Sidebilder
PDF
ePub

perception, he had erected an impregnable fortress, at a point too in which there was previously no adequate defence against the scepticism of Berkeley, and Hume; but I apprehend in this expectation he was entirely mistaken. Since all you know about an external world, exclaim, Berke. ley and Hume, consists of your sensations, how can you conclude that there is any thing existing distinct from your sensations? We have shown how other philosophers resolved this query. Dr. Reid, would reply; because, besides my sensations of the qualities of bodies, I have distinct perceptions of those qualities, and my perceptions must always have an external object. The reply might be made still by the scepticks, how do you know that there exists in the world any thing more than your perceptions and sensations, admitting that they are distinct acts of the mind? Your perceptions are in the mind, as well as your sensations, and morenver you yourself admit, that it is by means of sensations you arrive at your perceptions of the qualities of bodies. Now, under these circumstances, can you derive from these perceptions any better proof of the existence of external objects than from your sensations? You yourself admit in the case of the rose, “ the object of my perception in this case is that quality in the rose, which I discern by the sense of smell.” Now can this act of perception, which depends upon sensation for all the information it obtains about the qualities of body, give you a more complete knowledge of the external world, than sensation itself?

It is, I think sufficiently apparent from the foregoing observations, that Dr. Reid has erected no new or more effectual barriers, than had been reared by his predecessors, against the inroads of sophistry, and scepticism. Berkeley, and Hume, if they were now living, might maintain their doctrines with as much plausibility as ever, and find no greater impediments than formerly, in raising their superstructure. The fact is, that a belief in the existence of bodies and their

нь

qualities necessarily accompanies our perceptions, as a be. lief in things, which we distinctly remember having once existed, accompanies the remembrance of them, or as the belief that a proposition is actually presented to our understandings attends our attempts to comprehend it, or as the belief that the sword which has wounded us exists, from the circumstance of its having inflicted the wound.

CHAPTER VII.

Of the Primary and Secondary qualities of Bodies.

The primary qualities of body, as enumerated by Mr. Locke, are extension, figure, solidity, motion, rest, hardness, softness, divisibility, fluidity; the secondary, are sound, colour, taste, smell, heat and cold, and such like. The first are called primary, because they inseparably belong to matter in whatever state or condition it be found, and whatever may be the modifications and alterations it may undergo: the second, secondary, because they are in the bodies them selves only the powers to produce certain sensations in us, and these powers appear to be the result of the primary qualities, as the bulk, figure and texture, of the several objects of sense: This distinction between the primary and secondary qualities of body, which seems to have been unnoticed by Aristotle, was first adyerted to by Des Cartes, and afterwards more clearly stated by Mr. Locke.

There appears to be a real foundation in nature for this distinction. And what is worthy of remark on this point, is, that in the structure of language, which is not framed generally with a view to philosophical disquisition, but for the purpose of ordinary intercourse; in the case of primary qualities, the names are given to those qualities as they exist in their subject, without any reference to our perceptions; and in the case of the secondary a procedure directly the reverse is to be observed, for here names are assigned to our sensations, without any reference to the qualities of body, or to the causes of our sensations, as Aristotle would say. Colour, taste, sound, smell, heat, cold are obviously mere sensations in our minds produced by the action of outward objects upon the senses; while extension, figure motion, &c. have no kind of dependance upon our perceptions. The vulgar, however, who do not find it necessary, in the daily transactions of life, nicely to discriminate, soon transfer the names of their perceptions to those powers or qualities in bodies that excite them. Hence heat is said to be in the fire, coldness in ice, sugar is said to be sweet, and wormwood bitter; when it is evident that heat, cold, sweetness, bitterness are not qualities in bodies, but merely sensations in us.

The controversy, therefore, between the philosopher and the vulgar, when the one strenuously contends that there is no heat in fire, coldness in snow, sweetness in sugar, or bitterness in wormwood, and the other as strenu. ously contends that there are, is idle and frivolous, as it turns merely upon the meaning of a word; as for instance, whether the terms heat, cold, sweetness, bitterness, denote our sensations, or the qualities of bodies that occasion them. When the philosopher maintains, that there is no heat in fire, he means that the sensation of heat is not in that element, which everyone will admit; when the vulgar declare that there is heat in fire, they mean that the quality is in fire which excites heat in us, which is equally indisputable. Thus the whole mystery is solved; the vulgar freed from maintaining an absurdity; and philosophy relieved from the charge of a fondness for paradox, and a disregard to the dictates of com

mon sense.

Such are the doctrines of the schools in regard to the primary and secondary qualities of body. The only slight inaccuracy, to which I before adverted, with which the doctrine of Mr. Locke on this point appears to be justly chargeable, is that of admitting a resemblance between our ideas and the primary qualities of body; into which error he must have been betrayed, in the first place, from the extreme distinctness of our ideas of the primary qualities compared with the secondary; and in the second place, from an unwillingness to depart too far from the dogmas of the school philosophy, which allowed a similitude in all cases whatever. Amidst the studied efforts of Bishop Berkeley to darken counsel in metaphysical science, and to blind the eyes of his readers, by raising a cloud of refinement and sophistry, he had the merit of detecting this inaccuracy in Mr. Locke, although he endeavours to pervert it to the purpose of scepticism. This observation has been made by Dr. Reid, and had that writer, after stating at full length the precise doctrines of Mr. Locke, been contented with setting him right in this particular, and bestowing the praise of detecting the error upon him who merited it, he would never have met with any remonstrance or animadversion from me relative to this matter. But can the most enlarged charity fail to discern in the following criticisms, a studied and reprehensible attempt to decry the merits and disparage the productions of Mr. Locke? “Let us hear, now,” says the Dr. “how Mr, Locke explains the nature of those ideas, when applied to primary and secondary qualities. Book 2, ch. 8, sect. 7.“ To discover the nature of our ideas the better, and to discourse of them intelligibly, it will be convenient to distinguish them, as they are ideas or perceptions in our minds, and as they are modifications of matter in the bodies that cause such percep. tions in us; that so we may not think, (as perhaps usually is done) that they are exactly the images and resemblances of something inherent in the subject; most of those of sensation being in the mind no more the likeness of something existing without us, than the names that stand for them, are the likeness of our ideas, which, yet upon hearing they are apt to excite in us." Upon this passage of Mr. Locke, Dr. Reid, makes the following observations. “ This way of dis

« ForrigeFortsett »