The peculiarity in the case of visible objects, feems to arise from this; that when we think of a found or of a taste, the object of our conception is one fingle detached fenfation; whereas every visible object is complex; and the conception which we form of it as a whole, is aided by the affociation of ideas. To perceive the force of this obfervation, it is neceffary to recollect what was formerly faid on the subject of attention. As we cannot at one inftant attend to every point of the picture of an object on the retina, fo, I apprehend, we cannot at one inftant form a conception of the whole of any vifible object; but that our conception of the object as a whole, is the refult of many conceptions. The affociation of ideas connects the different parts together, and prefents them to the mind in their proper arrangement; and the various relations which these parts bear to one another in point of fituation, contribute greatly to strengthen the affociations. It is some confirmation of this theory, that it is more easy to remember a fucceffion of founds, than any particular found which we have heard detached and unconnected.

The power of conceiving visible objects, like all other powers that depend on the affociation of ideas, may be wonderfully improved by habit. A perfon accustomed to drawing, retains a much more perfec 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 form of the human body from memory, with as little exertion of attention, as he employs in writing the letters which compose his name.

In the power of conceiving colours, too, there are ftriking differences among individuals: and, indeed, I am inclined to fufpect, that, in the greater number of inftances, the fuppofed defects of fight in this respect, ought to be afcribed rather to a defect in the power of conception. One thing is certain, that we often see men who are perfectly fenfible of the dif ference between two colours when they are presented to them, who cannot give names to these colours, with confidence, when they fee them apart; and are perhaps apt to confound the one with the other. Such men, it fhould feem, feel the fenfation of colour like other men, when the object is prefent, but are incapable (probably in confequence of fome early habit of inattention) to conceive the fenfation diftinctly when the object is removed. Without this power of conception, it is evidently impoffible for them, how ever lively their fenfations may be, to give a name to any colour; for the application of the name fuppofes not only a capacity of receiving the fenfation, but a power of comparing it with one formerly felt. the fame time, I would not be understood by these obfervations to deny, that there are cafes, in which there is a natural defect of the organ in the perception of colour. In fome cafes, perhaps, the fensation is not felt at all; and in others, the faintness of the fenfation may be one cause of those habits of inattention, from which the incapacity of conception

has arisen.

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A talent for lively defcription, at least in the cafe. of fenfible objects, depends chiefly on the degree in which the defcriber poffeffes the power of conception.

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We may remark, even in common converfation, a striking difference among individuals in this respect. One man, in attempting to convey a notion of any object he has seen, feems to place it before him, and to paint from actual perception: another, although not deficient in a ready elocution, finds himself in fuch a fituation confufed and embarraffed among a number of particulars imperfectly apprehended, which crowd into his mind without any just order and connection. Nor is it merely to the accuracy of our defcriptions that this power is fubfervient: it contributes more than any thing elfe to render them ftriking and expreffive to others, by guiding us to a felection of fuch circumstances as are most prominent and characteristical; infomuch that I think it may reasonably be doubted, if a perfon would not write a happier description of an object from the conception than from the actual perception of it. It has been often remarked, that the perfection of defcription does not confift in a minute fpecification of circumstances, but in a judicious felection of them; and that the best rule for making the selection is, to attend to the particulars that make the deepest impreffion on our own minds. When the object is actually before us, it is extremely difficult to compare the impreffions which different circumftances produce; and the very thought of writing a description, would prevent the impreffions which would otherwife take place. When we afterwards conceive the object, the reprefentation of it we form to ourselves, however lively, is merely an outline; and is made up of those circumstances, which really ftruck us most at the moment; while others of

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lefs importance are obliterated. The impreffion, indeed, which a circumstance makes on the mind, will vary confiderably with the degree of a perfon's tafte; but I am inclined to think, that a man of lively conceptions, who paints from these, while his mind is yet warm from the original scene, can hardly fail to fucceed in descriptive compofition.

The facts and obfervations which I have now mentioned, are applicable to conception, as diftinguished from imagination. The two powers, however, are very nearly allied; and are frequently fo blended, that it is difficult to fay, to which of the two, fome particular operations of the mind are to be referred. There are alfo many general facts which hold equally with respect to both. The observations which follow, if they are well founded, are of this number, and might have been introduced with equal propriety under either article. I mention them here, as I fhall have occafion to refer to them in the course of the following work, in treating of fome fubjects, which will naturally occur to our examination, before we have another opportunity of confidering this part of our conftitution.

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It is a common, I believe I may fay an univerfal, doctrine among logicians, that conception (or imagination, which is often used as fynonymous with it) is attended with no belief of the existence of its object. Perception," fays Dr. Reid," is attended with a "belief of the prefent exiftence of its object; memory, with a belief of its past existence; but imagi"nation is attended with no belief at all; and was "therefore called by the school-men, apprchenfio fim

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It is with great diffidence, that I presume to call in question a principle, which has been fo generally received; yet there are several circumstances which lead me to doubt of it. If it were a specifical distinction between perception and imagination, that the former is always attended with belief, and the latter with none; then the more lively our imagination were of any object, and the more completely that object occupied the attention, the less would we be apt to believe its existence; for it is reasonable to think, that when any of our powers is employed feparately from the reft, and there is nothing to withdraw the attention from it, the laws which regulate its operation will be most obvious to our obfervation, and will be most completely difcriminated from those which are characteristical of the other powers of the mind. So very different however is the fact, that it is matter of common remark, that when imagination is very lively, we are apt to describe to its objects a real existence, as in the case of dreaming or of madness; and we may add, in the case of those who, in spite of their own general belief of the abfurdity of the vulgar stories of apparitions, dare not truft themselves alone with their own imaginations in the dark. That imagination is in these inftances attended with belief, we have all the evidence that the nature of the thing admits of; for we feel an act in the fame manner as we should do, if we believe that the objects of our attention were real; which is the only proof that metaphysicians produce, or can produce, of the belief which accompanies perception.