To the modern scientist the phenomena of growth and change are the most obtrusive and most consequential facts observable in economic life. For an understanding of modern economic life the technological advance of the past two centuries--_e.g._, the growth of the industrial arts--is of the first importance; but marginal-utility theory does not bear on this matter, nor does this matter bear on marginal-utility theory. As a means of theoretically accounting for this technological movement in the past or in the present, or even as a means of formally, technically stating it as an element in the current economic situation, that doctrine and all its works are altogether idle. The like is true for the sequence of change that is going forward in the pecuniary relations of modern life; the hedonistic postulate and its propositions of differential utility neither have served nor can serve an inquiry into these phenomena of growth, although the whole body of marginal-utility economics lies within the range of these pecuniary phenomena. It has nothing to say to the growth of business usages and expedients or to the concomitant changes in the principles of conduct which govern the pecuniary relations of men, which condition and are conditioned by these altered relations of business life or which bring them to pass. It is characteristic of the school that wherever an element of the cultural fabric, an institution or any institutional phenomenon, is involved in the facts with which the theory is occupied, such institutional facts are taken for granted, denied, or explained away. If it is a question of price, there is offered an explanation of how exchanges may take place with such effect as to leave money and price out of the account. If it is a question of credit, the effect of credit extension on business traffic is left on one side and there is an explanation of how the borrower and lender cooeperate to smooth out their respective income streams of consumable goods or sensations of consumption. The failure of the school in this respect is consistent and comprehensive. And yet these economists are lacking neither in intelligence nor in information. They are, indeed, to be credited, commonly, with a wide range of information and an exact control of materials, as well as with a very alert interest in what is going on; and apart from their theoretical pronouncements the members of the school habitually profess the sanest and most intelligent views of current practical questions, even when these questions touch matters of institutional growth and decay.