| Upon the removal of the ideas of these sensible qualities, they are utterly annihilated to the thought or imagination. |
| Now such as the parts are, such is the whole. |
| If a point be not considered as coloured or tangible, it can convey to us no idea; and consequently the idea of extension, which is composed of the ideas of these points, can never possibly exist. |
| But if the idea of extension really can exist, as we are conscious it does, its parts must also exist; and in order to that, must be considered as coloured or tangible. |
| We have therefore no idea of space or extension, but when we regard it as an object either of our sight or feeling. |
| The same reasoning will prove, that the indivisible moments of time must be filled with some real object or existence, whose succession forms the duration, and makes it be conceivable by the mind. |
| SECT. IV. OBJECTIONS ANSWERED. |
| Our system concerning space and time consists of two parts, which are intimately connected together. |
| The first depends on this chain of reasoning. |
| The capacity of the mind is not infinite; consequently no idea of extension or duration consists of an infinite number of parts or inferior ideas, but of a finite number, and these simple and indivisible: It is therefore possible for space and time to exist conformable to this idea: And if it be possible, it is certain they actually do exist conformable to it; since their infinite divisibility is utterly impossible and contradictory. |
| The other part of our system is a consequence of this. |
| The parts, into which the ideas of space and time resolve themselves, become at last indivisible; and these indivisible parts, being nothing in themselves, are inconceivable when not filled with something real and existent. |
| The ideas of space and time are therefore no separate or distinct ideas, but merely those of the manner or order, in which objects exist: Or in other words, it is impossible to conceive either a vacuum and extension without matter, or a time, when there was no succession or change in any real existence. |
| The intimate connexion betwixt these parts of our system is the reason why we shall examine together the objections, which have been urged against both of them, beginning with those against the finite divisibility of extension. |
| I.The first of these objections, which I shall take notice of, is more proper to prove this connexion and dependence of the one part upon the other, than to destroy either of them. |
| It has often been maintained in the schools, that extension must be divisible, in infinitum, because the system of mathematical points is absurd; and that system is absurd, because a mathematical point is a non-entity, and consequently can never by its conjunction with others form a real existence. |
| This would be perfectly decisive, were there no medium betwixt the infinite divisibility of matter, and the non-entity of mathematical points. |
| But there is evidently a medium, viz. the bestowing a colour or solidity on these points; and the absurdity of both the extremes is a demonstration of the truth and reality of this medium. |
| The system of physical points, which is another medium, is too absurd to need a refutation. |
| A real extension, such as a physical point is supposed to be, can never exist without parts, different from each other; and wherever objects are different, they are distinguishable and separable by the imagination. |
| II. The second objection is derived from the necessity there would be of PENETRATION, if extension consisted of mathematical points. |