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difference but that it is lefs diftinct than formerly.* This
*This experiment, which every one may reiterate till entire fatisfaction be obtained, is of greater importance than at first view may appear; for it ftrikes at the root of a celebrated doctrine,. which for more than two thousand years has mifled many philofophers. This doctrine as delived by Ariftotle is in fubftance, That of every object of thought there must be in the mind fome form, phantafm, or fpecies; that things fenfible are perceived and remembered by means of fenfible phantafms, and things intelligible by intelligible phantafms; and that these phan talms have the form of the object without the matter, as the impreffion of a feal upon wax has the form of a feal without its matter." The followers of Ariftotle add," That the fenfible and intelligible forms of things, are fent forth from the things themfelves, and make impreffions upon the paffive intellect, which impreffions are perceived by the active intellect. This notion differs very little from that of Epicurus, which is, "That all things fend forth conftantly and in every direction, flender ghofs or films of themfelves. (tenuia fimulatra, as expreffed by his commentator Lucretius ;) which ftriking upon the mind, are the means, of perception, dreaming," &c. Des Cartes, bent to oppofe Ariftotle, rejects the doctrine of fenfible and intelligible phantafms; maintaining however the fame doctrine in effect, namely, That we perceive nothing external but by means of fome image either in the brain or in the mind: and thefe images he terms ideas. According to thefe philofophers, we perceive nothing immediately but phantafms or ideas; and from these we infer, by reafoning, the exiftence of external objects. Locke, adopting this doctrine, employs almoft 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 reafonirg upon their ideas or images in the mind; taking it for granted, that we are confcious of thefe ideas or images; and of nothing elfe. Thofe who talk the moft intelligibly explain the doctrine thus: When I fee in a mirror a man flanding behind me, the immediatc object of my fight is his image, without which I could not fee him : in like manner, when I fee a tree or a houfe, there must be an image of thefe objects in my brain or in my mind; which image is the immediate object of my perception; and by means of that image I perceive the external object.
One would not readily fufpect any harm in this ideal fyflem, other than the leading us into a labyrinth of metaphilical errors, in order. to account for our knowledge of external objects, which is more truly and more fimply accounted for by direct perception. And yet some late writers have been able to extract from it death and deflruction to the whole world, levelling all down to a mere chaos of ideas. Dr. Berkeley, upon authority of the philofophers named, taking for granted, that we cannot perceive any object but what is in the mind, difcovered, that the reafoning employed by Des Cartes and Locke to infer the exifience of external objects, is inconclufive; and upon that difcovery ventured, against common fenfe, to annihilate totally the material world.. And a
This indiftinct fecondary perception of an object, is termed an idea. And therefore the precife and ac
later writer, difcovering that Berkeley's arguments might with equal fuccefs be applied againft immaterial beings, ventures ftill 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 fingle mind for fhelter or support.
When fuch wild and extravagant confequences can be drawn from the ideal fyftem, it might have been expected, that no man who is not crazy would have ventured to erect fuch a fuperftructure, till he fhould firft be certain beyond all doubt of a folid foundation. And yet upon inquiry, we find the foundation of this terrible doctrine to be no better than a fhallow metaphyfical argument, namely, "That no being can act but where it is; and, confequently, that it cannot act upon any fubject at a diftance." This argument poffeffes indeed one eminent advantage, that its obfcurity, like that of an oracle, is apt to impofe upon the reader, who is willing to confider it as a demonftration, because he does not clearly fee the fallacy. The beft way to give it a fair trial, is to draw it out of its obfcurity, and to flate it in a clear light, as follows. "No fubje&t can be perceived unless it act upon the mind, but no diftant fubject can act upon the mind, becaufe no being can act but where it is: and, therefore, the immediate object of perception must be fomething united to the mind fo as to be able to act upon it." Here the argument is completed in all its parts; and from it is derived the fuppofed neceffity of phantafms or ideas united to the mind, as the only objects of perception. It is fingularly unlucky, that this argument concludes directly againfl the very fyftem of which it is the only foundation; for how can phantafms or ideas be raised in the mind by things at a diflance, if things at a diftance cannot act upon the mind? I fay more, that it affumes a propofition as true, without evidence, namely, That no distant subject can act upon the mind. This propofition undoubtedly requires evidence, for it is not intuitively certain. And, therefore, till the propofition be demonftrated, every man without fcruple may rely upon the conviction of his fenfes, that he hears and fees things at a diftance.
But I venture a bolder ftep, which is, to show that the propofition is falfe. Admitting that no being can act but where it is, is there any thing more fimple or more common, than the acting upon fubjects at a distance by intermediate means? This holds in fact with refpect both to feeing and hearing. When I fee 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 itfelf, not the rays of light, nor the picture. In this manner diftant objects are perceived, without any action of the object upon the mind, or of the mind upon the object. Hearing is in a fimilar cafe: the ear, put in motion by thunder, makes an impreffion upon the drum of the ear; but this impreffion is not what I hear, it is the thunder itfelf by means of that impreffion.
With refpect to vifion in particular, we are profoundly ignorant by what means and in what manner the picture on the retina tunica contrib utes to produce a fight 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
turate definition of an idea in contradiftinction to an original perception, is, "That 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, paffions, emotions, thinking, refolving, willing, heat, cold, &c. as well as external objects, may be recalled as above, by the power of memory.*
15. External objects are diftinguishable into fimple and complex. Certain founds are fo fimple as not to be refolvable into parts; and fo are certain tastes and smells. Objects of touch are for the most part complex: they are not only hard or foft, but also smooth or rough, hot or cold. Of all external objects, visible objects are commonly the moft complex a tree is compofed of a trunk, branches, leaves it has colour, figure, fize. But as an action is not refolvable into parts, a perception being an act of fenfe, is always fimple. The colour, figure, umbrage of a spreading oak, raife not different perceptions: the perception is one, that of a tree, coloured,
fhould be made the inftrument of difcovering the external object, and nor itself, as of difcovering itfelf only, and not the external object.
Upon the chimerical confequences drawn from the ideal fyftem, I fhall make but a fingle reflection. Nature determines us neceffarily to rely on the veracity of our fenfes; and upon their evidence the exiflence of external objects is to us a matter of intuitive knowledge and abfolute cer tainty. Vain therefore is the attempt of Dr. Berkeley and of his fol lowers, to deceive us, by a metaphyfical fubtility, into a difbelief of what we cannot entertain even the flightest doubt.
* From this definition of an idea, the following propofition must be evident, That there can be no fuch thing as an innate idea. If the orig inal perception of an object be not innate, which is obvious; it is not Jefs obvious, that the idea or fecondary perception of that object cannot be innate. And yet to prove this felf-evident propofition, Locke has bestowed a whole book of his Treatife upon Human Understanding. So neceffary it is to give accurate definitions, and fo preventive of difpute are definitions when accurate. Dr. Berkeley has taken great pains to prove another propofition equally evident, that there can be no fuch thing as a general idea: all our original perceptions are of particular objetts, and our fecondary perceptions or ideas mufl be equally fo.
oured, figured, &c. A quality is never perceived fep arately from the fubject; nor a part from the whole. There is a mental power of abftraction, of which af terward; but the eye never abftracts, nor any other external fenfe.
16. Many particulars befide thofe mentioned enter into the perception of visible objects, motion, reft, place, space, time, number, &c. Thefe, all of them denote fimple ideas, and for that reafon admit not of a definition. All that can be done, is to point out how they are acquired. The ideas of motion and of reft, are familiar even to a child, from feeing its nurfe fometimes walking, fometimes fitting: the former it is taught to call motion; the latter, reft. Place enters into every perception of a visible object: the object is perceived to exift, and to exift fomewhere, on the right hand or on the left, and where it exifts is termed place. Afk a child where its mother is, or in what place it will answer readily, fhe is in the garden. Space is connected with fize 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 fpace for more. Space is alfo applied to fignify the diftance of vifible objects from each other; and fuch space accordingly can be measured. Dinner comes after breakfaft, and fupper after dinner: a child perceives an interval, and that interval it learns to call time. A child fometimes is alone with its nurfe: its mother is fometimes in the room; and fometimes alfo its brother and fifters. It perceives a difference between many and few; and that difference it is taught to call number.
17. The primary perception of a vifible object, is more complete, lively and diftin&t, than that of any other object. And for that reafon an idea or fecondary perception of a visible object, is alfo more complete, lively, and diftinct, than that of any other ob
fect. A fine paffage in mufic, may, for a moment, be recalled to the mind with tolerable accuracy; but after the shortest interval, it becomes no lefs obfcure 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 .neceffary to be known comes under our own perceptions. Language is an admirable contrivance for fupplying that deficiency; for by language every man's perceptions may be communicated to all: and the fame may be done by painting and other imitative arts. The facility of communication depends on the liveliness of the ideas; efpecially in language, which hitherto has not arrived at greater perfection than to exprefs clear ideas: hence it is, that poets and orators, who are extremely fuccefsful in defcribing objects of fight, find objects of the other fenfes too faint and obfcure for language. An idea thus acquired of an object at fecond hand, ought to be diftinguished from an idea of memory, though their refemblance has occafioned the fame term idea to be applied to both; which is to be regretted, because ambiguity in the fignification of words is a great ob→ ftruction to accuracy of conception. Thus Nature hath furnished the means of multiplying ideas without end, and of providing every individual with a fufficient ftock to anfwer, not only the neceffities, but even the elegancies of life.
19. Further, man is-endued with a fort of creative power: he can fabricate images of things that have no existence. The materials employed in this operation, are ideas of fight, which he can take to pieces and combine into new forms at pleafure; their complexity and vivacity make them fit materials: But a man hath no fuch power over any of his other ideas, whether of the external or internal fenfes: he cannot, after the utmost effort, combine these into new forms, being too obfcure for that operation. An im