To the unthinking person nothing seems simpler, more obvious, than his own existence—and hardly needing definition. Yet the least thought shows how complex and elusive this ‘self’ is. It is one of those cases with which the world teems—a juggle of the open daylight—in which an object _appears_ so perfectly simple, frank, innocent, and without concealment, and yet is really profoundly complex, deliberate, and unfathomable. The most elementary considerations easily illustrate what I mean.[138] When we speak of the ego, do we mean the self of to-day, or of yesterday, or of some years back—or possibly some years in the future when we shall have found the expression now unhappily denied us? Do we mean the self of boyhood, or even of babyhood? or do we mean that of maturity, or of old age? Do we mean the self indicated by the mind alone, or by the spirit, apart from the body? or do we mean that indicated specially by the body, or even (as some folk seem to consider) by the _clothes_? It would be very puzzling to be asked to place one’s finger, so to speak, on any one of these manifestations as really and completely representative. Rather perhaps we should be inclined, if pressed, to say that our real self was something underrunning _all_ these forms—that it required all the expressions, from infancy, through maturity, even to old age, and all the apparatus of body and mind, in order to convey its meaning; and that to pin it down to any particular moment of time, or to any particular phase of the material or spiritual, would be to do it a great injustice. If so, we seem at once compelled to think of the Self as something greatly larger than any ordinary form of it that we know, as something perhaps on a different plane of being—underrunning, and therefore in a sense beyond, Time; and similarly underrunning, and therefore in a sense beyond, both body and mind. And this all the more, because, as I have said on an earlier page, we all feel that at best much of our real selves remains in life-long defect of expression; and that there are great deeps of the Under-self (as in chapter viii.) which, though organically related to our ordinary consciousness, are still for the most part hidden and unexplored. All, in fact, points to the existence within us of a very profound self, which so far we may justifiably conclude to be much greater than any one known manifestation of it; which requires for its expression the forms of a lifetime; and still stretches on and beyond; which perhaps belongs to another sphere of being—as the ship in the air and the sunlight belongs to another sphere than the hull buried deep in the water.