It may be said at once that it is, undoubtedly, the very best illustration of these social relations that we can draw from nature, and it is of real value. It has had, moreover, as already indicated, a most influential and largely honorable history in the development of the thought of men. Its classical expression is in the epoch-making twelfth chapter of I Corinthians, which makes so plain the ethical applications of the analogy. II. THE INEVITABLE INADEQUACY OF THE ANALOGY 1. _Comes from the Sub-personal World._--But it ought clearly to be seen, on the other hand, that, considered as a complete expression of the social consciousness, it is necessarily inadequate; and it is of moment that we should not be dominated by it. Too often it has been made to cover the entire ground, as though in itself it were a complete expression and final explanation of the social consciousness, instead of a quite incomplete illustration. For, in the first place, the very fact that the analogy comes from the physical world, from the sub-personal realm, makes it certain that it must fail at vital points in the expression of what is peculiarly a personal and ethical fact. We cannot safely argue directly from the physical illustration to ethical propositions. 2. _Access to Reality, Only Through Ourselves._--Moreover, in this day of extraordinary attention to the physical world, it is particularly important that we should keep constantly in mind that we have direct access to reality only in ourselves; that man is himself necessarily the only key which we can use for any ultimate understanding of anything; or, as Paulsen puts it, "I know reality as it is in itself, in so far as I am real myself, or in so far as it is, or is like, that which I am, namely, spirit."[13] We are not to forget that, in very truth, we know _better_ what we mean by persons and personal relations, than we do what we mean by members of a body and by organic relations; and, further, that in point of fact, all those metaphysical notions by which we strive to think things are ultimately derived from ourselves; and that then we illogically turn back upon our own minds, from which all these notions came, to explain the mind in the same secondary way in which we explain other things.