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our passions and emotions, and for all our other pleasures and pains.

13. That we cannot perceive an external object till an impression is made upon our body, is probable from reason, and is ascertained by experience. But it is not necessary that we be made sensible of the impression in touching, in tasting, and in smelling, we are sensible of the impression; but not in seeing and hearing. We know indeed from experiments, that before we perceive a visible object, its image is spread upon the retina tunica; and that before we perceive a sound, an impression is made upon the drum of the ear: but we are not conscious either of the organic image or of the organic impression; nor are we conscious of any other operation preparatory to the act of perception : all we can say, is, that we see that river, or hear that trumpet.*

14. Objects once perceived may be recalled to the mind by the power of memory. When I recal an object of sight in that manner, it appears to me precisely the same as in the original survey, only less distinct. For example, having seen yesterday a spreading oak growing on the brink of a river, I endeavour to recal these objects to my mind. How is this operation performed? Do I endeavour to form in my mind a picture of them or representative image? Not so.. I transport myself ideally to the place where I saw the tree and river yesterday; upon which I have a perception

* Yet a singular opinion that impressions are the only objects of perception, has been espoused by some philosophers of no mean rank; not attending to the foregoing peculiarity in the senses of seeing and hearing, that we perceive objects without being conscious of an organic impression, or of any impression. See the Treatise upon Human Nature: where we find the following passage, book I. p. iv. sect. 2. "Properly speaking, it is not our body we perceive when we regard our limbs and members; so that the ascribing a real and "corporeal existence to these impressions, or to their objects, is an "act of the mind as difficult to explain," &c.

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of these objects, similar in all respects to the perception I had when I viewed them with my eyes, only less distinct. And in this recollection, I am not conscious of a picture or representative image, more than in the original survey; the perception is of the tree and river themselves, as at first. I confirm this by another experiment. After attentively surveying a fine statue, I close my eyes. What follows? The same object continues, without any difference but that it is less distinct than formerly. This indistinct secondary perception

This experiment, which every one may reiterate till entire satisfaction be obtained, is of greater importance than at first view may appear; for it strikes at the root of a celebrated doctrine, which for more than two thousand years has misled, many philosophers. This doctrine as delivered by Aristotle is in substance, "That of every "object of thought there must be in the mind some form, phantasm, "or species; that things sensible are perceived and remembered by "means of sensible phantasms, and things intelligible by intelligi"ble phantasms; and that these phantasms have the form of the ob"ject without the matter, as the impression of a seal upon wax has "the form of a seal without its matter." The followers of Aristotle add, "That the sensible and intelligible forms of things, are sent "forth from the things themselves, and make impressions upon the "passive intellect, which impressions are perceived by the active in"tellect." This notion differs very little from that of Epicurus, which is, “That all things send forth constantly and in every direc ❝tion, slender ghosts, or films of themselves, (tenuia simulacra, as "expressed by his commentator Lucretius); which striking upon "the mind, are the means of perception, dreaming," &c. Des Cartes, bent to oppose Aristotle, rejects the doctrine of sensible and intelligible phantasms; maintaining however the same doctrine in effect, namely, That we perceive nothing external but by means of some image either in the brain or in the mind: and these images he terms ideas. According to these philosophers, we perceive nothing immediately but phantasms or ideas: and from these we infer, by reasoning, the existence of external objects. Locke, adopting this doctrine, employs almost the whole of his book about ideas. He holds, that we cannot perceive, remember, nor imagine, any thing, but by having an idea or image of it in the mind. He agrees with Des Cartes, that we can have no knowledge of things external, but what we acquire by reasoning upon their ideas or images in the mind; taking it for granted, that we are conscious of these ideas or images, and of nothing else. Those who talk the most intelligibly explain the doctrine thus: When I see in a mirror a man standing behind me, the immediate object of my sight is his image, without which I could not see him: in like manner, when I see a tree or a house, there must be an image of these objects in my brain or in my mind;

of an object, is termed an idea. And therefore the precise and accurate definition of an idea in contradistinction to an original perception, is, "That

which image is the immediate object of my perception; and by means of that image I perceive the external object.

One would not readily suspect any harm in this ideal system, other than the leading us into a labyrinth of metaphysical errors, in order to account for our knowledge of external objects, which is more truly and more simply accounted for by direct perception. And yet some late writers have been able to extract from it death and destruction to the whole world, levelling all down to a mere chaos of ideas. Dr. Berkeley, upon authority of the philosophers named, taking for granted that we cannot perceive any object but what is in the mind, discovered, that the reasoning employed by Des Cartes and Locke to infer the existence of external objects, is inconclusive; and upon that discovery ventured, against common sense, to annihilate totally the material world. And a later writer, discovering that Berkeley's arguments might with equal success be applied against immaterial beings, ventures still more boldly to reject by the lump the immaterial world as well as the material; leaving nothing in nature but images or ideas floating in vacuo, without affording them a single mind for shelter or support.

When such wild and extravagant consequences can be drawn from the ideal system, it might have been expected, that no man who is not crazy would have ventured to erect such a superstructure, till he should first be certain beyond all doubt of a solid foundation. And yet upon inquiry, we find the foundation of this terrible doctrine to be no better than a shallow metaphysical argument, namely, "That "no being can act but where it is; and, consequently, that it cannot "act upon any subject at a distance." This argument possesses indeed one eminent advantage, that its obscurity, like that of an oracle, is apt to impose upon the reader, who is willing to consider it as a demonstration, because he does not clearly see the fallacy. The best way to give it a fair trial, is to draw it out of its obscurity, and to state it in a clear light, as follows. "No subject can be perceived un"less it act upon the mind, but no distant subject can act upon the "mind, because no being can act but where it is: and, therefore, "the immediate object of perception must be something united to "the mind, so as to be able to act upon it." Here the argument is completed in all its parts; and from it is derived the supposed necessity of phantasms or ideas united to the mind, as the only objects of perception. It is singularly unlucky, that this argument concludes directly against the very system of which it is the only foundation; for how can phantasms or ideas be raised in the mind by things at 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

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perception of a real object which is raised in the mind by the power of memory." Every thing we have any knowledge 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

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 upon 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 picture, 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 deceive 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 secondary perception of that ob ject 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.

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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 never perceived separately from the subject; nor a part from the whole. There is a mental power of 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 dis tance of visible objects from each other; and such space accordingly can be measured. Dinner comes after breakfast, and supper after dinner: a child

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