  Jevons seems to be a mathematical, deductive economist. Market prices are derived directly from a series of fundamental motive forces, such as “the mechanics of utility and self-interest”. Markets are depicted in the most abstract fashion and economic agents are perfectly rational, perfectly foresighted and in possession of perfect information. A perfectly rational human being would anticipate future feelings and include discounted future utility in his calculations. However, this ability varies according to certain circumstances, as there are “the intellectual standing of the race, or the character of the individual” (Jevons 1879: 34). The ability of foresight depends on the state of civilisation: the class or race with the most foresight will work most for the future, because a powerful feeling for the future is the main incentive to industry and saving. Moreover, even the ‘quality’ of tastes increases with every improvement of civilisation. Jevons' conception of an economic agent should therefore be altered according to the institutional setting in which the agent appears (the class or race to which the individual belongs).