This fact of the mystery of our own existence is full of material for thought. It is in itself startling--even appalling. We feel that it is a solemn, a dreadful, thing to exist, and to exist in that limitless space and that eternal time which we can no more understand than we can our own constitution, though our belief in their existence is inevitable. Nor can we divest ourselves of anxious thoughts as to the source, tendencies, and end of our own being. Here, in short, we already reach the threshold of that dread unknown future and its possibilities, the realization of which by hope, fear, and imagination constitutes, perhaps, our first introduction to the unseen world as distinguished from the present world of sense. The agnostic may smile if he pleases at religion as a puerile fancy, but he knows, like other men, that the mere consciousness of existence necessarily links itself with a future--nay, unending--existence, and that any being with this consciousness of futurity must have at least a religion of hope and fear. In this we find an intelligible reason for the universality of religious ideas in relation to a future life. Even where this leads to beliefs that may be called superstitious, it is more reasonable than Agnosticism; for it is surely natural that a being inscrutable by himself should be led to believe in the existence of other things equally inscrutable, but apparently related to himself. But the thinking "I" dwells in the midst of what we term external objects. In a certain sense it treats the parts of its own bodily organism as if they were things external to it, speaking of "my hand," "my head," as if they were its property. But there are things practically infinite beyond the organism itself. We call them objects or things, but they are only appearances; and we know only their relations to ourselves and to each other. Their essence, if they have any, is inscrutable. We say that the appearances indicate matter and energy, but what these are essentially we know not. We reduce matter to atoms, but it is impossible for us to have any conception of an atom or of the supposed ether, whether itself in some sense atomic or not, including such atoms. Our attempts to form rational conceptions of atoms resolve themselves into complex conjectures as to vortices of ethers and the like, of which no one pretends to have any distinct mental picture; yet on this basis of the incomprehensible rests all our physical science, the first truths in which are really matters of pure faith in the existence of that which we cannot understand. Yet all men would scoff at the agnostic who on this account should express unbelief in physical science.