_B._ You know the rubbing or hard pressing of the eye, or a stroke upon it, makes an apparition of light without and before it, which way soever you look. This can proceed from nothing else but from the restitution of the organ pressed or stricken, unto its former ordinary situation of parts. Does not the sun by his thrusting back the air upon your eyes press them? Or do not those bodies whereon the sun shines, though by reflection, do the same, though not so strongly? And do not the organs of sight, the eye, the heart, and brains, resist that pressure by an endeavour of restitution outwards? Why then should there not be without and before the eye, an apparition of light in this case as well as in the other? _A._ I grant there must. But what is that which appears after the pressing of the eye? For there is nothing without that was not there before; or if there were, methinks another should see it better, or as well as he; or if in the dark, methinks it should enlighten the place. _B._ It is a fancy, such as is the appearance of your face in a looking-glass; such as is a dream; such as is a ghost; such as is a spot before the eye that hath stared upon the sun or fire. For all these are of the regiment of fancy, without any body concealed under them, or behind them, by which they are produced. _A._ And when you look towards the sun or moon, why is not that also which appears before your eyes at that time a fancy? _B._ So it is. Though the sun itself be a real body, yet that bright circle of about a foot diameter cannot be the sun, unless there be two suns, a greater and a lesser. And because you may see that which you call the sun, both above you in the sky, and before you in the water, and two suns, by distorting your eye, in two places in the sky, one of them must needs be fancy. And if one, both. All sense is fancy, though the cause be always in a real body. _A._ I see by this that those things which the learned call the accidents of bodies, are indeed nothing else but diversity of fancy, and are inherent in the sentient, and not in the objects, except motion and quantity. And I perceive by your doctrine you have been tampering with _Leviathan_ . But how comes wood with a certain degree of heat to shine, and iron also with a greater degree; but no heat at all to be able to make water shine? _B._ That which shineth hath the same motion in its parts that I have all this while supposed in the sun and earth. In which motion there must needs be a competent degree of swiftness to move the sense, that is, to make it visible. All bodies that are not fluid will shine with heat, if the heat be very great. Iron will shine and gold will shine; but water will not, because the parts are carried away before they attain to that degree of swiftness which is requisite. _A._ There are many fluid bodies whose parts evaporate, and yet they make a flame, as oil, and wine, and other strong drinks.