CHAPTER VIII.

Of Duration.

PASSING Over the preliminary observations, with which Dr. Reid commences his strictures upon Mr. Locke's doctrine about duration, I shall proceed immediately to the consideration of the objections themselves. The idea we have of duration, is thought also to be one of those simple ideas, which could have been obtained neither by sensation nor reflection. "Reflection," says Mr. Locke, "upon the train of ideas, which appear one after another in our minds, is that which furnishes us with the idea of succession; and the distance between any two parts of that succession, is that we call duration." Upon this account so natural and simple, Dr. Reid makes the following remarks—“If it be meant that the idea of succession is prior to that of duration, either in time or the order of nature, this I think, is impossible; because succession, as Dr. Price justly observes, presupposes duration, and can in no sense be prior to it; and therefore, it would be more proper to derive the idea of succession from that of duration. But how do we get the idea of succession? It is, says he, by reflecting upon the train of ideas, which appear one after another in our minds. Reflecting upon the train of ideas, can be nothing but remembering it, and giving attention to what our memory testifies concerning it; for if we did not remember it, we could not have a thought about it." Accordingly, the Dr. maintains, in opposition to Mr. Locke's theory, that our notion of duration is to be traced only to the exercise of memory.

In regard to the objection of Dr. Price, which appears to be concurred in by Dr. Reid, who is certainly ready enough on all occasions, to avail himself of any thing that forins an exception to the principles of Mr. Locke; I have to remark to both of them, that it would always be worth while, fully to study and understand an author, before we undertake to animadvert upon his principles. Mr. Locke had more thoroughly studied and understood these matters, than probably any other man who ever lived, certainly than any author whose works have been conveyed to us. In reference to Price's opinion, that the idea of succession cannot be prior to that of duration, either in time or the order of nature, because succession presupposes duration, and can in no sense be prior to it; I observe that I admit the premises, as I am sure would Mr. Locke, without allowing the conclusion. It is true, that duration is prior in time, and the order of nature to succession, but not in the order of our ideas. It was of the origin and order of ideas, that Mr. Locke was speaking, and not of the order of time or nature, and to this dis tinction, the Drs. do not seem to have adverted. And yet this distinction is all important, as to the decision of the present point. Undoubtedly, between one event and the next that succeeds, which gives us an idea of succession, some time, however small it may be, must intervene, and dura tion, therefore, in the order of nature must precede succession. But not so in the order of our perceptions. Mr. Locke has proved, I think, with unanswerable force of argument, that we are rendered sensible of the existence and progress of time, only by the train of ideas that succeed each other in our minds, as appears from the phenomena of a reverie, and a deliquium in which we are unconscious of the lapse of time, and a sound sleep in which the two points of duration, in which we fall into it and awake, appear to touch each other; and moreover, that if it were possible for us, during any

only, all con

Now, if this

length of time, to keep the same idea perpetually in view of the mind, we should in that case be utterly unconscious that any such time was passing. Those who are accustomed to intense thought or application of the mind to study or busi ness, can easily enter into this view of the subject. The little they are able to judge, concerning the lapse of time in such cases, when a few thoughts occupy and engross their whole attention, can lead them easily to conceive, that could their attention possibly be fixed on one idea sciousness of its course would be at an end. doctrine be just, and it never has been and never can be refuted, suppose a man to begin for the first time to think. We say, that while the first idea occupied his mind, however great the duration in which it might subsist there, he would have no notion of the progress of time, until another made its appearance upon the stage, and that was followed by a third &c., which would give him the idea of succession, and in immediate connection with it, marking the intervals between his ideas, that of duration. Until, therefore, we observed the train of our ideas, as they pass and repass in the mind, we could have no idea of time, and our idea of succession, would be prior to that of duration, though in the order or course of nature, duration must precede succession.

But we have another difficulty to contend with, besides that of Dr. Price, with which this doctrine of Mr. Locke has been embarrassed, for whose origin we are, I believe, entirely indebted to Dr. Reid. The Dr. seems so resolutely predetermined to put Mr. Locke in the wrong, that he disputes with him every inch of ground. Mr. Locke maintains, that our idea of duration, like all our other simple ideas, is derived from reflecting upon the train of our ideas, and assigns to memory no part of the task of giving us this notion; Dr. Reid maintains, that it is to be ascribed exclusively to memory, and perception has nothing to do in the matter. It seems strange to make memory, whose office is to

recall events and ideas that have passed, the sole agent in giving us an idea of time and duration, as if our perceptions were in the interim entirely quiescent; and the opinion is rendered preposterously absurd, when it is recollected, that all that the power of memory can enable us to do, is to revive those perceptions, which had been previously excited, or in other words, recollect what was previously known. How can memory communicate to mankind any intelligence, which they had not before received by perception, when its sole province is to renew that intelligence! But in order, if possible, to bring to a conclusion this great controversy between two such high authorities, I must again beg Dr. Reid to ascertain the exact limits, where perception ceases and memory begins. Is perception to be limited to a second, to a single inhalation of the breath, a pulsation of the heart, or the twinkling of an eye? Until this is ascertained, I am afraid a captious philosophy may raise endless doubts in the case. We folks of vulgar apprehension, are apt to suppose that things which take place at the present time, are objects of perception. As for instance, at this time, the ideas of Bacon, and his method of induction; of Newton, who applied it to natural philosophy; and Locke, who carried it also into the science of mind, may pass rapidly before my view. I avow that I perceive these ideas as passing in my mind at the present. But Dr. Reid complains, that this mode of expression is inaccurate and unphilosophical. "It may be observed," says he, "that if we speak strictly and philosophically, no kind of succession can be an object either of the senses, or of consciousness; because the operations of both are confined to the present point of time, and there can be no succession in a point of time; and on that account, the motion of a body which is a successive change of place, could not be observed by the senses alone, without the aid of memory." This to be sure, is a sublime flight of philosophy, and much beyond the reach of Mr. Locke, and it is

not to be wondered at, that he was too dull to attain to it. The very act of perception itself, one would think takes up more than the Dr.'s single point of time. I take up a cloth of beautiful green, and struck with its appearance, I prolong my observation of its quality, am I not in this case engaged in an act of perception? This may be called, indeed, a doctrine entirely new. "But," says the Dr. "the motion of a body, which is a successive change of place, could not be observed by the senses alone, without the aid of memory." Indeed! This is extraordinary intelligence. I cannot then, see that carriage in motion before me, and should not say that I perceive it in motion, but I remember it in motion. This would be a change in terms, worthy of all remark and consideration. What is understood by that point of time, to which the operation of sense and consciousness are thus confined? Cannot I say, that I perceived that lightning pass from the clouds to the earth? Must memory here lend her aid also? Is not the time taken during a flash of lightning, short enough to form the Dr.'s point of time; and yet I think it demonstrable, that unless there was a succession of ideas in our minds during the flash, we should not perceive that it passed through any portion of space. The Dr. proceeds "As this observation seems to contradict the common sense, and common language of mankind, when they affirm. that they see a body move, and hold motion to be an object of the senses, it is proper to take notice, that this contradiction between the philosopher and the vulgar, is apparent only, and not real. It arises from this, that philosophers and the vulgar, differ in the meaning they put upon what is called the present time, and are thereby led to make a different limit between sense and memory. Philosophers give the name of the present, to that indivisible point of time, which divides the future from the past." Here then, we have arrived at the meaning of the Dr.'s single point of time, and the difficulty is removed, and the whole mystery solved. He means, that