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tinct as any two can be; and he that sees not in them a difference of substance, sees it nowhere: to him all natures are one; and that one, an absurd supposition.
15. In favour of what is urged by the phrenologists, it may perhaps be admitted, as a natural law, that, "If a picture of a visible object be formed upon the retina, and the impression be communicated, by the nerves, to the brain, the result will be an act of perception."--_Wayland's Moral Science_, p. 4. But it does not follow, nor did the writer of this sentence believe, that perception is a mere act or attribute of the organized matter of the brain. A material object can only occasion in our sensible organs a corporeal motion, which has not in it the nature of thought or perception; and upon what principle of causation, shall a man believe, in respect to vision, that the thing which he sees, is more properly the cause of the idea conceived of it, than is the light by which he beholds it, or the mind in which that idea is formed? Lord Kames avers, that, "Colour, which appears to the eye as spread upon a substance, has no existence but in the mind of the spectator."--Elements of Criticism, i, 178. And Cicero placed the perception, not only of colour, but of taste, of sound, of smell, and of touch, in the mind, rather than in the senses. "Illud est album, hoc dulce, canorum illud, hoc bene olens, hoc asperum: animo jam hæc tenemus comprehensa, non sensibus."--_Ciceronis Acad._ Lib. ii, 7. Dr. Beattie, however, says: "Colours inhere not in the coloured body, but in the light that falls upon it; * * * and the word colour denotes, an external thing, and never a sensation of the mind."--Moral Science, i, 54. Here is some difference of opinion; but however the thing may be, it does not affect my argument; which is, that to perceive or think is an act or attribute of our immaterial substance or nature, and not to be supposed the effect either of the objects perceived or of our own corporeal organizatio