distortions as part of the economic fabric and advocated different policy measures which (as a separate consideration) had social consequences which he personally found congenial and which he expected his readers to see in the same light. The distortions which have prevented wage levels from adapting downwards have lain in employment contracts being expressed in monetary terms; in various forms of legislation such as the minimum wage and in state-supplied benefits; in the unwillingness of workers to accept reductions in their income; and in their ability through unionisation to resist the market forces exerting downward pressure on them. Keynes accepted the classical relation between wages and the marginal productivity of labour, referring to it on page 5 as the "first postulate of classical economics" and summarising it as saying that "The wage is equal to the marginal product of labour". The first postulate can be expressed in the equation y'(N) = W/p, where y(N) is the real output when employment is N, and W and p are the wage rate and price rate in money terms (and hence W/p is the wage rate in real terms). A system can be analysed on the assumption that W is fixed (i.e. that wages are fixed in money terms) or that W/p is fixed (i.e. that they are fixed in real terms) or that N is fixed (e.g. if wages adapt to ensure full employment). All three assumptions had at times been made by classical economists, but under the assumption of wages fixed in money terms the 'first postulate' becomes an equation in two variables (N and p), and the consequences of this had not been taken into account by the classical school. Keynes proposed a 'second postulate of classical economics' asserting that the wage is equal to the marginal disutility of labour. This is an instance of wages being fixed in real terms. He attributes the second postulate to the classics subject to the qualification that unemployment may result from wages being fixed by legislation, collective bargaining, or 'mere human obstinacy' (p6), all of which are likely to fix wages in money terms. Outline of Keynes's theory Keynes's economic theory is based on the interaction between demands for saving, investment, and liquidity (i.e. money). Saving and investment are necessarily equal, but different factors influence decisions concerning them. The desire to save, in Keynes's analysis, is mostly a function of income: the wealthier