objects about which it is conversant; for the information which we already possess gives us an interest in every new truth and every new fact which have any relation to it. In most cases, our habits of inattention may be traced to a want of curiosity; and therefore such habits are to be corrected, not by endeavouring to force the attention in particular instances, but by gradually learning to place the ideas which we wish to remember in an interesting point of view.

3. When we first enter on any new literary pursuit, we are unable to make a proper discrimination in point of utility and importance among the ideas which are presented to us; and by attempting to grasp at everything, we fail in making those moderate acquisitions which are suited to the limited powers of the human mind. As our information extends, our selection becomes more judicious and more confined; and our knowledge of useful and connected truths advances rapidly, from our ceasing to distract the attention with such as are detached and insignificant.

4. Every object of our knowledge is related to a variety of others; and may be presented to the thoughts, sometimes by one principle of association, and sometimes by another. In proportion, therefore, to the multiplication of mutual relations among our ideas, (which is the natural result of growing information, and in particular, of habits of philosophical study,) the greater will be the number of occasions on which they will recur to the recollection, and the firmer will be the root which each idea, in particular, will take in the memory.

It follows, too, from this observation, that the facility of retaining a new fact or a new idea will depend on the number of relations which it bears to the former objects of our knowledge; and, on the other hand, that every such acquisition, so far from loading the memory, gives us a firmer hold of all that part of our previous information with which it is in any degree connected.

It may not, perhaps, be improper to take this opportunity of observing, although the remark be not immediately connected with our present subject, that the accession made to the stock of our knowledge, by the new facts and ideas which we acquire, is not to be estimated merely by the number of these facts and

ideas considered individually, but by the number of relations which they bear to one another, and to all the different particulars which were previously in the mind; for "new knowledge," as Mr. Maclaurin has well remarked,1 "does not consist so much in our having access to a new object, as in comparing it with others already known, observing its relations to them, or discerning what it has in common with them, and wherein their disparity consists: and therefore, our knowledge is vastly greater than the sum of what all its objects separately could afford; and when a new object comes within our reach, the addition to our knowledge is the greater, the more we already know; so that it increases, not as the new objects increase, but in a much higher proportion."

[The above passage may serve to illustrate an ingenious and profound remark of Duclos, in his Considérations sur les Mours. "If education were judiciously conducted, the mind would acquire a great stock of truths with greater ease than it acquires a small number of errors. Truths have among themselves a relation and connexion, certain points of contact which are equally favourable to the powers of apprehension and of memory; while, on the other hand, errors are commonly so many insulated propositions, of which, though it be difficult to shake off the authority, it is easy to prevent the original acquisition.”]

5. In the last place, the natural powers of memory are, in the case of the philosopher, greatly aided by his peculiar habits of classification and arrangement. As this is by far the most important improvement of which memory is susceptible, I shall consider it more particularly than any of the others I have mentioned.

The advantages which the memory derives from a proper classification of our ideas, may be best conceived by attending to its effects in enabling us to conduct with ease the common business of life. In what inextricable confusion would the lawyer or the merchant be immediately involved, if he were to deposit in his cabinet promiscuously the various written documents which daily and hourly pass through his hands? Nor 1 See the conclusion of his View of Newton's Discoveries.

could this confusion be prevented by the natural powers of memory, however vigorous they might happen to be. By a proper distribution of these documents, and a judicious reference of them to a few general titles, a very ordinary memory is enabled to accomplish more than the most retentive, unassisted by method. We know with certainty where to find any article we may have occasion for if it be in our possession, and the search is confined within reasonable limits, instead of being allowed to wander at random amidst a chaos of particulars.

Or, to take an instance still more immediately applicable to our purpose: suppose that a man of letters were to record in a commonplace book, without any method, all the various ideas and facts which occurred to him in the course of his studies, what difficulties would he perpetually experience in applying his acquisitions to use? and how completely and easily might these difficulties be obviated by referring the particulars of his information to certain general heads? It is obvious, too, that by doing so he would not only have his knowledge much more completely under his command, but as the particulars classed together would all have some connexion more or less with each other, he would be enabled to trace with advantage those mutual relations among his ideas, which it is the object of philosophy to ascertain.

A commonplace book conducted without any method, is an exact picture of the memory of a man whose inquiries are not directed by philosophy. And the advantages of order in treasuring up our ideas in the mind, are perfectly analogous to its effects when they are recorded in writing.

Nor is this all. In order to retain our knowledge distinctly and permanently, it is necessary that we should frequently recall it to our recollection. But how can this be done without the aid of arrangement? Or supposing that it were possible, how much time and labour would be necessary for bringing under our review the various particulars of which our information is composed? In proportion as it is properly systematized, this time and labour are abridged. The mind dwells habitually, not on detached facts, but on a comparatively small number of

general principles; and by means of these it can summon up, as occasion may require, an infinite number of particulars associated with them, each of which, considered as a solitary truth, would have been as burdensome to the memory as the general principle with which it is connected.1

I would not wish it to be understood from these observations, that philosophy consists in classification alone, and that its only use is to assist the memory. I have often, indeed, heard this asserted in general terms; but it appears to me to be obvious, that although this be one of its most important uses, yet something more is necessary to complete the definition of it. Were the case otherwise, it would follow that all classifications are equally philosophical, provided they are equally comprehensive. The very great importance of this subject will, I hope, be a sufficient apology for me in taking this opportunity to correct some mistaken opinions which have been formed concerning it.

SECT. V.-CONTINUATION OF THE SAME SUBJECT.

AID WHICH THE MEMORY DERIVES FROM PHILOSOPHICAL ARRANGEMENT.

It was before observed that the great use of the faculty of memory, is to enable us to treasure up for the future regula

1

1 [It is very justly and ingeniously remarked by Dr. Priestley, that the more we know of any branch of science, the less is the compass into which we are able to bring its principles, provided the facts from which they are inferred be numerous." The reason is, that "in an advanced state of knowledge, we are able to reduce more of the particular into general observations; whereas, in the infancy of a science, every observation is an independent fact, and in delivering the principles of it, they must all be distinctly mentioned, so that, though a selection may be made, a proper abridgment is impossible."

In illustration of this, the same author

observes farther, that "Notwithstanding the vast additions that have been made to the science of optics within the last hundred years, a judicious summary of the whole will be much shorter now than it would have been a century ago; and yet it is probable, much larger than there will be any necessity of making it a century hence; as it may be presumed, that by that time a connexion will be traced between many facts which now appear to be unconnected and independent of one another, and there fore require to be recited separately.”— History of Discoveries relating to Vi sion, &c., p. 768.]

tion of our conduct, the results of our past experience, and of our past reflections. But in every case in which we judge of the future from the past, we must proceed on the belief that there is in the course of events, a certain degree at least of uniformity. And accordingly, this belief is not only justified by experience, but (as Dr. Reid has shewn in a very satisfactory manner) it forms a part of the original constitution of the human mind. In the general laws of the material world, this uniformity is found to be complete; insomuch that in the same combinations of circumstances, we expect, with the most perfect assurance, that the same results will take place. In the moral world, the course of events does not appear to be equally regular, but still it is regular, to so great a degree as to afford us many rules of importance in the conduct of life.

A knowledge of nature, in so far as it is absolutely necessary for the preservation of our animal existence, is obtruded on us, without any reflection on our part, from our earliest infancy. It is thus that children learn of themselves to accommodate their conduct to the established laws of the material world. In doing so they are guided merely by memory, and the instinctive principle of anticipation, which has just been mentioned.

In forming conclusions concerning future events, the philosopher as well as the infant can only build with safety on past experience; and he, too, as well as the infant, proceeds on an instinctive belief, for which he is unable to account, of the uniformity of the laws of nature. There are, however, two important respects which distinguish the knowledge he possesses from that of ordinary men. In the first place, it is far more extensive, in consequence of the assistance which science gives to his natural powers of invention and discovery. Secondly, it is not only more easily retained in the memory, and more conveniently applied to use, in consequence of the manner in which his ideas are arranged; but it enables him to ascertain by a process of reasoning, all those truths which may be synthetically deduced from his general principles. The illustration of these particulars will lead to some useful remarks, and will at the same time shew, that in discussing the subject