| If it be a sufficient proof, that we have the idea of a vacuum, because we dispute and reason concerning it; we must for the same reason have the idea of time without any changeable existence; since there is no subject of dispute more frequent and common. |
| But that we really have no such idea, is certain. |
| For whence should it be derived? Does it arise from an impression of sensation or of reflection? Point it out distinctly to us, that we may know its nature and qualities. |
| But if you cannot point out any such impression, you may be certain you are mistaken, when you imagine you have any such idea. |
| But though it be impossible to shew the impression, from which the idea of time without a changeable existence is derived; yet we can easily point out those appearances, which make us fancy we have that idea. |
| For we may observe, that there is a continual succession of perceptions in our mind; so that the idea of time being for ever present with us; when we consider a stedfast object at five-a-clock, and regard the same at six; we are apt to apply to it that idea in the same manner as if every moment were distinguished by a different position, or an alteration of the object. |
| The first and second appearances of the object, being compared with the succession of our perceptions, seem equally removed as if the object had really changed. |
| To which we may add, what experience shews us, that the object was susceptible of such a number of changes betwixt these appearances; as also that the unchangeable or rather fictitious duration has the same effect upon every quality, by encreasing or diminishing it, as that succession, which is obvious to the senses. |
| From these three relations we are apt to confound our ideas, and imagine we can form the idea of a time and duration, without any change or succession. |
| SECT. VI. OF THE IDEA OF EXISTENCE, AND OF EXTERNAL EXISTENCE. |
| It may not be amiss, before we leave this subject, to explain the ideas of existence and of external existence; which have their difficulties, as well as the ideas of space and time. |
| By this means we shall be the better prepared for the examination of knowledge and probability, when we understand perfectly all those particular ideas, which may enter into our reasoning. |
| There is no impression nor idea of any kind, of which we have any consciousness or memory, that is not conceived as existent; and it is evident, that from this consciousness the most perfect idea and assurance of being is derived. |
| From hence we may form a dilemma, the most clear and conclusive that can be imagined, viz. |
| that since we never remember any idea or impression without attributing existence to it, the idea of existence must either be derived from a distinct impression, conjoined with every perception or object of our thought, or must be the very same with the idea of the perception or object. |
| As this dilemma is an evident consequence of the principle, that every idea arises from a similar impression, so our decision betwixt the propositions of the dilemma is no more doubtful. |
| go far from there being any distinct impression, attending every impression and every idea, that I do not think there are any two distinct impressions, which are inseparably conjoined. |
| Though certain sensations may at one time be united, we quickly find they admit of a separation, and may be presented apart. |
| And thus, though every impression and idea we remember be considered as existent, the idea of existence is not derived from any particular impression. |
| The idea of existence, then, is the very same with the idea of what we conceive to be existent. |
| To reflect on any thing simply, and to reflect on it as existent, are nothing different from each other. |