if we were not certain that this remembrance is not fallacious.

The diversities of memory in different men are very remarkable; and in the fame man the remembrance of fome things is more lafting, and more lively, than that of others. Some of the ideas of memory feem to decay gradually by length of time; fo that there may be fome things which I distinctly remembered seven years ago, but which at present I remember very imperfectly, and which in seven years more (if I live fo long) 1 fhall have utterly forgotten. Hence fome have been led to think, that the evidence of memory decays gradually, from abfolute certainty, through all the degrees of probability, down to that fufpenfe of judgement which we call doubt. They feem to have imagined, that the vivacity of the idea is in fome fort necessary to the establishment of belief. Nay, one author has gone fo far as to fay, that belief is nothing elfe but this vivacity of ideas; as if we never believed what we have no lively conception of, nor doubted of any thing of which we have a lively conception. But this doctrine is fo abfurd, that it hardly deferves confutation. I have a more lively idea of Don Quixote than of the prefent King of Pruffia; and yet I believe that the latter does exist, and that the former never did. When I was a schoolboy, I read an abridge

*

* Treatife of Human Nature, vol. 1. p. 172.

ment

every

ment of the History of Robinson Crufoe, and believed word of it; fince I grew up, I have read that ingenious work at large, and confequently have a much livelier conception of it than before; yet now I believe the whole to be a fiction. Some months ago, I read the Treatife of Human Nature, and have at prefent a pretty clear remembrance of its contents; but I fhall probably forget the greater part in a short time. When that happens, I ought not, according to this theory, to believe that I ever read it. As long, however, as my faculties remain unimpaired, I fear I fhall hardly be able to bring myself to this pitch of fcepticism. No, no; I fhall ever have good reafon to remember my having read that book; however imperfect my remembrance may be, and however little ground I may have to congratulate myself upon my acquaintance with it.

The vivacity of a perception does not seem neceffary to our belief of the existence of the thing perceived. I fee a town afar off; its visible magnitude is not more than an inch fquare, and therefore my perception of it is neither lively nor distinct; and yet I as certainly believe that town to exist, as if I were in the centre of it. I fee an object in motion on the top of yonder hill; I cannot difcern whether it be a man, or a horse, or both; I therefore exert no belief in regard to the class or fpecies of things to which it belongs; but I believe with as much affurance that it ex

ifts, as if I faw it diftinctly in all its parts and dimenfions. We have never any doubt of the existence of an object fo long as we are fure that we perceive it by our fenfes, whether the perception be ftrong or weak, diftinct or confufed; but whenever we begin to doubt, whether the object be perceived by our fenfes, or whether we only imagine that we perceive it, then we likewise begin to doubt of its existence.

These observations are applicable to memory. I faw a certain object fome years ago; my remembrance of it is lefs diftinct now than it was the day after I faw it; but I believe the evidence of my memory as much at prefent as I did then, in regard to all the parts of it which I now am conscious that I remember. Let a past event be ever fo remote in time, if I am confcious that I remember it, I still believe, with equal affurance, that this event did once take place. For what is memory, but a confcioufnefs of our having formerly done or perceived fomething? And if it be true, that something is perceived or done at this prefent moment, it will always be true, that at this moment that thing was perceived or done. The evidence of memory does not decay in proportion as the ideas of memory become less lively; as long as we are confcious that we remember, fo long will the evidence attending that remembrance produce abfolute certainty; and absolute certainty admits not of de

I

grees.

grees. Indeed, as was already obferved, when remembrance becomes fo obfcure, that we are at a lofs to determine whether we remember or only imagine an event, — in this cafe belief will be fufpended till we become certain whether we remember or not; whenever we become certain that we do remember, conviction instantly arises.

Some have fuppofed that the evidence of memory is liable to become uncertain, because we are not well enough acquainted with the difference between memory and imagination, to be able at all times to determine, whether the one or the other be exerted in regard to the events or facts we may have occafion to contemplate. "You fay, that while

you only imagine an event, you neither "believe nor difbelieve the existence or rea

lity of it but that as foon as you become "confcious that you remember it, you in"ftantly believe it to have been real. You "must then know with certainty the difference between memory and imagination, and be able to tell by what marks you diftinguifh the operations of the former "from thofe of the latter. If you cannot do "this, you may mistake the one for the o"ther, and think that you imagine when you

really remember, and that you remember when you only imagine. That belief, "therefore, must be very precarious, which "is built upon the evidence of memory, "fince this evidence is fo apt to be conVOL. I. "founded

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"founded with the vifionary exhibitions of

imagination, which, by your own acknow"ledgement, can never conftitute a founda"tion for true rational belief." This is an objection according to the metaphyfical mode; which, without confulting experience, is fatisfied if a few plaufible words can be put together in the form of an argument: but this objection will have no credit with those who acknowledge ultimate instinctive principles of conviction, and who have more faith in their own feelings than in the fubtleties of logic.

It is certain the vulgar are not able to give a fatisfactory account of the difference between memory and imagination; even philofophers have not always fucceeded in their attempts to illuftrate this point. Mr HUME

tells

*I do not remember where I have met with this argument. Perhaps I may have heard it in converfation.

+ Addifon, in the Spectator, No. 411. feems to confider imagination as a faculty converfant among those i deas only which are derived from the fenfe of feeing. But is not this acceptation of the word too limited? I can invent, and confequently imagine, a tune which I never heard. When I look at Hogarth's humourous print of The Enraged Mufician, I can imagine the several difcordant founds fuppofed to proceed from the perfons and inftruments there affembled. Men born blind, or who have loft all remembrance of light and colours, are as capable of invention, and dream as frequently, as thofe who fee; my learned, ingenious, and worthy friend Dr Blacklock of Edinburgh, who loft his fight at five months old, is an example of both. Some authors have defi

ned