| In order to know whether any objects, which are joined in impression, be inseparable in idea, we need only consider, if they be different from each other; in which case, it is plain they may be conceived apart. |
| Every thing, that is different is distinguishable: and everything, that is distinguishable, may be separated, according to the maxims above-explained. |
| If on the contrary they be not different, they are not distinguishable: and if they be not distinguishable, they cannot be separated. |
| But this is precisely the case with respect to time, compared with our successive perceptions. |
| The idea of time is not derived from a particular impression mixed up with others, and plainly distinguishable from them; but arises altogether from the manner, in which impressions appear to the mind, without making one of the number. |
| Five notes played on a flute give us the impression and idea of time; though time be not a sixth impression, which presents itself to the hearing or any other of the senses. |
| Nor is it a sixth impression, which the mind by reflection finds in itself. |
| These five sounds making their appearance in this particular manner, excite no emotion in the mind, nor produce an affection of any kind, which being observed by it can give rise to a new idea. |
| For that is necessary to produce a new idea of reflection, nor can the mind, by revolving over a thousand times all its ideas of sensation, ever extract from them any new original idea, unless nature has so framed its faculties, that it feels some new original impression arise from such a contemplation. |
| But here it only takes notice of the manner, in which the different sounds make their appearance; and that it may afterwards consider without considering these particular sounds, but may conjoin it with any other objects. |
| The ideas of some objects it certainly must have, nor is it possible for it without these ideas ever to arrive at any conception of time; which since it, appears not as any primary distinct impression, can plainly be nothing but different ideas, or impressions, or objects disposed in a certain manner, that is, succeeding each other. |
| I know there are some who pretend, that the idea of duration is applicable in a proper sense to objects, which are perfectly unchangeable; and this I take to be the common opinion of philosophers as well as of the vulgar. |
| But to be convinced of its falsehood we need but reflect on the foregoing conclusion, that the idea of duration is always derived from a succession of changeable objects, and can never be conveyed to the mind by any thing stedfast and unchangeable. |
| For it inevitably follows from thence, that since the idea of duration cannot be derived from such an object, it can never-in any propriety or exactness be applied to it, nor can any thing unchangeable be ever said to have duration. |
| Ideas always represent the Objects or impressions, from which they are derived, and can never without a fiction represent or be applied to any other. |
| By what fiction we apply the idea of time, even to what is unchangeable, and suppose, as is common, that duration is a measure of rest as well as of motion, we shall consider [Sect 5.] afterwards. |
| There is another very decisive argument, which establishes the present doctrine concerning our ideas of space and time, and is founded only on that simple principle, that our ideas of them are compounded of parts, which are indivisible. |
| This argument may be worth the examining. |
| Every idea, that is distinguishable, being also separable, let us take one of those simple indivisible ideas, of which the compound one of extension is formed, and separating it from all others, and considering it apart, let us form a judgment of its nature and qualities. |
| It is plain it is not the idea of extension. |
| For the idea of extension consists of parts; and this idea, according to t-he supposition, is perfectly simple and indivisible. |