To "explain" is in one way or another to liken the less known to what is better known; and thus every philosophy is an attempt to express--by means of sundry extensions and limitations--the universe of our experience in the terms of some totality with which we are more familiar; plainly, it is also an endeavour to express the greater in terms of the less, and must therefore be almost infinitely inadequate even at the best. At one time the Whole has been conceived as the unity of a mere aggregate--of a heap of stones; at another, as a mere sand-storm of fortuitous atoms; there has been the egg-theory, and the tortoise-theory, and many others, no less grotesque to our seeming. But, leaving fanciful and poetical philosophies aside, and considering only those which pretend to be strictly rational, we find the objective philosophy and the subjective confronting one another; the former likening the universe to the works of men's hands; the latter likening it to man himself; the former taking its metaphors from the artificer shaping his material according to a preconceived plan for a definite purpose; the latter, from the thinking and willing self considered as the creator of its own personal experience. There is enough uniformity of plan throughout the animal body to make any one part of the organism a likeness of the whole--the eye, the heart, or the hand. And so, presumably, there is hardly any unity we can think of in our own little corner of experience that does not offer some similitude of the universal unity. But to take this as an adequate explanation; to force the metaphor to its logical consequences, to the exclusion of every other reasonable though non-rational assent, is the commonest but most fatal form of intellectual provincialism and narrowness. Our mind is essentially limited not merely in that it cannot know everything, but in that its mode of knowledge is imperfect and analogical in regard to all that is greater than itself. It is broad only when conscious of its narrowness. The first difficulty into which idealism gets itself is that of solipsism. According to its rigidly argued principles, "mind is separated from mind by a barrier which is, not figuratively, but literally impassable. It is impossible for any _ego_ to leap this barrier and enter into the experience of any other _ego_." It is not an abstract self-in-general, but my one solitary concrete self for which all experience exists. There is no room for any other person. But this philosophy does not account for our common-sense belief in Nature as existing independently of self and of other selfs; or in those other selfs with their several and distinct spheres of experience.