Theory of general static equilibrium/ edited by G.L.S. Shackle

THE main types of strategy in economic thinking, the underlying philosophies and ethical attitudes of the economists, and the systems or bodies of theory which result, can no doubt be usefully classified in more than one way; but a broad division which enables us the better to see the peculiar merits of different methodologies, to allow for their particular weaknesses, and to avoid the distrac bion of trying to think in two incompatible ways at the same time, is the division between those improvising, realistic, extroverted and empirical approaches which take at its face value the apparent diversity of the world's affairs, and those others which proceed in the conviction of an essential unity at the heart of things. "The fox knows many things, but the hedgehog knows one big thing. In the luminous passage which Mr Isaiah Berlin has based upon this line from Archilochus, the hedgehog is made to symbolize the nucleistic philosopher whose whole system is the unfolding and elaboration of one powerful idea. Systems of thought in which a single principle, or a compact nucleus of mutually inter penetrating basic notions, is universally applied throughout an entire field and explains everything in it, may thus be contrasted with those where, in the extreme, a special explanatory tool is fashioned for each new phenomenon to be explained.