Among the assumptions of a hundred years ago was the premise, self-evident to that generation of thoughtful men, that the phase of commercialised economic life then prevailing was the immutably normal order of things. And the assumptions surrounding that preconception were good and competent for a formulation of economic theory that takes such an institutional situation for granted and assumes it to be unchanging, or to be a _terminus ad quem_. But for anything like a genetic account of economic life, early or late, capitalistic or otherwise, such assumptions and the theoretical propositions and analyses that follow from them are defective in that they take for granted what requires to be accounted for. Theoretical speculation that presupposes the (somewhat old-fashioned) institutions formerly governing ownership and business traffic, and assumes them to have the immutable character and indefeasible force _de facto_ which is assigned them _de jure_, and that likewise assumes as immutable a passing phase in the “state of the industrial arts,” may serve passably for a theory of how business affairs should properly arrange themselves to fit the conditions so assumed; and such, indeed, has commonly been the character of theoretical formulations touching industry and business. And as should fairly be expected, in the speculations of the economists, these theoretical formulations have also commonly been accompanied by a parallel line of remedial advice designed to show what preventive measures should be applied to prevent the run of business practice from doing violence to these assumed conditions that are held to be immutably normal and indefeasibly right.