of thought as it passes in the mind, so as to be able afterwards to recollect every different step of the process; a habit which, in some cases, has such an influence on the intellectual powers, that there are men who, even in their private speculations, not only make use of words as an instrument of thought, but form these words into regular sentences.

137. When a train of thought leads to any interesting conclusion, or excites any pleasant feeling, it becomes peculiarly difficult to arrest our fleeting ideas, because the mind has little inclination to retrace the steps by which it arrived at the pleasure which it now feels.

Obs. This is one great cause of the difficulty attending philosophical criticism; and exquisite sensibility, so far from being useful in this species of criticism, both gives a disrelish for the study and disqualifies for pursuing it legitimately.

138. There is a great variety of cases, in which the mind apparently exerts different acts of attention at once; but from the illustrations which we have given of the astonishing rapidity of thought, it is obvious, that those acts are not coexistent; or, in other words, that we do not attend, at one and the same instant, to objects which we can attend to separately.

Illus. 1. The case of the equilibrist and rope-dancer affords direct evidence of the possibility of the mind's exerting different successive acts in an interval of time so short, as to produce the same sensible effect as if they had been exerted at one and the same moment. In this case, every movement of the eyes precedes a thought of the mind, every thought a volition, every volition a separate action of muscular force, but so rapidly does each of these succeed the other, that though they seem instantaneous, they cannot be mathematically coexistent.

2. In a concert of music, a good ear can attend to the different parts of the music separately, or can attend to them all at once, and feel the full effect of the harmony; but the mind is constantly varying its attention from one part of the music to the other, and its operations are so rapid as to give us no perception of an interval of time.

3. In viewing a picture, the mind at one and the same time perceives every point in the outline of the object (provided the whole be painted on the retina at one and the same instant), for perception, like consciousness, is an involuntary operation; but as no two points of the outline are in the same direction, every point, by itself, constitutes just as distinct an object of attention to the mind, as if it were separated by an interval of empty space from all the rest. As, therefore, it is impossible for the mind to attend to more than one of those points at once, and as the perception of the

figure of the object implies a knowledge of the relative situation of the different points with respect to each other, we must conclude that the perception of the figure by the eye, is the result of a number of different acts of attention. These acts of attention, however, are performed with such rapidity, that the effect, with respect to us, is the same as if the perception were instantaneous.

Corol. 1. If the perception of visible figure were an immediate consequence of the picture on the retina, we should have, at the first glance, as distinct an idea of a figure of a thousand sides, as of a triangle or a square; for when the figure is very simple, the process of the mind is so rapid, that the perception seems to be instantaneous; but when the sides are multiplied beyond a certain number, the interval of time necessary for these different acts of attention becomes perceptible.

2. If these reasonings be admitted, it will follow, that without the faculty of memory, we could have no perception of visible figure.

CHAPTER V.

OF CONCEPTION.

139. CONCEPTION is that faculty of the mind which enables us to form a notion of an absent object of perception; or of a sensation which it has formerly felt.

Illus. When a painter paints a picture of a friend who is absent or dead, he is commonly said to paint from memory; and the expression is sufficiently correct for common conversation. But, in an analysis of the powers of the mind, there is ground for a distinction between conception and the other powers, with some of which it is often confounded. The power of conception enables the painter to make the features of his friend an object of thought, so as to copy the resemblance; the power of memory recognizes these features as a former object of perception. Thus, conception is distinguished from memory. Every act of memory includes an idea of the past; conception implies no idea of time whatever.

Note. Shakspeare calls this power the mind's eye.

Hamlet. My father! Methinks I see my father.
Horatio. Where, my lord?

Hamlet. In my mind's eye, Horatio.

HAMLET, Act 1. Scene 4.

140. Conception corresponds, according to the view we have taken of it, to what the schoolmen call simple apprehension; with this difference only, that they include, under this name, our apprehension of general propositions; whereas the word conception is, in this volume, limited to our sensations and the objects of our perceptions.

Illus. This distinction is warranted by the authority of philosophers in a case perfectly analogous. Thus, in ordinary language, we apply the same word perception to the knowledge which we have by our senses of external objects, and to our knowledge of a speculative truth. And between the conception of a truth, and the conception of an absent object of sense, there is obviously as wide a difference as between the perception of a tree and the perception of a mathematical theorem. Conception, therefore, is that faculty whose province it is to enable us to form a notion of our past sensations, or of the objects of sense that we have formerly perceived.

141. Conception is frequently used as synonymous with imagination, but imagination is distinguished from conception as a part from a whole.

Illus. The business of conception is to present us with an exact transcript of what we have felt or perceived. But we have, moreover, a power of modifying our conceptions, by combining the parts of different conceptions together, so as to form new wholes of our own creation. This power, according to Mr. Stewart, is expressed by the word imagination; and he apprehends, that this is the proper sense of the word; if imagination be the power which gives birth to the productions of the poet and the painter. This is not a simple faculty of the mind, for it presupposes abstraction, to separate from each other qualities and circumstances which have been perceived in conjunction; and also judgment and taste to dírect us, in forming the combinations.

Obs. People, in common discourse, often use the phrase thinking upon an object, to express what we have illustrated as the conception of it. Shakspeare, whose talent for philosophizing was equal to his imaginative powers as a poet, uses, in the following passage, the former of these phrases in the same sense as we should use conception, and the words imagination and apprehension are synony mous with each other.

Who can hold a fire in his hand
By thinking on the frosty Caucasus ?
Or cloy the hungry edge of appetite
By bare imagination of a feast?
Or wallow naked in December's snow,
By thinking on fantastic summer's heat?
Oh no! the apprehension of the good
Gives but the greater feeling to the worse.
K. RICHARD II. Act 1. Scene 6.

142. We can conceive the objects of some senses much more easily than those of others. And, first, as to visible objects; we can conceive the structure of a building that is familiar to us much more easily than a particular sound, a particular taste, or a particular pain which we have formerly felt.

Illus. The peculiarity in the case of visible objects seems to arise from this; that when we think of a sound or of a taste, the object

of our conception is one single detached sensation; whereas every visible object complex; and the conception that we form of it is aided by the association of ideas. We attend not, at one instant, to every point of the picture of an object on the retina (Corol. 1. Art. 138); nor at one instant, therefore, do we form a conception of the whole of any visible object; but our conception of the object as a whole, is the result of many conceptions. The association of ideas connects the different parts together, and presents them to the mind in their proper arrangement; and the various relations which these parts bear to one another in point of situation, contribute greatly to strengthen the associations. This illustration is confirmed by the fact, that it is more easy to remember a succession of sounds, than any particular sound which we have heard detached and unconnected. The war-hoop of the American Indians, the yell of Cossacks, the shout of victory, or any cry that alarmed or encouraged us, may be considered a particular sound, but the conception of such a sound depends on the association of ideas.

143. The power of conceiving visible objects, like other powers that depend on the association of ideas, may be greatly improved by habit.

Illus. A person accustomed to drawing, retains a much more perfect notion of a building, or of a landscape, which he has seen, than one who has never practised that art. A portrait painter traces the forms of the human body from memory, with as little exertion as he employs in writing the letters which compose his name.

144. Secondly. In the power of conceiving colors, too, there are striking differences among individuals; and probably, in the greater number of instances, the supposed defects of sight, in this respect, ought rather to be ascribed to a defect in the power of conception, than in the organ of the perception of color.

Illus. We often see two men who are perfectly sensible of the difference between two colors when they are presented to them, who cannot give names to these colors with confidence, when they see them apart; and are perhaps apt to confound the one with the other. They feel the sensation of color like other men, it should seem, when the object is present, but are incapable, probably in consequence of some early habit of inattention, to conceive the sensation

distinctly when the object is removed. Without this power of conception, Mr. Stewart thinks, that it is evidently impossible for them, how lively soever their sensations may be, to give a name to any color; for the application of the name supposes not only a capacity of receiving the sensation, but a power of comparing it with one formerly felt. In some cases, perhaps, the sensation is not felt at all; and in others, the faintness of the sensation may be one cause of those habits of inattention, from which the incapacity of conception has arisen.

145. Thirdly. A talent for lively description, at least in the case of sensible objects, depends chiefly on the degree

in which the describer possesses the power of conception. Nor is it merely to the accuracy of our description, in common conversation, that this power is subservient; it contributes more than any thing else to render them striking and expressive to others, by guiding us to a selection of such circumstances as are most prominent and characteristical.

Obs. The best rule for descriptive composition, is, to attend to those rules which make the deepest impression on our own minds. Now, these particulars are in general the outline; and it is the province of conception to neglect a minute specification of particulars, and to select only such as struck us most at the moment the object we are describing from recollection was present to our view. A person may therefore write a happier description of an object from the conception than from the actual perception of that object.

146. The foregoing observations, with their respective illustrations, apply to conception, as distinguished from imagination. The two faculties, we observed, are very nearly allied; and are frequently so blended and compounded, that it is difficult to say, to which of the two some particular operations of the mind are to be referred. There are also general facts which hold equally with respect to both.

147. The exercise both of conception and imagination is always accompanied with a belief that their objects exist.

Illus. 1. Thus, when the imagination is very lively, as in dreaming and madness, a real existence is ascribed to its objects; and in the case, too, of those who, in spite of their own general belief of the absurdity of the vulgar stories of apparitions, dare not trust themselves alone with their own imaginations in the dark, we have all the evidence that the thing admits of, that imagination is attended with belief. Dr. Reid's friend, who could not sleep in a room alone, nor go alone into a room in the dark, felt and acted in the same manner as he would have done, if he had believed that the objects of his fear were real, which is the only proof that the philosophers produce, or can produce, of the belief which accompanies perception.

2. The painter, who conceives the face and figure of an absent friend, in order to draw his picture, believes, for the moment, that his friend is before him. The belief is only momentary, for it is extremely difficult, in our waking hours, to keep up a steady and undivided attention to any object we conceive or imagine; and as soon as the conception or imagination is over, the belief which attended it is at an end. We, in fact, consider them as creations of the mind, which have no separate and independent existence, from the facility with which we can recall or dismiss the objects of these powers at pleasure. But when the conceptions of the mind are rendered steady and permanent, by being strongly associated with any sensible impression, as when we gaze on a magnificent prospect, they command our belief no less that our actual perceptions; and, therefore, if it were possible for us, with our eyes shut, to keep up for a length