It is a great fault of symbolic pseudo-mathematical methods of formalizing a system of economic analysis…that they expressly assume strict independence between the factors involved and lose all their cogency and authority if thishypothesis is disallowed; whereas, in ordinary discourse, where we are not blindly manipulating but know all the time what we are doing and what thewords mean, we can keep ‘at the back of our heads’ the necessary reservesand qualifications and the adjustments which we still have to make later on,in a way 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, asimprecise as the initial assumptions they rest upon, which allow the authorto lose sight of the complexities and interdependencies of the real world in a maze of pretentious and unhelpful symbols.(Keynes 1936:186)