The engine which drives Enterprise is not Thrift, but Profit.

Taken at face value, the line contrasts two motives often invoked to explain capitalist dynamism. “Thrift” (saving, frugality, abstinence) is a traditional moral-economic virtue associated with capital accumulation, while “profit” is the immediate inducement that prompts entrepreneurs to undertake risk, organize production, and invest. The claim implies that enterprise responds primarily to expected returns rather than to generalized habits of saving; in downturns, exhortations to thrift may even depress demand and weaken the profit outlook that stimulates investment. The emphasis aligns with Keynes’s broader concern that investment depends on expectations and incentives, not merely on the supply of savings.