stance to fome part of my body. This belief as certainly accompanies the fenfation, as the fenfation accompanies the application of the stone to my organ of sense. I believe, with as much affurance, and as unavoidably, that the external thing exists, and is hard, as I believe that I receive, and am confcious of, the fenfation of hardnefs, or, to speak more strictly, the fenfation which by experience I know to be the fign of my touching a hard body *. Now, why do I believe that this fenfation is a real fenfation, and really felt by me? Becaufe my conftitution is fuch that I must believe fo. And why do I believe, in confequence of my receiving this fenfation, that I touch an external object, really exifting, material, and hard? The answer is the fame the matter is incapable of proof: I believe, because I must believe. Can I avoid believing, that I really am confcious of receiving this fenfation? No, certainly. Can I avoid believing, that the external thing exifts, and has a certain quality, which fits it, on being applied to my hand, to excite a certain feeling or *See Dr Reid's Inquiry into the human mind, chap. 5. Lect. 3. fenfation fenfation in my mind? No; I must believe this, whether I will or not. Nor could I diveft myself of this belief, though my life and future happiness depended on the confequence. To believe our fenfes, is, therefore, according to the law of our nature; and we are prompted to this belief, not by reason, but by instinct, or common fenfe. I am as certain, that at present I am in a house, and not in the open air; that I fee by the light of the fun, and not by the light of a candle; that I feel the ground hard under my feet; and that I lean against a real material table,---- as I can be of the truth of any geometrical axiom, or of any demonftrated conclufion; nay, I am as certain of all this as I am of my own existence. But I cannot prove by argument, that there is fuch a thing as matter in the world, or even that I myfelf exift: and yet I know as affuredly, that I do exift, and that there is a real material fun, and a real material world, with moun tains, trees, houfes, and animals, existing feparately, and independently on me and my faculties; I fay, I know all this with as much affurance of conviction, as the moft irrefragable demonftration could produce. duce. Is it unreasonable to believe in these cafes without proof? Then, I affirm, it is equally unreasonable to believe in any cafe with proof. Our belief in either cafe is unavoidable, and according to the law of our nature; and if it be unreasonable to think according to the law of our nature, it is equally unreasonable to adhere to the earth, to be nourished with food, or to die when the head is feparated from the body. It is indeed eafy to affirm any thing, provided a man can reconcile himfelf to hypocrify and falfehood. A man may affirm, that he fees with the foles of his feet, that he believes there is no ma terial world, that he difbelieves his own existence. He may as well fay, that he believes one and two to be equal to fix, a part to be greater than a whole, a circle to be a triangle, and that it is poffible for the fame thing, at the fame time, to be and not to be. But it is faid, that our fenfes do often impofe upon us, and that by means of reafon we are enabled to detect the impofture, and to judge rightly even where our fenfes give us wrong information; that therefore our belief in the evidence of fenfe fense is not instinctive or intuitive, but fuch as may be either confuted or confirmed by reasoning. We fhall acknowledge, that our fenfes do often impofe upon us : but a little attention will convince us, that reason, though it may be employed in correcting the prefent fallacious fenfation, by referring it to a former fenfation, received by us, or by other men, is not the ultimate judge in this matter; for that all fuch reasoning is refolvible into this principle of common fenfe, That things are what our external fenfes represent them. One instance will be fufficient for illuftra tion of this point. After having looked a moment at the fun, I fee a black, or perhaps a luminous, circle fwimming in the air, apparently at the distance of two or three feet from my eyes. That I fee fuch a circle, is certain; that I believe I see it, is certain; that I be→ lieve its appearance to be owing to fome caufe, is alfo certain: thus far there can be no imposture, and there is no fuppofi tion of any, Suppofe from this appearance I conclude, that a real, folid, tangible or visible, round substance, of a black or yellow colour, is actually fwimming in the the air before me; in this I fhould be mif- organ |