Progress is slow partly from mere intellectual inertia. In a subject where there is no agreed procedure for knocking out errors, doctrines have a long life. A professor teaches what he was taught, and his pupils, with a proper respect and reverence for teachers, set up a resistance against his critics for no other reason than that it was he whose pupils they were.

Rosa Luxemburg maintained that the capitalist system can keep up its rate of investment (and therefore its profits) only so long as it is expanding geographically.

There is an unearthly, mystical element in Friedman's thought. The mere existence of a stock of money somehow promotes expenditure. But insofar as he offers an intelligible theory, it is made up of elements borrowed from Keynes.

New ideas are difficult just because they are new. Repetition has somehow plastered over the gaps and inconsistencies in the old ones, and the new cannot penetrate.

When I came up to Cambridge (in October 1921) to read economics, I did not have much idea of what it was about.

The nature of technology depends very much upon what the public can be induced to put up with.

Unequal distribution of income is an excessively uneconomic method of getting the necessary saving done.