thrown upon this part of our intellectual constitution by the profound investigations of some modern metaphysicians, particularly Berkeley, Condillac, and our present author. It is to those philosophers that we are indebted for the accurate developement of the nature of the process of abstraction, and the important purposes to which it is subservient. The truths which they have discovered have, in part, effected a revolution in the opinions of philosophers regarding the nature of general reasoning and abstract science. Yet we are told that there is nothing new in metaphysics, and that all its principles were familiarly known from the beginning!-In opposition to this strange doctrine we shall only farther add, that the inquiry into the origin of ideas has, in mo dern times, led to some views of the natural history and connexions of our mental operations, exceedingly remote from ordinary observation, and which, as Mr. Stewart observes, are of the greatest importance, because they furnish the only solid basis of that part of logic which relates to the theory of evidence.

We do not think it necessary to enter at any great length into the question, whether or not the philosophy of the mind admits of experiments. Its extensive province in this science must,' says Mr. Stewart, be evident to those who have attended to the use which has been made of this organ of investigation in aiding the analysis of the phenomena of attention, of association, of habit in general, of memory, of imagination; and, above all, those which are connected with the use of language, considered as an instrument of thought and of reasoning.' He farther observes, that to draw the line between the original and acquired perceptions which we receive by some of our senses, is a problem equally difficult and interesting; and of which no pretended solution would, in the present times, attract one moment's notice, which rested on any other basis than that of experiment.' As to the minds of others, it is very true, that we cannot place them at will in new conjunctures, as we can pieces of matter in order to observe the result; but to counterbalance the disadvantages which the philosophy of the mind lies under from its want of experiments made directly and intentionally on the minds of our fellow creatures, it is to be recollected, says Mr. Stewart, that

"Human life exhibits to our observation a boundless variety, both of intellectual and moral phenomena, by a diligent study of which, we may ascertain almost every point that we could wish to investigate, if we had experiments at our command. The difference between observation and experiment, in this instance, considered as sources of knowledge, is merely nominal; amounting to nothing more than this, that the former presents spontaneously to a comprehensive and combining understanding, results exactly similar to those, which the latter would attempt to

ascertian

ascertain by a more easy and rapid process, if it possessed the opportunity. Hardly, indeed, can any experiment be imagined, which has not already been tried by the hand of nature; displaying, in the infinite varieties of human genius and pursuits, the astonishingly diversified effects, resulting from the possible combinations of those elementary faculties and principles of which every man is conscious in himself. Savage society, and all the different modes of civilization ;-the different callings and professions of individuals, whether liberal or mechanical; --the prejudiced clown ;-the factitious man of fashion;-the varying phases of character from infancy to old age;--the prodigies effected by human art in all the objects around us ;--laws,-government,-commerce,-religion ;-but above all, the records of thought, preserved in those volumes which fill our libraries; what are they but experiments, by which Nature illustrates, for our instruction, on her own grand scale, the varied range of Man's intellectual faculties, and the omnipotence of Education in fashioning his mind?'-Prel. Dissert. p. 45.

It is an error to say that Mr. Stewart innovates upon the common understanding of philosophers, in regard to the mode of studying the mind when he brings the observation of these appearances within its province; and it is equally an error to argue that he has himself precluded the metaphysician from this kind of observation, by his own definition, which peremptorily limits the study to attention to the subjects of our consciousness.' This definition is obviously intended to distinguish the inductive investigation of the phenomena of mind from conjectural speculation as to its mechanism, not to prohibit the inquirer from attending, as far as their outward signs will enable him, to the operations and feelings of other minds, as well as to those of which he is immediately conscious in his own. There is no good reason surely why the intellectual philosopher should not endeavour in his inquiries regarding the powers and principles of our common nature to collect whatever information he can from the varied phenomena of human life. The language which Mr. Stewart holds upon this point, is in no respect different from that of preceding philosophers. We could easily accumulate authorities, but shall content ourselves with the following: The records of wars, intrigues, factions, and revolutions,' says Mr. Hume, are so many collections of experiments, by which the moral philosopher fixes the principles of his science, in the same manner as the natural philosopher becomes acquainted with the nature of minerals, and other external objects, by the experiments, which he forms concerning them.'*

It will still be necessary before we close these hasty remarks, to make one or two observations, as to the practical utility of

* Essay on Lib. and Necessity.

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the science of the mind. The Reviewer assumes it as a principle that mere observation never increases our power; and as he denies that the philosophy of the mind has any connexion withexperiment, he accordingly draws the disparaging conclusion that, with regard to it, knowledge is not power.' Mr. Stewart contends, as our readers have seen, that this science does admit of experimental aids; but admitting, he adds, that all the knowledge we possess of mind is derived from observation solely, it would not therefore follow, that the philosophy of the mind must necessarily yield to experimental philosophy in practical utility.' And in illustration of this, he successfully appeals to the practical uses to which the observation of the heavenly bodies was applied, long before any experiments were thought of to perfect the theory of the planetary system.

'It is an old, but very striking reflection,' he impressively observes, that the only accurate knowledge which man possesses of the surface of the earth, has been derived from the previous knowledge he had acquired of the phenomena of the stars. Is it possible to produce a more opposite, or a more undeniable proof of the universality of Bacon's maxim, that knowledge is power,' than a fact which demonstrates the essential aid which man has derived, in asserting his dominion over this lower world, from a branch of science which seems, at first view, fitted only to gratify a speculative curiosity; and which, in its infancy, served to amuse the leisure of the Chaldean shepherd? To those who have imbibed the spirit of Bacon's philosophy, it is superfluous to add, that it was in this refined and enlarged sense of his aphorism, far more than in its obvious and partial application to the new resources which experiments have occasionally lent to the mechanician, that Bacon himself wished to be understood, when he so often repeats it in the same words, with an air of triumph, in the course of his writings.'-Prel. Dissert. p. 39.

Mr. Stewart admits that our conclusions concerning the principles and laws of the human constitution differ, in many respects, from discoveries in physics; but this, he justly observes, ought not to lower our estimate of their practical value, or of the merits of the writers to whom we owe them. Among Bacon's aphorisms there is not,' he adds, ( one sentence which contains a discovery, as that word has been lately defined; but what discoveries can vie with them in the accessions which they have brought to the happiness and to the power of the human race?'

No opinion was ever, we think, founded upon more limited or more erroneous views than that which represents all metaphysical speculation as terminating entirely in itself, and as affording no useful aids in any of our other pursuits.

It is evident, we think, that that science which teaches us how to trace error to its source, how, and within what limits, to conduct our inquiries, in order to conduct them with success, cannot, with

out

out great abuse of language, be said to be unproductive of utility or power. Now, it is the philosophy of the mind, and it alone, which teaches all this. It was the opinion of D'Alembert, who certainly cannot be accused of entertaining too lofty views of the importance of this science, that it furnishes the only means of correcting the errors to which we are liable in all our specu lative inquiries; and he seems to have thought it indispensible to the philosophical character to view it in that light. A l'égard de la métaphysique, says he, il paroit que Newton ne l'avoit pas entièrement négligée. Il étoit trop grand philosophe pour ne pas sentir qu'elle est la base de nos connoissances, et qu'il faut chercher dans elle seule des notions nettes et exactes de tout.*If this account of metaphysical science be just, upon what ground can it be said that it is divested of practical utility? Is not the power which it furnishes of purifying the sources of reasoning, of correcting prejudice and error, a very useful, and noble, and extensive species of power? Do not the inquiries of the metaphysician enable him to regulate his own judgments, and to direct those of others? The effects which his speculations produce are often felt far more widely than any that can be produced by physical discovery. The Reviewer himself tells us, that the famous theory, which accounted for perception, and all our other intellectual operations, by means of ideas or images in the mind, led at length to the annihilating scepticism of Hume. It is also his opinion, that Dr. Reid completely overthrew the hypothesis upon which, according to him, the portentous scepticism of Hume was founded. How then can he deny the character of utility-of power, to those metaphysical inquiries by which human reason was disentangled from the effects of such a system of scepticism? Dr. Reid's success was entirely owing to a more correct analysis of certain intellectual phenomena than had been accomplished before; and yet we are told that this sort of analysis cannot be applied to any practical purposes,--by a writer too who admits, that it took away the supports of a system of scepticism, eminently calculated to unhinge the opinions and principles of mankind. No one who is at all conversant in the history of philosophy can be ignorant of the famous hypothesis of the real existence of abstract ideas, and the obstacles which it opposed to the progress of knowledge. That absurd hypothesis, as has been shown by Berkeley and, more largely, by Condillac, was the cause that all speculation, and all abstract science were long involved in error and mysticism. Its overthrow must, therefore, have proved a general benefit to philosophy; and this was accomplished by the accurate examination of the laws of the mind in the case of ab

* Discours Prélim. de l'Encyclop.

straction.

straction. We have here, then, a proof that the philosophy of the mind exerts an influence over all the other sciences, and that they have all a near interest in its successful cultivation.

6

We are told by Locke in the simple but instructive account which he gives of the origin of his immortal work, that upon an occasion when he was engaged in a philosophical discussion with some of his friends,' they all at once came to a stand, from the difficulties which rose on every side. At last, says he, it came into my thoughts that we took a wrong course, and that before we set ourselves upon inquiries of that nature, it was necessary to examine what objects our understandings were and were not fitted to deal with? It is impossible we think to know any thing of the history of the manifold errors which have arisen from a wrong course' of inquiry, and from not knowing what things the understanding was and was not fitted to deal with,' without perceiving the vast importance of the philosophy of the mind. The whole system of philosophical knowledge remained corrupt for ages, from the ignorance in which men were of the limits of the understanding, and of the rules which its laws enjoin them invariably to follow in the search of truth. What errors, what waste of ingenious labour, in physics, has not the attempt to discover the causes or necessary connexions of natural events produced! The whole history of that science is full of hypotheses, which arose from the misconceptions of philosophers regarding physical causes or connexions. The vain pursuit of these has therefore operated as a material obstruction to the progress of genuine science. Now if it be indisputable, as it unquestionably is, that metaphysical analysis has at length demonstrated the folly of such pursuits, and fixed the true course and boundaries of physical inquiry; how short-sighted must not that view of the philosophy of the mind appear, which represents it as without influence upon the other sciences, and entirely destitute of the character of practical utility!

The great father of experimental philosophy thought more justly of this important science. He points out the study of the powers and faculties of the mind, as that which furnishes the keys of all other knowledge.* 'As the hand,' says he,' is instrumental to all other instruments, so is the knowledge of the mind instrumental to all other knowledge.' And no observation can appear more just, when we consider that it was from this source that he derived his great organon of discovery. To his just and profound views of the laws of the human understanding, we are indebted for that inductive logic, which has exercised so vast and so beneficial an influence on the progress of human knowledge. What indeed is the inductive * De Augmen. Scient. Lib. 5. Cap. 1.

philosophy