In Chapter 2, Section 7, Keynes summarizes the chapter so far by framing the classical theory of production and value as depending on three suppositions. First, that the real wage tends to equal the marginal disutility of labor, even as money wages fluctuate in purchasing power. Second, that involuntary unemployment does not exist in the strict sense, because it would involve real wages decoupling from the marginal disutility of labor (see Chapter 2, Section IV). Third, that the aggregate supply price and the aggregate demand price for a given output of production are, or perhaps tend to be, equal.