The doctrine that plurality, interaction, change, and evolution are permanent traits of reality gains in clearness when contrasted with the opposed theories which involve creation, absolute origins, or temporal ultimates. The term 'ultimate origins' may be taken in a merely relative sense which is valid. The French language has an origin in the Latin tongues, which is an ultimate origin for French, but this is not an absolutely ultimate origin, since the Latin tongues, in their turn, have origins. It is, for instance, meaningless to inquire into the ultimate origin of the world as a whole; and it is equally futile to trace any part of the world back to an absolute origin. "That scientific inquiry does not itself deal with any question of ultimate origins, except in the purely relative sense already indicated, is, of course, recognized. But it also seems to follow from what has been said that scientific inquiry does not generate, or leave over, such a question for some other discipline, such as metaphysics, to deal with."[275] Theories like that of Laplace, for instance, trace the world back to an origin in some undifferentiated universe; or, in Spencer's terms, some state of homogeneity. From this original state the world is said to evolve. But the undifferentiated mass lacks the plurality, interaction, and change which are presupposed in all scientific explanation. These traits must be present before development can occur. "To get change we have to assume other structures which interact with it, existences not covered by the formula."[276] In short, although Dewey only implies this, all scientific explanation presupposes a system of interacting parts; nothing can be explained by reference to an undifferentiated world which lacks such traits. Dewey is particularly interested in the origin of mind or intelligence. In dealing with mind, he says, we must begin with the present, and in the present we find that the world has an organization, "in spots," of the kind we call intelligence. This existing intelligence cannot be explained by any theory which reduces it to something inferior. The "attempt to give an account of any occurrence involves the genuine and irreducible existence of the thing dealt with."[277] Mind cannot be explained by being explained away, nor can it be explained as a development out of an original source in which the potentiality, or direction of change towards mind, was lacking.