ATTENTION, a steady exertion or due applica- I tion of the mind to any object of sense or intellect, in order to its being thoroughly understood, and after wards retained. In its etymology it denotes stretch- 1 in; or straining, from ad and tendo, which not in- • aptly expresses that strong and undivided effort of our powers which is required for giving to an inte- • resting object its due impression.
Whether attention he a distinct and independent power of the mind, which cannot be resolved into any :ling else ; or whether it consist merely in a steady Ind strenuous exercise of any one of our various men :al powers, or organs of external perception, accord ng as the case may require, are questions on which philosophers have differed considerably in opinion. All, however, have agreed, that this species of men :al exertion is indispensible, in order that objects may affect our faculties to such a degree as to be after wards retained in the mind, or distinctly recollected.
Memory," says Mr Locke, " depends much on mention and repetition." C'est l'attention, says Hel 7eti us, phis WC 7120i12$ grande, qui grave plus on moins 9rofondement lea objets dans la nzenzoire. And 2uinctilian makes a similar observation. Nec dubium 7st, says he, speaking of memory, quip plurinzum in 'lac parte, valeat menus intentio, et velut acies lumi a prospectu reruns quas intuetur non aversa. These remarks seem to imply, that attention is volun :ary on our parts ; and so it doubtless is to a certain extent ; but when we are occupied by a very inte resting object, our attention is seized, and fixed beyond our own controul.
In those cases where our attention is entirely en grossed by something that greatly interests the mind, the impressions on the organs of sense seem to pro duce no corresponding effect on our internal powers of perception. A clock, for example, may strike in the room where we are, and if we be deeply engaged in conversation, or in any interesting spetulation, we ;hall not be able, the next moment, to recollect whe ther we heard it or not. The most acute sensation of pain may pass unnoticed, if the attention be vigorous ly directed to another object. In the tumult of a battle, a man may be shot through the body with out knowing any thing of the matter, till he disco vers it by the loss of blood or of strength. And Archimedes', while intent upon the solution of a pro blem, was altogether unconscious of the sacking of Syracuse. In such cases we arc apt to conclude, that the dbjects which act upon our senses, have lost theirin fluence upon our perceptive powers ; though the truth rather. seems to be, that perception still takes place, but that we are unconscious of it, because our atten tion is completely engrossed by some other object. That this is really the case, seems proved by a variety of facts. Thus a person who falls asleep in church, and is suddenly awaked, is unable to recollect the last words of the preacher ; and yet that they affected his perceptive powers appears from this, that he would have instantly awaked, had the preacher made a sud den pause in his discourse.
It seems, therefore, to be essential to memory, even in the very lowest degree, that the perception or thought which we wish to remember, should remain in the mind for a certain space of time, and should be zontemplated by it exclusively of every thing else ; otherwise it will not be recollected even the very mo ment after it has been present in the mind. Hence it happens that, in solitude, or the stillness of the night, when the attention is undistracted by objects, the impression made by any single object is very strong and deep, and the memory becomes ex tremely retentive ; and hence, in the hurry of business, bustle of society, the objects which Press upon i• us in rapid succession, make but a fleeting impression upon the mind, and efface each other from our recol lection.
- It is an important question in the subject of atten tion, whether we have the power of attending to more than one thing at the same instant ; or, in other words, whether we can attend at one and the same instant to objects which we can attend to sepa rately. This question has usually been decided in the negative ; it being supposed to be impossible that the mind can bend its thoughts upon inure than one thing at the same time. It is a consequence of this doctrine, that in a concert of music, instead of attend ing to the different parts of the performance all at once, so as to feel the full effect of the harmony ; the mind must constantly vary its attention from one part of the music to another, although its operations are so rapid as to give us no perception of an interval of time. " The same doctrine," says Mr Stewart, " leads to some curious conclusions with respect to vision. Suppose the eye to be fixed in a particular position, and the picture of an object to be painted on the retina ; Does the mind perceive the complete figure of the object at once, or is this perception the result of the various perceptions we have of the dif ferent points in the outline ? With respect to this question, the principles already stated lead me to con clude, that the mind does at one and the same time perceive every point in the outline of the object, (pro vided the wtole of it be painted on the retina at the same instant,) for perception, like consciousness, is an involuntary operation. As no two points, however, of the outline are in the same direction, every point by itself constitutes just as distinct an object of at tention* to the mind, as if it were separated by an in terval of empty space from all the rest. If the doc trine, therefore, formerly stated be just, it is impossi ble for the mind to attend to more than one of these points at once ; and as the perceptiOn of the figure of the object, implies a knowledge of the relative situa tion of the different points with respect to each c:her, we must conclude, that the perception of figure by the eye, is the result of a number of different acts of attention. These acts of attention, however, are per formed with such rapidity, that the effect, with re spect to us, is the same as if perception were instan taneous.