41. _Secondly_, it will be objected that there is a great difference betwixt real fire for instance, and the idea of fire, betwixt dreaming or imagining oneself burnt, and actually being so. [(602)If you suspect it to be only the idea of fire which you see, do but put your hand into it and you will be convinced with a witness.] This and the like may be urged in opposition to our tenets.—To all which the answer is evident from what hath been already said(603); and I shall only add in this place, that if real fire be very different from the idea of fire, so also is the real pain that it occasions very different from the idea of the same pain, and yet nobody will pretend that real pain either is, or can possibly be, in an unperceiving thing, or without the mind, any more than its idea(604). ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ 42. _Thirdly_, it will be objected that we see things actually without or at a distance from us, and which consequently do not exist in the mind; it being absurd that those things which are seen at the distance of several miles should be as near to us as our own thoughts(605).—In answer to this, I desire it may be considered that in a dream we do oft perceive things as existing at a great distance off, and yet for all that, those things are acknowledged to have their existence only in the mind. 43. But, for the fuller clearing of this point, it may be worth while to consider how it is that we perceive distance, and things placed at a distance, by sight. For, that we should in truth _see_ external space, and bodies actually existing in it, some nearer, others farther off, seems to carry with it some opposition to what hath been said of their existing nowhere without the mind. The consideration of this difficulty it was that gave birth to my _Essay towards a New Theory of Vision_, which was published not long since(606). Wherein it is shewn that distance or outness is neither immediately of itself perceived by sight(607), nor yet apprehended or judged of by lines and angles, or anything that hath a necessary connexion with it(608); but that it is only suggested to our thoughts by certain visible ideas, and sensations attending vision, which in their own nature have no manner of similitude or relation either with distance or things placed at a distance(609); but, by a connexion taught us by experience, they come to signify and suggest them to us, after the same manner that words of any language suggest the ideas they are made to stand for(610). Insomuch that a man born blind, and afterwards made to see, would not, at first sight, think the things he saw to be without his mind, or at any distance from him. See sect. 41 of the forementioned treatise.