The master-economist must possess a rare combination of gifts. He must reach a high standard in several different directions and must combine talents not often found together. He must be mathematician, historian, statesman, philosopher - in some degree. He must understand symbols and speak in words. He must contemplate the particular in terms of the general, and touch abstract and concrete in the same flight of thought. He must study the present in the light ofthe past for the purposes of the future

The engine which drives enterprise is not thrift, but profit.

If human nature felt no temptation to take a chance there might not be much investment merely as a result of cold calculation.

A conventional valuation which is established as the outcome of the mass psychology of a large number of ignorant individuals is liable to change violently as the result of a sudden fluctuation of opinion due to factors which do not really make much difference to the prospective yield; since there will be no strong roots of conviction to hold it steady.

[T]he theory of output as a whole, which is what the following book purports to provide, is much more easily adapted to the conditions of a totalitarian state, than is the theory of production and distribution of a given output produced under the conditions of free competition and a large measure of laissez-faire.

What an extraordinary episode in the economic progress of man that age was which came to an end in August, 1914!

When my information changes, I alter my conclusions. What do you do, sir?