Experience

Experience is a mental act on the part of thinking and acting men.

The Ultimate Foundation of Economic Science, p. 15

Experience tells us something we did not know before and could not learn but for having had the experience.

The Ultimate Foundation of Economic Science, p. 18

No thinking and no acting would be possible to man if the universe were chaotic, i.e., if there were no regularity whatever in the succession and concatenation of events. In such a world of unlimited contingency. . . . There would be no possibility for man to expect anything. All experience would be merely historical, the record of what has happened in the past. No inference from past events to what might happen in the future would be permissible.

The Ultimate Foundation of Economic Science, pp. 19–20

New experience can force us to discard or modify inferences we have drawn from previous experience.

Epistemological Problems of Economics, p. 27