| What then do we suppose in this case, but that these objects still continue their usual connexion, notwithstanding their apparent interruption, and that the irregular appearances are joined by something, of which we are insensible? But as all reasoning concerning matters of fact arises only from custom, and custom can only be the effect of repeated perceptions, the extending of custom and reasoning beyond the perceptions can never be the direct and natural effect of the constant repetition and connexion, but must arise from the co-operation of some other principles. |
| I have already observed [Part II, SECT. 4.], in examining the foundation of mathematics, that the imagination, when set into any train of thinking, is apt to continue, even when its object fails it, and like a galley put in motion by the oars, carries on its course without any new impulse. |
| This I have assigned for the reason, why, after considering several loose standards of equality, and correcting them by each other, we proceed to imagine so correct and exact a standard of that relation, as is not liable to the least error or variation. |
| The same principle makes us easily entertain this opinion of the continued existence of body. |
| Objects have a certain coherence even as they appear to our senses; but this coherence is much greater and more uniform, if we suppose the object.% to have a continued existence; and as the mind is once in the train of observing an uniformity among objects, it naturally continues, till it renders the uniformity as compleat as possible. |
| The simple supposition of their continued existence suffices for this purpose, and gives us a notion of a much greater regularity among objects, than what they have when we look no farther than our senses. |
| But whatever force we may ascribe to this principle, I am afraid it is too weak to support alone so vast an edifice, as is that of the continued existence of all external bodies; and that we must join the constancy of their appearance to the coherence, in order to give a satisfactory account of that opinion. |
| As the explication of this will lead me into a considerable compass of very profound reasoning; I think it proper, in order to avoid confusion, to give a short sketch or abridgment of my system, and afterwards draw out all its parts in their full compass. |
| This inference from the constancy of our perceptions, like the precedent from their coherence, gives rise to the opinion of the continued existence of body, which is prior to that of its distinct existence, and produces that latter principle. |
| When we have been accustomed to observe a constancy in certain impressions, and have found, that the perception of the sun or ocean, for instance, returns upon us after an absence or annihilation with like parts and in a like order, as at its first appearance, we are not apt to regard these interrupted perceptions as different, (which they really are) but on the contrary consider them as individually the same, upon account of their resemblance. |
| But as this interruption of their existence is contrary to their perfect identity, and makes us regard the first impression as annihilated, and the second as newly created, we find ourselves somewhat at a loss, and are involved in a kind of contradiction. |
| In order to free ourselves from this difficulty, we disguise, as much as possible, the interruption, or rather remove it entirely, by supposing that these interrupted perceptions are connected by a real existence, of which we are insensible. |
| This supposition, or idea of continued existence, acquires a force and vivacity from the memory of these broken impressions, and from that propensity, which they give us, to suppose them the same; and according to the precedent reasoning, the very essence of belief consists in the force and vivacity of the conception. |
| In order to justify this system, there are four things requisite. |
| First, To explain the PRINCIPIUM INDIVIDUATIONIS, or principle of identity. |
| Secondly, Give a reason, why the resemblance of our broken and interrupted perceptions induces us to attribute an identity to them. |
| Thirdly, Account for that propensity, which this illusion gives, to unite these broken appearances by a continued existence. |
| Fourthly and lastly, Explain that force and vivacity of conception, which arises from the propensity. |
| First, As to the principle of individuation; we may observe, that the view of any one object is not sufficient to convey the idea of identity. |
| For in that proposition, an object is the same with itself, if the idea expressed by the word, object, were no ways distinguished from that meant by itself; we really should mean nothing, nor would the proposition contain a predicate and a subject, which however are implyed in this affirmation. |
| One single object conveys the idea of unity, not that of identity. |