work, have I recollected the advice of Bergman to Morveau.* * "In reforming the nomenclature of "chemistry, fpare no word which is improper. "They who understand the fubject already, will fuf"fer no inconvenience; and they to whom the sub"ject is new, will comprehend it with the greater "facility." But it belongs to fuch authors alone, as have extended the boundaries of science by their own discoveries, to introduce innovations in language with any hopes of fuccefs.

CHAPTER SIXTH.

OF MEMORY.

SECTION I.

General Obfervations on Memory...

AMONG the various powers of the underftanding there is none which has been fo attentively examined by philofophers, or concerning which fo many important facts and obfervations have been collected, as the faculty of Memory. This is partly to be afcribed to its nature, which renders it eafily dif tinguishable from all the other principles of our conftitution, even by thofe who have not been accuftomed to metaphyfical invefligations, and partly to

"Lesavant Professeur d'Upsal, M. Bergman, écrivoit " à M. de Morveau dans les derniers temps de sa vie, ne "faites graces à aucune denomination impropre. Ceux qui savent déja entendront toujours; ceux qui ne savent pas encore entendront plutôt." Methode de Nomenclat. Chèmique, par MM. MORVEAU, LAVOISIER, &c.

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its immediate fubferviency, not only to the purfaits of fcience, but to the ordinary bufinefs of life; in confequence of which, many of its moft curious laws had been observed, long before any analysis was attempted of the other powers of the mind; and have for many ages, formed a part of the common maxims which are to be found in every treatife of education. Some important remarks on the fubject may, in particular, be collected from the writings of the ancient rhetoricians.

The word Memory is not employed uniformly in the fame precife fenfe; but it always expreffes fome modification of that faculty, which enables us to treasure up, and preferve for future ufe, the knowledge we acquire; a faculty which is obviously the great foundation of all intellectual improvement, and without which, no advantage could be derived from the most enlarged experience. This faculty implies two things: a capacity of retaining knowledge; and a power of recalling it to our thoughts when we have occafion to apply it to use. The word Memory is fometimes employed to exprefs the capacity, and fometimes the power. When we speak of a retentive memory, we ufe it in the former sense ; when, of a ready memory, in the latter.

The various particulars which compose our stock of knowledge are, from time to time, recalled to our thoughts, in one of two ways; fometimes they recur to us fpontaneoufly, or at leaft, without any interference on our part; in other cafes, they are recalled, in confequence of an effort of our will. For the former operation of the mind, we have no appropriated name in our language, diftinct from Memory. The latter, too, is often called by the fame name, but is more properly diftinguished by the word Recollection.

There are, I believe, fome other acceptations befides thefe, in which the word Memory has been oc

cafionally employed; but as its ambiguities are not of fuch a nature as to miflead us in our prefent inquiries, I fhall not dwell any longer on the illustration of diftinctions, which to the greater part of readers might appear uninteresting and minute. One diftinction only, relative to this fubject, occurs to me, as deferving particular attention.

The operations of Memory relate either to things and their relations, or to events. In the former cafe, thoughts which have been previoufly in the mind, may recur to us, without fuggefting the idea of the paft, or of any modification of time whatever; as when I repeat over a poem which I have got by heart or when I think of the features of an abfent friend. In this last instance, indeed, philofophers diftinguish the act of the mind by the name of Conception; but in ordinary difcourfe, and frequently even in philofophical writing, it is confidered as an exertion of Memory. In thefe and fimilar cafes, it is obvious that the operations of this faculty do not neceffarily involve the idea of the past.

The cafe is different with refpect to the memory of events. When I think of thefe, I not only recal to the mind the former objects of its thoughts, but I refer the event to a particular point of time; fo that of every such act of memory, the idea of the paft is a neceffary concomitant.

I have been led to take notice of this diftinction, in order to obviate an objection which some of the phenome of Memory feem to prefent, against a doctrine which I formerly ftated, when treating of the powers of Conception and Imagination.:

It is evident, that when I think of an event, in which any object of sense was concerned, my recollection of the event must neceffarily involve an act of Conception. Thus, when I think of a dramatic reprefentation which I have recently feen, my recollection of what I faw, neceffarily involves a concep

tion of the different actors by whom it was perform. ed. But every act of recollection which relates to events, is accompanied with a belief of their paft ex. iftence. How then are we to reconcile this conclufion with the doctrine formerly maintained concerning Conception, according to which every exertion of that power is accompanied with a belief, that its object exifts before us at the present moment?

The only way that occurs to me of removing this difficulty, is by fuppofing, that the remembrance of a paft event, is not a fimple act of the mind: but that the mind firft forms a conception of the event, and then judges from circumftances, of the period of time to which it is to be referred: a fuppofition which is by no means a gratuitous one, invented to anfwer a particular purpofe; but which, as far as I am able to judge, is agreeable to fact: for if we have the power, as will not be difputed, of conceiving a past event without any reference to time, it follows, that there is nothing in the ideas or notions which memory prefents to us, which is neceffarily acco mpanied with a belief of past existence, in a way analogous to that in which our perceptions are accompanied with a belief of the prefent exiftence of their objects; and therefore, that the reference of the event to the particular period at which it happened, is a judgment founded on concomitant circumftances. So long as we are occupied with the conception of any particular object connected with the event, we believe the prefent exiftence of the object; but this belief, which in moft cafes, is only momentary, is inftantly corrected by habits of judging acquired by experience; and as foon as the mind is difengaged from fuch a belief, it is left at liberty to refer the event to the period at which it actually happened. Nor will the apparent inftantaneoufnefs of fuch judgments be confidered as an unfurmountable objection to the doctrine now advanced, by

those who have reflected on the perception of diftance obtained by fight, which, although it seems to be as immediate as any perception of touch, has been fhewn by philofophers to be the refult of a judgment, founded on experience and obfervation. The reference we make of paft events to the particular points of time at which they took place, will, I am inclined to think, the more we confider the subject, be found the more ftrikingly analogous to the efti mates of distance we learn to form by the eye.

Although, however, I am, myself, fatisfied with the conclufion to which the foregoing reafonings lead, I am far from expecting that the cafe will be the fame with all my readers. Some of their objections, which I can easily anticipate, might, I believe, be ob viated by a little farther difcuffion; but as the queftion is merely a matter of curiofity, and has no neceffary connection with the observations I am to make in this Chapter, I fhall not profecute the fubject at prefent. The opinion, indeed, we form concerning it, has no reference to any, of the doctrines maintained in this work, excepting to a particular fpeculation concerning the belief accompanying conception, which I ventured to ftate, in treating of that fubject, and which, as it appears to be extremely doubtful to fome whofe opinions I refpect, I propofed with a degree of diffidence fuitable to the dif ficulty of fuch an enquiry. The remaining obfervations which I am to make on the power of memory, whatever opinion may be formed of their importance, will furnish but little room for a diverfity of judgment concerning their truth.

In confidering this part of our constitution, one of the most obvious and ftriking queftions that occurs, is, what the circumftances are which determine the memory to retain fome things in preference to others? Among the fubjects which fucceffively occupy our thoughts, by far the greater number vanish,