Once we allow ourselves to be disobedient to the test of an accountant's profit, we have begun to change our civilization.

If we consistently act on the optimistic hypothesis, this hypothesis will tend to be realised; whilst by acting on the pessimistic hypothesis we can keep ourselves for ever in the pit of want.

Ideas shape the course of history.

I am sure that the power of vested interests is vastly exaggerated compared with the gradual encroachment of ideas.

The importance of money flows from it being a link between the present and the future.

The power to become habituated to his surroundings is a marked characteristic of mankind.

The biggest problem is not to let people accept new ideas, but to let them forget the old ones.