"Did men who publish controversial papers, accustom themselves to write with that candour and ingenuity with which you propose your difficulties, I am persuaded almost all disputes might be very amicably terminated, either by men's coming at last to agree in opinion, or at least finding reason to suffer each other friendly to differ.
"Your two objections are very ingenious, and urged with great strength and acuteness. Yet I am not without hopes of being able to give you satisfaction in both of them. To your first, therefore, I answer: Whatever may, without a contradiction, be absent from any one place at any one time, may also, without a contradiction, be absent from all places at all times. For, whatever is absolutely necessary at all, is absolutely necessary in every part of space, and in every point of duration. Whatever can at any time be conceived possible to be absent from any one part of space, may, for the same reason, [viz. the implying no contradiction in the nature of things,] be conceived possible to be absent from every other part of space at the same time, either by ceasing to be, or by supposing it never to have begun to be. Your instance about demonstrating a man to live 1000 years, is what (I think) led you into the mistake; and is a good instance to lead you out of it again. You may suppose a man shall live 1000 years, or God may reveal and promise he shall live 1000 years; and, upon that supposition, it shall not be possible for the man to be absent from all places in any part of that time. Very true; but why shall it not be possible? Only because it is contrary to the supposition, or to the promise of God; but not contrary to the absolute nature of things, which would be the case if the man existed necessarily, as every part of space does. In supposing you could demonstrate a man should live 1000 years, or one year, you make an impossible and contradictory supposition. For though you may know certainly, (by revelation, suppose,) that he will live so long, yet this is only the certainty of a thing true in fact, not in itself necessary: And demonstration is applicable to nothing but what is necessary in itself, necessary in all places and at all times equally.
"To your second difficulty, I answer: What exists necessarily, not only must so exist alone, as to be independent of any thing else; but (being self-sufficient,) may also so exist alone as that every thing else may possibly (or without any contradiction in the nature of things) be supposed not to exist at all; and consequently, (since that which may possibly be supposed not to exist at all, is not necessarily existent,) no other thing can be necessarily existent. Whatever is necessarily existing, there is need of its existence in order to the supposal of the existence of any other thing; so that nothing can possibly be supposed to exist, without presupposing and including antecedently the existence of that which is necessary. For instance; the supposal of the existence of any thing whatever, includes necessarily a presupposition of the existence of space and time; and, if any thing could exist without space or time, it would follow that space and time were not necessarily-existing. Therefore, the supposing any thing possibly to exist alone, so as not necessarily to include the presupposal of some other thing, proves demonstrably that that other thing is not necessarily-existing; because, whatever has necessity of existence, cannot possibly, in any conception whatsoever, be supposed away. There cannot possibly be any notion of the existence of any thing, there cannot possibly be any notion of existence at all, but what shall necessarily pre-include the notion of that which has necessary existence: And consequently the two propositions which you judged independent are really necessarily connected. These sorts of things are indeed very difficult to express, and not easy to be conceived but by very attentive minds: But to such as can and will attend, nothing (I think) is more demonstrably convictive."
"If any thing still sticks with you in this, or any other part of my books, I shall be very willing to be informed of it; who am,"
"Sir, your assured Friend and Servant,
"P. S. Many readers, I observe, have misunderstood my second general proposition; as if the words [some one unchangeable and independent being] meant [one only -- being,] whereas the true meaning, and all that the argument there requires, is, [some one at least.] That there can be but one, is the thing proved afterwards in the seventh proposition."