The fundamental problem for Metaphysics is, of course, whether space and time are ultimate Realities or only appearances; that is, would the whole system of Reality, as directly apprehended by an absolute all-containing experience, wear the forms of extension and succession in time, or is it merely a consequence of the limitations of our own finite experience that things come to us in this guise? It may indeed be urged that the contents of the universe must form an order of some sort for the absolute experience, in virtue of their systematic unity, but even so it is not clear that order as such is necessarily spatial or temporal. Indeed, most of the forms of order with which we are acquainted, both in everyday life and in our mathematical studies, appear to be, properly speaking, both non-spatial and non-temporal. Thus, _e.g._, it is seemingly by a mere metaphor that we speak of the “successive” integers of the natural number-series, the “successive” powers of an algebraical symbol, the “successive” approximations to the value of a continued fraction, in language borrowed from the temporal flow of events, the true relation involved being in the first two cases the non-temporal one of logical derivation, and in the third the equally non-temporal one of resemblance to an ideal standard. The full solution of the metaphysical problem of space and time would thus involve (1) the discrimination of spatial and temporal order from other allied forms of order, and (2) a decision as to the claim of this special form of order to be ultimately coherent and intelligible.