§ 7. Instead of further elaborating this general argument, a task which would be superfluous if its principle is grasped, and unconvincing if it is missed, I will proceed to point out one or two special ways in which the essential arbitrariness of the spatial and temporal construction is strikingly exemplified. To begin with, a word may be said about the alleged _unity_ of space and time. It is constantly taken for granted, by philosophers as well as by practical men, that there can be only _one_ spatial and one temporal order, so that all spatial relations, and again all temporal relations, belong to the same system. Thus, if A has a spatial relation to B and C to D, it is assumed that there must be spatial relations between A and C, A and D, and B and C, B and D. Similarly if A is temporally related with B, and C with D. This view is manifestly presupposed in the current conception of Nature, the “physical universe,” the “physical order,” as the aggregate of all processes in space and time. But there seems to be no real logical warrant for it. In principle the alleged unity of all spatial and temporal relations might be dismissed, on the strength of the one consideration that space and time are not individual wholes, and therefore can contain no principle of internal structural unity. This is manifest from the method by which the space and time of our conceptual scheme have been constructed. They arose, as we saw, from the indefinite repetition of a single type of relation between terms in which we were unable to find any ultimately intelligible principle of internal structure. But unity of structure cannot be brought into that which does not already possess it by such mere endless repetition. The result of such a process will be as internally incoherent and devoid of structure as the original data. Hence space and time, being mere repetitions of the scheme of qualities in relation, cannot be true unities.