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object which is raised in the mind by the power " of memory." Every thing we have any know
a distance, if things at a distance cannot act upon the mind ? I say more, that it assumes a proposition as true, without evidence, namely, That no distant subject can act upon the mind. This proposition undoubtedly requires evidence, for it is not intuitively certain. And, therefore, till the proposition be demonstrated, every man without scruple may rely upon the conviction of his senses, that he hears and sees things at a distance.
But I venture a bolder step, which is, to show that the proposition is false. Admitting that no being can act but where it is, is there any thing more simple or more common, than the acting upon subjects at a distance by intermediate means ? This holds in fact with respect both to seeing and hearing. When I see a tree, for example, rays of light are reflected from the tree to my eye, forming a picture upon the retina tunica ; but the object perceived is the tree itself, not the rays of light, nor the picture. In this manner distant objects are perceived, without any action of the object upon the mind, or of the mind
the object. Hearing is in a similar case: the air, put in motion by thunder, makes an impression upon the drum of the ear ; but this impression is not what I hear, it is the thunder itself by means of that impression.
With respect to vision in particular, we are profoundly ignorant by what means and in what manner the picture on the retina tunica contributes to produce a sight of the object. One thing only is clear, that as we have no knowledge of that piciture, it is as natural to conceive that it should be made the instrument of discovering the external object, and not itself, as of discovering itself only, and not the external object.
Upon the chimerical consequences drawn from the ideal system, I shall make but a single reflection. Nature determines us necessarily to rely on the veracity of our senses ; and upon their evidence the existence of external objects is to us a matter of intuitive knowledge and absolute certainty. Vain therefore is the attempt of Dr Berkeley, and of his followers, to de
ledge of, whether internal or external, passions, emotions, thinking, resolving, willing, heat, cold, &c. as well as external objects, may be recalled as above, by the power of memory.*
15. External objects are distinguishable into simple and complex. Certain sounds are so simple as not to be resolvable into parts: and so are certain tastes and smells.
Objects of touch are for the most part complex : they are not only hard or soft, but also smooth or rough, hot or cold. Of all external objects, visible objects are commonly the most complex: a tree is composed of a trunk, branches, leaves ; it has colour, figure, size. But as an action is not resolvable into parts, a perception, being an act of sense, is always simple. The colour, figure, umbrage of a spreading oak, raise not different perceptions: the perception is one, that of a tree, coloured, figured, &c. A quality is power of
ceive us, by a metaphysical subtilty, into a disbelief of what we cannot entertain even the slightest doubt.
* From this definition of an idea, the following proposition must be evident, That there can be no such thing as an innate idea. If the original perception of an object be not innate, which is obvious; it is not less obvious, that the idea or secon. dary perception of that object cannot be innate. And yet, to prove this self-evident proposition, Locke has bestowed a whole book of his Treatise upon Human Understanding. So necessary it is to give accurate definitions, and so preventive of dispute are definitions when accurate. Dr Berkeley has taken great pains to prove another proposition equally evident, That there can be no such thing as a general idea : all our original perceptions are of particular objects, and our secondary perceptions or ideas must be equally so.
never perceived separately from the subject; nor a part from the whole. There is a mental abstraction, of which afterward: but the eye never abstracts, nor any other external sense.
16. Many particulars beside those mentioned enter into the perception of visible objects, motion, rest, place, space, time, number, &c. These, all of them, denote simple ideas, and for that reason admit not of a definition. All that can be done, is to point out how they are acquired. The ideas of motion and of rest, are familiar even to a child, from seeing its nurse sometimes walking, sometimes sitting : the former, it is taught to call motion ; the latter, rest. Place enters into every perception of a visible object : the object is perceived to exist, and to exist somewhere, on the right hand or on the left, and where it exists is termed place. Ask a child where its mother is, or in what place : it will answer readily, she is in the garden. Space is connected with size or bulk : every piece of matter occupies room or space in proportion to its bulk. A child perceives that when its little box is filled with playthings, there is no room or space for more. Space is also applied to signify the distance of visible objects from each other; and such space accordingly can be measured. Dinner comes after breakfast, and supper after dinner: a child perceives an interval, and that interval it learns to call time. A child sometimes is alone with its nurse : its mother is sometimes in the room; and sometimes also its brothers and sisters. It perceives a difference be
tween many and few; and that difference it is taught to call number.
17. The primary perception of a visible object is more complete, lively and distinct, than that of any other object. And for that reason, an idea or secondary perception of a visible object, is also more complete, lively, and distinct, than that of any other object. A fine passage in music, may, for a moment, be recalled to the mind with toleraable accuracy; but, after the shortest interval, it becomes no less obscure than the ideas of the other objects mentioned.
18. As the range of an individual is commonly within a narrow space, it rarely happens, that every thing necessary to be known comes under our own perceptions. Language is an admirable contriv, ance for supplying that deficiency; for by language every man's perceptions may be communicated to all: and the same may be done by painting and other imitative arts. The facility of communication depends on the liveliness of the ideas; especially in language, which hitherto has not arrived at greater perfection than to express clear ideas ; hence it is, that poets and orators, who are extremely successful in describing objects of sight, find objects of the other senses too faint and obscure for language. An idea thus acquired of an object at second hand, ought to be distinguished from an idea of memory, though their resemblance has occasioned the same term idea to be applied to both ; which is to be regretted, because ambiguity in the signification of words is a great obstruction
to accuracy of conception. Thus nature hath furnished the means of multiplying ideas without end, and of providing every individual with a sufficient stock to answer, not only the necessities, but even the elegancies of life.
19. Further, man is endued with a sort of creative power : he can fabricate images of things that have no existence. The materials employed in this operation, are ideas of sight, which he can take to pieces and combine into new forms at pleasure : their complexity and vivacity make them fit materials : But a man hath no such power over any of his other ideas, whether of the external or internal senses : he cannot, after the utmost effort, combine these into new forms, being too obscure for that operation. An image thus fabricated cannot be called a secondary perception, not being derived from an original perception : the poverty of language, however, as in the case immediately above mentioned, has occasioned the same term idea to be applied to all. This singular power of fabricating images without any foundation in reality, is distinguished by the name imagination.
20. As ideas are the chief materials employed in reasoning and reflecting, it is of consequence that their nature and differences be understood. It
appears now, that ideas may be distinguished into three kinds : first, Ideas derived from original perceptions, properly termed ideas of memory ; second, Ideas communicated by language or other signs ; and, third, Ideas of imagination. These ideas differ from each other in many respects ; but chiefly in