The core of late twentieth century economics consists of a set of assumptions which, taken together and seen as a whole, constitutes an image or vision of a self-regulating system in which friction and inertia are largely absent. Friction in both senses of the word is generally ignored: there is neither dissention and conflict nor is there resistance to relative motion. The economic system adjusts smoothly to disturbances; markets clear instantaneously; competition ensures that resources are used efficiently. We live, in effect, in the best of all possible worlds given the resources and technology available to us and the distribution of income.