| mind by two senses, the sight and touch; nor does anything ever appear extended, that is not either visible or tangible. |
| That compound impression, which represents extension, consists of several lesser impressions, that are indivisible to the eye or feeling, and may be called impressions of atoms or corpuscles endowed with colour and solidity. |
| But this is not all. |
| It is not only requisite, that these atoms should be coloured or tangible, in order to discover themselves to our senses; it is also necessary we should preserve the idea of their colour or tangibility in order to comprehend them by our imagination. |
| There is nothing but the idea of their colour or tangibility, which can render them conceivable by the mind. |
| 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. |