92. It is in this inquiry that he reaches that important distinction between the primary and secondary properties of matter, the latter being modifications of the former, relative only to our apprehension, but not inherent in things, which, without being wholly new, contradicted the Aristotelian theories of the schools;[232] and he remarked that we are never, strictly speaking, deceived by our senses, but by the inferences which we draw from them. [232] See Stewart’s First Dissertation on the Progress of Philosophy. This writer has justly observed, that many persons conceive _colour_ to be inherent in the object, so that the censure of Reid on Descartes and his followers, as having pretended to discover what no one doubted, is at least unreasonable in this respect. A late writer has gone so far as to say: “Nothing at first can seem a more rational, obvious, and incontrovertible conclusion, than that the colour of a body is an inherent quality, like its weight, hardness, &c; and that to _see_ the object, and to see it of _its own colour_, when nothing intervenes between our eyes and it, are one and the same thing. Yet this is only a prejudice.” &c. Herschel’s Discourse on Nat. Philos., p. 82. I almost even suspect that the notion of sounds and smells being secondary or merely sensible qualities, is not distinct in all men’s minds. But after we are become familiar with correct ideas, it is not easy to revive prejudices in our imagination. In the same page of Stewart’s Dissertation, he has been led, by dislike of the university of Oxford, to misconceive, in an extraordinary manner, a passage of Addison in the Guardian, which is evidently a sportive ridicule of the Cartesian theory, and is absolutely inapplicable to the Aristotelian. 93. Such is nearly the substance, exclusive of a great variety of more or less episodical theories, of the three metaphysical works of Descartes, the history of the soul’s progress from opinion to doubt, and from doubt to certainty. Few would dispute, at the present day, that he has destroyed too much of his foundations to render his superstructure stable; and to readers averse from metaphysical reflection, he must seem little else than an idle theorist, weaving cobwebs for pastime which common sense sweeps away. It is fair, however, to observe, that no one was more careful than Descartes to guard against any practical scepticism in the affairs of life. He even goes so far as to maintain, that a man having adopted any practical opinion on such grounds as seem probable should pursue it with as much steadiness as if it were founded on demonstration; observing, however, as a general rule, to choose the most moderate opinions among those which he should find current in his own country.[233] [233] Vol. i., p. 147. Vol. iii., p. 64. |Objections made to his Meditations.|