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.

Newton was a judaic monotheist of the school of Maimonides

Galton's eccentric, sceptical, observing, flashing, cavalry-leader type of mind led him eventually to become the founder of the most important, significant and, I would add, genuine branch of sociology which exists, namely eugenics.

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

The old saying holds. Owe your banker �1000 and you are at his mercy; owe him �1 million and the position is reversed.

As time goes on, I get more and more convinced that the right method in investment is to put fairly large sums into enterprises which one thinks one knows something about and in the management of which one thoroughly believes. It is a mistake to think that one limits one's risk by spreading too much between enterprises about which one knows little and has no reason for special confidence. . . . One's knowledge and experience are definitely limited and there are seldom more than two or three enterprises at any given time in which I personally feel myself entitled to put full confidence.

Ideas shape the course of history.