more intimately concern human life, and may afterward proceed at leisure to discover more fully those which are the objects of pure curiosity. There is no question of importance whose decision is not comprised in the science of man; and there is none which can be decided with any certainty, before we become acquainted with that science."]