Abbildungen der Seite
PDF
EPUB

an individual may not even be conscious of the exiftence of this image, that is, experience a fenfation from the agency of it, although his eye still continues to form the image on the retina.

But, fays Mr. Hume, the faint images of thefe impreflions in thinking and reasoning conftitute our ideas. Now, it may be asked, what is meant by the images of found, tafte, fmell, or touch? What is the image of hardness, heat, cold, or any of the qualities and modes of matter? and, as he comprehends under the generic term of impreffions, not only all our external fenfations, but also our paffions and emotions, it may be likewise asked, what can he mean by images of pride, anger, pleafure, or pain? The anfwer is obvious; for no man, from the actual phenomena of his fenfes and paffions, can pretend to a consciousness of these images. Yet it would follow from our author's doctrine, that we can have no ideas without the pre-existence of images, which, in fact, have no existence. Such are the palpable contradictions and abfurdities into which Mr. Hume has fallen, by inconfiderately adopting the notions of his predeceffors, and their inaccurate modes of philofophizing.

The divifion of perceptions into impreffions and ideas, is still farther exceptionable; for a difference in degree is not a difference in quality. When a person touches any thing, he experiences, is confcious of, or has a perception or idea of a certain

feeling,

feeling, and to distinguish its quality or relative degrees, particular words have been contrived. The fenfation he thus experiences may, perhaps, be that which we ftyle hardness; but this fenfation, or, what is the fame, the confcioufnefs of it, may ac tually be mind itself; for we have no good reason to authorize our believing, that the sensation of hardness forms an object distinct from, although present to, the mind. In fine, the identity of per ception, consciousness, and idea, may be fairly maintained; at least, the faculties of the human understanding are incapable of distinguishing them.

The fubfequent illuftrations, which Mr. Hume introduces, are no lefs defective and unphilofophical. From the refemblance, which he discovers between impreffions and ideas in every other particular, except their degree of force and vivacity, he maintains, that the one feem to be, in a manner, the reflection of the other; fo that all the perceptions of the mind are double, and appear both as impreffions and ideas. When," he adds, “I fhut my eyes, and think of my chamber, the ideas I form are exact reprefentations of the impreffions I felt, nor is there any circumftance of the one, which is not to be found in the other."

..

Here he confounds perception and memory, two very different powers of the mind. When he views his chamber with his eyes open, he experiences, not only fenfations, but what in his fyftem

X 3

he

he calls impreffions, which "ftrike with a very lively force upon the mind." Still, however, according to his own doctrine, he has not acquired any ideas; for thefe are only "the faint images of impreffions in thinking and reasoning." It would follow, therefore, that to obtain an exact idea of his chamber, he must contemplate it with his eyes fhut; or would he rather be understood to fignify, that if he kept his eyes open, and thought of his chamber, his mind embraced, at the fame time, both the lively impreffions and their faint images or ideas? A more accurate reafoner would have explained the phenomena in a very different manner. He would have fhewn, that perception, consciousness, and idea in its true philofophical meaning, (and even the term impreffion in Mr. Hume's fenfe of it, for he difclaims the fynonymy of impreffion and fenfation) are the fame, as far as our mental powers are competent to discover; and he would have fhewn, that memory is the faculty which nature employs in preferving, or recalling, ideas or perceptions arifing from the operation of external objects on our fenfes,

Notwithflanding thefe obvious errors, Mr. Hume, in his Effay on the Human Understanding, perfifts in giving the fame divifion of perceptions which he had adopted in his Treatife, as will appear from the following paffage in Section II. the Origin of Ideas."-"We may, therefore," fays he, "divide all the perceptions of the mind into two claffes or fpecies, which are diftinguished

" Of

by

by their different degrees of force and vivacity. The lefs forcible and lively are commonly denomi nated thoughts or ideas. The other species want a name in our language, and in most others; I fuppose, because it was not requifite for any, but philofophical purposes, to rank them under a general term or appellation. Let us, therefore, ufe a little freedom, and call them impreffions; employing that word in a fense fomewhat different from the usual. By the term impression, then, I mean all our more lively perceptions, when we hear, or fee, or feel, or love, or hate, or defire, or will: and impreffions are diftinguished from ideas, which are the lefs lively perceptions of which we are confcious, when we reflect on any of those sensations or movements above-mentioned."

It is, doubtlefs, allowable to every man, who writes a fyftem of fcience or of art, to employ what terms he pleases, provided he gives correct definitions of them in the outfet. But if he employs, in a sense very different from their common acceptation, terms to which mankind have already attached a definite meaning, it is obvious that this practice muft occafion endless confufion. The figns in algebra, and the abstract terms in mathematics, are merely arbitrary; and fo were the words of every original language at its commencement; but their use and purport being once fixed by common confent, the person who ventures to alter or reverse them, will fcarcely merit applause for his ingenuity. Thefe arguments apply still more

[blocks in formation]

forcibly to moral philofophy, where it is not eafy to keep long the mind fteady in any train of thought; a difficulty effentially increased by adopting new and unusual explanations of well known terms.

In the paffage we have quoted, Mr. Hume, aban. doning his theory of images, gives a more ftrict and determinate limitation to the words, impreffion and idea, than he has done in his Treatife. By the former he ieems to mean an idea with the presence of a fenfation, and by the latter an idea without it. Every philofopher must acknowledge, that the idea he has of an external object is more lively and forcible, when the object is prefent to the fenfes, than when it is not. This, however, is merely a difference in degree, and not in quality; and if any writer on metaphyfics fhould chufe to defignate the two cafes by particular terms, he is warranted in doing fo, though not certainly in felecting, as Mr. Hume does, a word to which a fpecific meaning has been already affixed, very different from that in which he would employ it. A fuperficial attention to the phenomena, and a defcription of them in the ordinary phrafeology of the English language, would at once have corrected this error of our author; for he must have remarked, that every external object, by making an impreffion, or acting upon the organs of fenfe, induces a confcioufnefs or idea of the obj&t he beheld: and that our ideas, becoming the objects or agents of thought, are employed in the process of reflection.

As

« ZurückWeiter »