Indeed, it is obvious from first principles that when the sets of terms between which a number of relations of the same type holds are indistinguishable, the relations cannot be discriminated. To distinguish directions at all, we must, in the end, take at least our starting-point and one or more standard directions reckoned from it—according to the number of dimensions with which we are dealing—as independently given, that is, as having recognisable qualitative differences from other possible starting-points and standard directions. (Thus, to distinguish before and after in conceptual time, you must at least assume some moment of time, qualitatively recognisable from others, as the epoch from which you reckon, and must also have some recognisable qualitative distinction between the direction “past” and the direction “future.”) And with this reference to qualitative differences we are at once thrown back, as in the case of perceptual time and space, on the insoluble old problem of Quality and Relation. The assumed starting-point and standard directions _must_ have qualitative individuality, or they could not be independently recognised and made the basis for discrimination between the remaining directions and positions: yet, because of the necessary homogeneity of the space and time of conceptual construction, they _cannot_ have any such qualitative individuality, but must be _arbitrarily_ assumed. They will therefore themselves be capable of determination only by reference to some other equally arbitrary standard, and thus we are once more committed to the indefinite regress. The practical usefulness of these constructions thus depends on the very fact that we are not consistent in our use of them. In all practical applications we use them to map out the spatial and temporal order of events as seen in perspective from a standpoint which is, as regards the conceptual time and space order itself, arbitrary and indistinguishable from others.