Shall we not say, however, that the superior attraction of the new in competition with established lines of expenditure only indicates the greater "satiation" of the wants the latter represent and the comparative freshness of the wants the novelty will satisfy? On the contrary the latter wants are in the full sense not yet existent, the new satisfactions are untried and unmeasured; the older wants have the advantage of position, and if satiated today, will reassert themselves with a predictable strength tomorrow. The new wants, it is true, if they are acquired, will be part of a new system, but the present fact remains that their full meaning cannot be known in advance of trial and the further outlines of the new scheme of uses and values cannot be drawn up until this meaning has been learned. If, then, the new commodity is taken, it is not because the promised satisfaction and the sum of known utilities to be sacrificed are found equal, nor again because the new commodity will fit neatly into a place in the existing schedule that can be vacated for it. This latter is the case of substitution. Such an interpretation of the facts is retrospective only; it is a formal declaration that the exchange has been deemed on the whole worth while, but the reasons for this outcome such a formula is powerless to suggest. In general the new commodity and the habits it engenders could not remain without effect upon a system into which they might be mechanically introduced. Certain items in the schedule, associated in use with those dispensed with for the new, must be rendered obsolete by the change. The new interests called into play will draw to themselves and to their further development attention which may be in large measure diverted from the interests of older standing. And in the new system all interests remaining over from the old will accordingly stand in a new light and their objects will be valued, will be held important, for reasons that will need fresh statement.[53]