II.

attention and memory is to enable us to treasure up the refults CHA P. of our experience and reflexion for the future regulation of our conduct, it would have anfwered no purpose for the author of our nature to have extended their province to thofe intervals of time, which we have no occafion to estimate in the common business of life. All the intellectual proceffes I have mentioned are fubfervient to fome particular end, either of perception or of action; and it would have been perfectly fuperfluous, if, after this end were gained, the fteps which are inftrumental in bringing it about, were all treasured up in the memory. Such a conftitution of our nature would have had no other effect but to store the mind with a variety of ufelefs particulars.

AFTER all I have faid, it will perhaps be ftill thought, that fome of the reafonings I have offered are too hypothetical; and it is even poffible, that fome may be disposed rather to dispute the common theory of vifion, than admit the conclufions I have endeavoured to establish. To fuch, I flatter myself that the following confiderations may be of ufe, as they afford a more palpable inftance, than any I have yet mentioned, of the rapidity with which the thoughts may be trained by practice, to fhift from one thing to another.

---

WHEN an equilibrift balances a rod upon his finger, not only the attention of his mind, but the obfervation of his eye, is conftantly requifite. It is evident that the part of his body which fupports the object is never wholly at reft; otherwise the object would no more stand upon it, than if placed in the fame pofition upon a table. The equilibrift, therefore, muft watch, in the very beginning, every inclination of the objec

from

II.

CHAP. from the proper position, in order to counteract this inclination by a contrary movement. In this manner, the object has never time to fall in any one direction, and is fupported in a way somewhat analogous to that in which a top is supported on a pivot, by being made to fpin upon an axis.-That a person should be able to do this in the cafe of a fingle object, is curious; but that he should be able to balance in the fame way, two, or three, upon different parts of his body, and at the fame time balance himself on a small cord or wire, is indeed wonderful. Nor is it poffible to conceive that, in such an instance, the mind, at one and the fame moment, attends to these different equilibriums; for it is not merely the attention which is requifite, but the eye. We must therefore conclude, that both of these are directed fucceffively to the different equilibriums, but change from one object to another with such velocity, that the effect, with respect to the experiment, is the fame as if they were directed to all the objects conftantly.

It is worth while to remark farther, with respect to this last illustration, that it affords direct evidence of the poffibility of our exerting acts of the will, which we are unable to recollect; for the movements of the equilibrift do not fucceed each other in a regular order, like thofe of the harpfichord player, in performing a piece of mufic; but must in every instance be regulated by accidents, which may vary in numberless respects, and which, indeed, muft vary in numberless refpects, every time he repeats the experiment: and therefore, although, in the former cafe, we should fuppofe, with Hartley," that the mo"tions cling to one another, and to the impreffions of the

"notes,

66

II.

notes, in the way of affociation, without any intervention of CHA P. "the state of mind called will," yet, in this inftance, even the poffibility of fuch a fuppofition is directly contradicted by the fact.

THE dexterity of jugglers, (which, by the way, merits a greater degree of attention from philofophers, than it has yet attracted,) affords many curious illuftrations of the fame doctrine. The whole of this art seems to me to be founded on this principle; that it is poffible for a perfon, by long practice, to acquire a power, not only of carrying on certain intellectual proceffes more quickly than other men, (for all the feats of legerdemain suppose the exercise of obfervation, thought, and volition,) but of performing a variety of movements with the hand, before the eyes of a company, in an interval of time too short to enable the spectators to exert that degree of attention, which is neceffary to lay a foundation for memory *

As fome philofophers have disputed the influence of the will in the cafe of habits, fo others (particularly Stahl and his followers) have gone into the oppofite extreme, by referring to the will all the vital motions. If it be admitted, (say these philofophers,) that there are inftances in which we will an effect, without being able to make it an object of attention, is it not poffible that, what we commonly call the vital and involuntary motions, may be the confequences of our own thought and volition? But there is furely a wide difference between thofe cases, in which the mind was at first conscious of thought and

See Note [E].

volition,

II.

CHA P. volition, and gradually loft the power of attending to them, from the growing rapidity of the intellectual procefs; and a cafe in which the effect itself is perfectly unknown to the bulk of mankind, even after they arrive at maturity, and in which this effect has continued to take place with the most perfect regularity, from the very beginning of their animal existence, and long before the first dawn of either reflexion or experience.

SOME of the followers of Stahl have ftated the fact rather inaccurately, even with respect to our habitual exertions. Thus Dr. Porterfield, in his Treatife on the Eye, is at pains to prove, that the foul may think and will without knowledge or consciousness. But this, I own, is to me inconceivable. The true ftate of the fact, I apprehend, is, that the mind. may think and will, without attending to its thoughts and volitions, fo as to be able afterwards to recollect them.-Nor is this merely a verbal criticism; for there is an important difference between consciousness and attention, which it is very neceffary to keep in view, in order to think upon this fubject with any degree of precision. *The one is an involuntary state of the mind; the other is a voluntary act; the one has no immediate connexion with memory; but the other is fo effentially fub

* The distinction between attention and consciousness is pointed out by Dr. Reid, in his Effays on the Intellectual Powers of Man, p. 65. "Attention is a voluntary act; it requires an active exertion to begin and to continue it; " and it may be continued as long as we will; but confcioufnefs is involuntary, "and of no continuance, changing with every thought." The fame author has remarked, that these two operations of the mind have been frequently confounded by philofophers, and particularly by Mr. Locke.

fervient

fervient to it, that, without fome degree of it, the ideas and perceptions which pass through the mind, feem to leave no trace behind them.

WHEN two perfons are speaking to us at once, we can attend to either of them at pleasure, without being much disturbed by the other. If we attempt to liften to both, we can understand neither. The fact feems to be, that when we attend conftantly to one of the speakers, the words spoken by the other make no impreffion on the memory, in confequence of our not attending to them; and affect us as little as if they had not been uttered. This power, however, of the mind to attend to either speaker at pleasure, fuppofes that it is, at one and the fame time, conscious of the sensations which both produce.

ANOTHER well-known fact may be of ufe in illustrating the same distinction. A person who accidentally lofes his fight, never fails to improve gradually in the fenfibility of his touch.Now, there are only two ways of explaining this. The one is, that, in confequence of the lofs of the one fenfe, fome change takes place in the physical conftitution of the body, fo as to improve a different organ of perception. The other, that the mind gradually acquires a power of attending to and remembering those flighter fenfations of which it was formerly conscious, but which, from our habits of inattention, made no impreffion whatever on the memory. No one, furely, can hesitate for a moment, in pronouncing which of these two fuppofitions is the more philofophical.

CHA P.
II.