The unconditioned necessity, which we need so indispensably as the ultimate sustainer of all things, is for human reason the true abyss. Even eternity—however awful the sublimity with which a Haller might portray it—does not make such a dizzying impression on the mind; for eternity only measures the duration of things, but it does not sustain that duration. One cannot resist the thought of it, but one also cannot bear it that a being that we represent to ourselves as the highest among all possible beings might as it were, say to itself: "If I am from eternity to eternity, outside me is nothing except what is something merely through my will; but whence then am I? " Here everything gives way beneath us, and the greatest perfection as well the smallest, hovers without support before speculative reason, for which it would cost nothing to let the one as much as the other disappear without the least obstacle.
Immanuel Kant, Critique of Pure Reason, A613/B641













