| Thus the principle of individuation is nothing but the INVARIABLENESS and UNINTERRUPTEDNESS of any object, thro a supposd variation of time, by which the mind can trace it in the different periods of its existence, without any break of the view, and without being obligd to form the idea of multiplicity or number. |
| I now proceed to explain the SECOND part of my system, and shew why the constancy of our perceptions makes us ascribe to them a perfect numerical identity, tho there be very long intervals betwixt their appearance, and they have only one of the essential qualities of identity, VIZ, INVARIABLENESS. |
| That I may avoid all ambiguity and confusion on this head, I shall observe, that I here account for the opinions and belief of the vulgar with regard to the existence of body; and therefore must entirely conform myself to their manner of thinking and of expressing themselves. |
| Now we have already observd, that however philosophers may distinguish betwixt the objects and perceptions of the senses; which they suppose co-existent and resembling; yet this is a distinction, which is not comprehended by the generality of mankind, who as they perceive only one being, can never assent to the opinion of a double existence and representation. |
| Those very sensations, which enter by the eye or ear, are with them the true objects, nor can they readily conceive that this pen or paper, which is immediately perceivd, represents another, which is different from, but resembling it. |
| In order, therefore, to accommodate myself to their notions, I shall at first suppose; that there is only a single existence, which I shall call indifferently OBJECT or PERCEPTION, according as it shall seem best to suit my purpose, understanding by both of them what any common man means by a hat, or shoe, or stone, or any other impression, conveyd to him by his senses. |
| I shall be sure to give warning, when I return to a more philosophical way of speaking and thinking. |
| To enter, therefore, upon the question concerning the source of the error and deception with regard to identity, when we attribute it to our resembling perceptions, notwithstanding their interruption; I must here recal an observation, which I have already provd and explaind [Part II. SECT. 5.]. |
| Nothing is more apt to make us mistake one idea for another, than any relation betwixt them, which associates them together in the imagination, and makes it pass with facility from one to the other. |
| Of all relations, that of resemblance is in this respect the most efficacious; and that because it not only causes an association of ideas, but also of dispositions, and makes us conceive the one idea by an act or operation of the mind, similar to that by which we conceive the other. |
| This circumstance I have observd to be of great moment; and we may establish it for a general rule, that whatever ideas place the mind in the same disposition or in similar ones, are very apt to be confounded. |
| The mind readily passes from one to the other, and perceives not the change without a strict attention, of which, generally speaking, it is wholly incapable. |
| In order to apply this general maxim, we must first examine the disposition of the mind in viewing any object which preserves a perfect identity, and then find some other object, that is confounded with it, by causing a similar disposition. |
| When we fix our thought on any object, and suppose it to continue the same for some time; it is evident we suppose the change to lie only in the time, and never exert ourselves to produce any new image or idea of the object. |
| The faculties of the mind repose themselves in a manner, and take no more exercise, than what is necessary to continue that idea, of which we were formerly possest, and which subsists without variation or interruption. |
| The passage from one moment to another is scarce felt, and distinguishes not itself by a different perception or idea, which may require a different direction of the spirits, in order to its conception. |
| Now what other objects, beside identical ones, are capable of placing the mind in the same disposition, when it considers them, and of causing the same uninterrupted passage of the imagination from one idea to another? This question is of the last importance. |
| For if we can find any such objects, we may certainly conclude, from the foregoing principle, that they are very naturally confounded with identical ones, and are taken for them in most of our reasonings. |
| But though this question be very important, it is not very difficult nor doubtful. |
| For I immediately reply, that a succession of related objects places the mind in this disposition, and is considered with the same smooth and uninterrupted progress of the imagination, as attends the view of the same invariable object. |
| The very nature and essence of relation is to connect our ideas with each other, and upon the appearance of one, to facilitate the transition to its correlative. |