Descartes' Loneliness

Toward evening, the natural light becomes intelligent and answers, without demur: “Be assured! You are not alone. . . .” But in fact, toward evening, I am not convinced there is any other except myself to whom existence necessarily pertains. I also interrogate myself to discover whether I myself possess any power by which I can bring it about that I who now am shall exist another moment. Because I am mostly a thinking thing and because this precise question can only be from that thoughtful part of myself, if such a power did reside within me I should, I am sure, be conscious of it. . . . But I am conscious of no such power. And yet, if I myself cannot be the cause of that assurance, surely it is necessary to conclude that I am not alone in the world. There is some other who is the cause of that idea. But if, at last, no such other can be found toward evening, do I really have sufficient assurance of the existence of any other being at all? For, after a most careful search, I have been unable to discover the ground of that conviction—unless it be imagined a lonely workman on a dizzy scaffold unfolds a sign at evening and puts his mark to it.