Page:An Enquiry Concerning Human Understanding - Hume (1748).djvu/252

 nor soft, black nor white, is equally beyond the Reach of human Conception. Let any Man try to conceive a Triangle in general, which is neither Isoceles, nor Scalenum, nor has any particular Length nor Proportion of Sides; and he will soon perceive the Absurdity of all the scholastic Notions with regard to Abstraction and general Ideas.

the first philosophical Objection to the Evidence of Sense or to the Opinion of external Existence consists in this, that such an Opinion, if rested on natural Instinct, is contrary to Reason, and if refer'd to Reason, is contrary to natural Instinct, and at the same time, carries no rational Evidence with it, to convince an impartial Enquirer. The second Objection goes farther, and represents this Opinion as con