and by the degrees of light and shade;—­and to the feeling, that which consists in a sensation of motion in the hand, or other member of the body.  In vain should we. search any farther.  On whichever side we turn this subject, we shall find that these are the only impressions such an object can produce after the supposed annihilation; and it has already been remarked, that impressions can give rise to no ideas, but to such as resemble them.

Since a body interposed betwixt two others may be supposed to be annihilated, without producing any change upon such as lie on each hand of it, it is easily conceived, how it may be created anew, and yet produce as little alteration.  Now the motion of a body has much the same effect as its creation.  The distant bodies are no more affected in the one case, than in the other.  This suffices to satisfy the imagination, and proves there is no repugnance in such a motion.  Afterwards experience comes in play to persuade us that two bodies, situated in the manner above-described, have really such a capacity of receiving body betwixt them, and that there is no obstacle to the conversion of the invisible and intangible distance into one that is visible and tangible.  However natural that conversion may seem, we cannot be sure it is practicable, before we have had experience of it.

Thus I seem to have answered the three objections above-mentioned; though at the same time I am sensible, that few will be satisfyed with these answers, but will immediately propose new objections and difficulties.  It will probably be said, that my reasoning makes nothing to the matter in hands and that I explain only the manner in which objects affect the senses, without endeavouring to account for their real nature and operations.  Though there be nothing visible or tangible interposed betwixt two bodies, yet we find by experience, that the bodies may be placed in the same manner, with regard to the eye, and require the same motion of the hand in passing from one to the other, as if divided by something visible and tangible.  This invisible and intangible distance is also found by experience to contain a capacity of receiving body, or of becoming visible and tangible.  Here is the whole of my system; and in no part of it have I endeavoured to explain the cause, which separates bodies after this manner, and gives them a capacity of receiving others betwixt them, without any impulse or penetration.

I answer this objection, by pleading guilty, and by confessing that my intention never was to penetrate into the nature of bodies, or explain the secret causes of their operations.  For besides that this belongs not to my present purpose, I am afraid, that such an enterprise is beyond the reach of human understanding, and that we can never pretend to know body otherwise than by those external properties, which discover themselves to the senses.  As to those who attempt any thing farther, I cannot approve of their ambition, till