It's relevant that Keynes doesn't condemn, here, the use of mathematics in economics (as for him, he rather liked to have recourse to them up to tautology), but that he implicitly accuses the lack of a conceptual basis in economics, so much so that "the back of the head" is nothing but a rough substitute for it. Economics aren't yet a true science, although such a tool has never been so necessary as nowadays. That's the reason why econometrics ask mathematics to fill the conceptual gap. This matter is economically the most important one, but I'm afraid it doesn't interest the most of economists... Sincerly Romain Kroes Laurence Shute wrote: > > Does this help any? From the General Theory (pp 297-98): > > "It is a great fault of symbolic pseudo-mathematical methods of formalising > a system of economic analysis, such as we shall set down in section VI of > this chapter, that they expressly assume strict independence between the > factors involved and lose all their cogency and authority if this > hypothesis is disallowed; whereas, in ordinary discourse, where we are not > blindly manipulating but know all the time what we are doing and what the > words mean, we can keep 'at the back of our heads' the necessary reserves > and qualifications and the adjustments which we shall have to make later > on, in a way in which we cannot keep complicated partial differentials 'at > the back' of several pages of algebra which assume that they all vanish. > Too large a proportion of recent 'mathematical' economics are mere > concoctions, as imprecise as the initial assumptions they rest on, which > allow the author to lose4 sight of the complexities and interdependencies > of the real world in a maze of pretentious and unhelpful symbols." > > In 1940 Keynes was greatly worried that his American disciplices "were more > orthodox than the master," in the sense that they failed to keep the > necessary reservations "at the back of their head."
