| The case is not the same with relation to external objects. |
| Those require a continued existence, or otherwise lose, in a great measure, the regularity of their operation. |
| I am here seated in my chamber with my face to the fire; and all the objects, that strike my senses, are contained in a few yards around me. |
| My memory, indeed, informs me of the existence of many objects; but then this information extends not beyond their past existence, nor do either my senses or memory give any testimony to the continuance of their being. |
| When therefore I am thus seated, and revolve over these thoughts, I hear on a sudden a noise as of a door turning upon its hinges; and a little after see a porter, who advances towards me. |
| This gives occasion to many new reflections and reasonings. |
| First, I never have observed, that this noise coued proceed from any thing but the motion of a door; and therefore conclude, that the present phaenomenon is a contradiction to all past experience, unless the door, which I remember on the other side the chamber, be still in being. |
| Again, I have always found, that a human body was possest of a quality, which I call gravity, and which hinders it from mounting in the air, as this porter must have done to arrive at my chamber, unless the stairs I remember be not annihilated by my absence. |
| But this is not all. |
| I receive a letter, which upon, opening it I perceive by the hand-writing and subscription to have come from a friend, who says he is two hundred leagues distant. |
| It is evident I can never account for this phenomenon, conformable to my experience in other instances, without spreading out in my mind the whole sea and continent between us, and supposing the effects and continued existence of posts and ferries, according to my Memory and observation. |
| To consider these phaenomena of the porter and letter in a certain light, they are contradictions to common experience, and may be regarded as objections to those maxims, which we form concerning the connexions of causes and effects. |
| I am accustomed to hear such a sound, and see such an object in motion at the same time. |
| I have not received in this particular instance both these perceptions. |
| These observations are contrary, unless I suppose that the door still remains, and that it was opened without my perceiving it: And this supposition, which was at first entirely arbitrary and hypothetical, acquires a force and evidence by its being the only one, upon which I can reconcile these contradictions. |
| There is scarce a moment of my life, wherein there is not a similar instance presented to me, and I have not occasion to suppose the continued existence of objects, in order to connect their past and present appearances, and give them such an union with each other, as I have found by experience to be suitable to their particular natures and circumstances. |
| Here then I am naturally led to regard the world, as something real and durable, and as preserving its existence, even when it is no longer present to my perception. |
| But though this conclusion from the coherence of appearances may seem to be of the same nature with our reasonings concerning causes and effects; as being derived from custom, and regulated by past experience; we shall find upon examination, that they are at the bottom considerably different from each other, and that this inference arises from the understanding, and from custom in an indirect and oblique manner. |
| For it will readily be allowed, that since nothing is ever really present to the mind, besides its own perceptions, it is not only impossible, that any habit should ever be acquired otherwise than by the regular succession of these perceptions, but also that any habit should ever exceed that degree of regularity. |
| Any degree, therefore, of regularity in our perceptions, can never be a foundation for us to infer a, greater degree of regularity in some objects, which are not perceived; since this supposes a contradiction, viz. |
| a habit acquired by what was never present to the mind. |