| But whatever foundation there may be for a controversy concerning the things themselves, it may be pretended, that the very dispute is decisive concerning the idea, and that it is impossible men coued so long reason about a vacuum, and either refute or defend it, without having a notion of what they refuted or defended. |
| Secondly, If this argument should be contested, the reality or at least the possibility of the idea of a vacuum may be proved by the following reasoning. |
| Every idea is possible, which is a necessary and infallible consequence of such as are possible. |
| Now though we allow the world to be at present a plenum, we may easily conceive it to be deprived of motion; and this idea will certainly be allowed possible. |
| It must also be allowed possible, to conceive the annihilation of any part of matter by the omnipotence of the deity, while the other parts remain at rest. |
| For as every idea, that is distinguishable, is separable by the imagination; and as every idea, that is separable by the imagination, may be conceived to be separately existent; it is evident, that the existence of one particle of matter, no more implies the existence of another, than a square figure in one body implies a square figure in every one. |
| This being granted, I now demand what results from the concurrence of these two possible ideas of rest and annihilation, and what must we conceive to follow upon the annihilation of all the air and subtile matter in the chamber, supposing the walls to remain the same, without any motion or alteration? There are some metaphysicians, who answer, that since matter and extension are the same, the annihilation of one necessarily implies that of the other; and there being now no distance betwixt the walls of the chamber, they touch each other; in the same manner as my hand touches the paper, which is immediately before me. |
| But though this answer be very common, I defy these metaphysicians to conceive the matter according to their hypothesis, or imagine the floor and roof, with all the opposite sides of the chamber, to touch each other, while they continue in rest, and preserve the same position. |
| For how can the two walls, that run from south to north, touch each other, while they touch the opposite ends of two walls, that run from east to west? And how can the floor and. |
| roof ever meet, while they are separated by the four walls, that lie in a contrary position? If you change their position, you suppose a motion. |
| If you conceive any thing betwixt them, you suppose a new creation. |
| But keeping strictly to the two ideas of rest and annihilation, it is evident, that the idea, which results from them, is not that of a contact of parts, but something else; which is concluded to be the idea of a vacuum. |
| The third objection carries the matter still farther, and not only asserts, that the idea of a vacuum is real and possible, but also necessary and unavoidable. |
| This assertion is founded on the motion we observe in bodies, which, it is maintained, would be impossible and inconceivable without a vacuum, into which one body must move in order to make way for another.. |
| I shall not enlarge upon this objection, because it principally belongs to natural philosophy, which lies without our present sphere. |
| In order to answer these objections, we must take the matter pretty deep, and consider the nature and origin of several ideas, lest we dispute without understanding perfectly the subject of the controversy. |
| It is evident the idea of darkness is no positive idea, but merely the negation of .light, or more properly speaking, of coloured and visible objects. |
| A man, who enjoys his sight, receives no other perception from turning his eyes on every side, when entirely deprived of light, than what is common to him with one born blind; and it is certain such-a-one has no idea either of light or darkness. |
| The consequence of this is, that it is not from the mere removal of visible objects we receive the impression of extension without matter; and that the idea of utter darkness can never be the same with that of vacuum. |
| Suppose again a man to be Supported in the air, and to be softly conveyed along by some invisible power; it is evident he is sensible of nothing, and never receives the idea of extension, nor indeed any idea, from this invariable motion. |
| Even supposing he moves his limbs to and fro, this cannot convey to him that idea. |