is a habit, which they have been compelled to form by the circumstances, in which they have been placed. In a thousand emergencies they have been obliged to act with quickness, and at the same time with caution; in other words, to examine subjects, and to do it with expedition. In this way the habit spoken of has been formed, viz., of exceeding readiness in all their mental acts.--The oth er prominent mental trait in men in active life arises from this great quickness of intellectual operation, which they are capab e of putting forth. The minute circumstances, which are examined, previous to a judgment on all subjects of difficulty, are passed in review with such rapidity, are made in so very small a degree or rather for so short a time the objects of separate attention, that they vanish and are forgotten. Hence these persons, although the conclusion to which they have come be satisfactory, are unable to state to others all the subordinate steps in the argument. Every thing has once been fairly and distinctly before their own minds, although with that great rapidity, which is always implied in a HABIT; but their argument, as stated in words, owing to their inability to arrest and embody all the evanescent processes of thought, ap pears to others defective and confused.--And in trth it is a known fact, that mere men of business have for the most part no small repugnance to stating their views public. They regard it as a task of much difficulty, a undoubtedly it is to persons of such intellectual habits When obliged to do it, their only resort is to prepare them selves in private, to examine again and again their thought to throw them into words and sentences, and to fix th verbal propositions with as much exactness as possible the memory; otherwise they fail to do justice either themselves or their subject.Stewart's Elements, V 1. CH. V. PT. 2.; Essays, IV, PT. II.; Priestley's Exami tion, SECT. VIII.; Locke's Essay, ВK. II, CH. 33; Brow Lect. XLII, &c.

CHAPTER TWENTIETH.

OF ATTENTION.

§. 223. Of the general nature of attention.

W ITHOUT Considering it necessary to speak of attention as a separate intellectual power or faculty, as some may be inclined to do, it seems to be sufficient to say, that ATTENTION expresses the state of the mind, when it is steadily directed, for some time, whether longer or shorter, to some object of sense or intellect, exclusive of other objects. When we say, that any external object, or any subject of thought, which is purely internal, receives attention, it seems to be the fact, as far as we are able to determine, that the mind is occupied with the subject of its attention, whatever it is, for a certain period, and that all other things are, for the time being, shut out. In other words, the grasp, which the mind fixes upon the object of its contemplations, is an undivided, an unbroken one.

But it is natural to inquire, How this differs from the direction of the mind to a subject in any other case? Since in all instances, the mind, for the time being, is in one state merely; it always embraces one subject or part of a subject, exclusive of others.—The answer to be given to this inquiry is, that in ATTENTION the direction of the mind to a particular subject, or, (what is the same thing,) its continuance in a particular state or series of states, is accompanied with a feeling of preference, desire, or interest; which feeling of desire is the cause of that continuSo that in all cases of attention, the act of the

mind is a complex one, involving two things, (1,) The mere thought or series of thoughts, (2,) The accompanying emotion of interest, which prevents that continual change in the thought, which would otherwise happen.

§. 224. Of different degrees of attention.

In agreement with this view of the subject, we often speak of attention as great or small, as existing in a very high or a very slight degree. When the view of the mind is only momentary, and is unaccompanied, as it generally is at such times, with any force of emotion; then the attention is said to be slight. When it bends itself upon a thought or series of thoughts with earnestness, and for a considerable length of time, and refuses to attend to any thing else; then the attention is said to be intense.

We commonly judge at first of the degree of attention to a subject from the length of time, during which the mind is occupied with it. But when we look a little further, it will be found, that the time will generally depend upon the strength and permanency of the attendant emotion of interest. And hence both the time and the degree of feeling are to be regarded.

Of instances of people, who are able to give but slight attention to any subject of thought, who cannot bring their minds to it with steadiness and power, we every where find multitudes; and there are some instances, where this ability has been possessed in such a high degree as to be worthy of notice. There have been mathematicians, who could investigate the most complicated problems amid every variety and character of disturbance. It was said of Julius Cæsar, that, while writing a despatch, he could at the same time dictate four others to his secretaries, and if he did not write himself could dictate seven letters at once. The chess-player Philidor could direct three games of chess at the same time, of one of which only he requir ed ocular inspection, the moves of the other two being announced to him by an assistant. The moves of the chess-men formed the subject, about which his thoughts were employed, and such was the intensity of interest, tha

the mind found no difficulty in dwelling upon it to the exclusion of other subjects, and for a considerable length of time.

§. 225. Dependence of memory on attention.

There seems to be no fact in mental philosophy more clearly established than this, that memory depends on attention; that is, where attention is very slight, remembrance is weak, and where attention is intense, remembrance continues longer. The following statement of Mr. Hobbes, in his political treatise of the Leviathan, will tend to illustrate this fact.He says, he was once in company, where the conversation turned on the English civil war. A person abruptly asked, in the course of the conversation, What was the value of a Roman denarius? Such a question, so remote from the general direction of the conversation, had the appearance not only of great abruptness, but of impertinence. Mr. Hobbes says, that, on a little reflection, he was able to trace the train of thought, which suggested the question. The original subject of discourse naturally introduced the history of king Charles; the king naturally suggested the treachery of those, who surrendered him up to his enemies; the treachery of these persons readily introduced to the mind the treachery of Judas Iscariot; the conduct of Judas was associated with the thirty pieces of silver, and as the Romans occupied Judea at the time of the crucifixion of the Saviour, the pieces of silver were associated with the Roman denarii. All these trains of thought passed through the mind of the person, who asked the question, in a twinkling; and with good reason Mr. Stewart, in remarking on this anecdote, thinks it not improbable, that he would himself have been unable readily to state the train of ideas, which led to the unexpected inquiry.—Every one is able to detect analogous facts in his own mental experiences. We unexpectedly find ourselves reflecting on a subject, to which we must have been conducted by a long concatenation of thought. But the preceding series, which conducted to the present subject of our medi

tations, occupied our attention for so short a time, that no foundation was laid for the memory, and it has irretrievably vanished.

§. 226. Further illustrations of the dependence of memory on attention.

There are other facts perhaps of a still more obvious and satisfactory nature, which confirm the principle under consideration.(1) Let a person be much engaged in conversation or occupied with any very interesting speculation, and the clock will strike in the room where he is, apparently without his having any knowledge of it. He hears the clock strike as much as at any other time, but, not attending to the perception of sound and having his thoughts directed another way, he immediately forgets.(2) In the course of a single day persons, who are in the habit of winking, will close their eyelids perhaps thousands of times, and as often as they close them, will place themselves in utter darkness. Undoubtedly they are conscious at the time both of closing their eyelids and of being in the dark, but as their attention is chiefly taken up with other things, they have entirely forgotten it.-(3) Whenever we read a book, we do not observe the words merely as a whole, but every letter of which they are made up, and even the minute parts of these letters. But it is merely a glance; it does not for any length of time occupy our attention; we immediately forget, and with great difficulty persuade ourselves, that we have truly perceived the letters of the word. The fact, that every letter is in ordinary cases observed by us, may be proved by leaving out a letter of the word, or by substituting others of a similar form. We readily in reading detect such omissions or substitutions.-(4) An expert accountant can sum up, almost with a single glance of the eye, a long column of figures. The operation is performed almost instantaneously, and yet he ascertains the sum of the whole with unerring certainty. It is impossible, that he should learn the sum without noticing every figure in the whole column, and without allowing each its proper worth;