Charles Babbage proposed to make an automaton chess-player which should register mechanically the number of games lost and gained in consequence of every sort of move. Thus, the longer the automaton went on playing game, the more experienced it would become by the accumulation of experimental results. Such a machine precisely represents the acquirement of experience by our nervous organization.

The child which overbalances itself in learning to walk is experimenting on the law of gravity.

As a general rule, it is foolish to do just what other people are doing, because there are almost sure to be too many people doing the same thing.

It seems perfectly clear that Economy, if it is to be a science at all, must be a mathematical science. There exists much prejudice against attempts to introduce the methods and language of mathematics into any branch of the moral sciences. Most persons appear to hold that the physical sciences form the proper sphere of mathematical method, and that the moral sciences demand some other method-I know not what.

Fertility of imagination and abundance of guesses at truth are among the first requisites of discovery; but the erroneous guesses must almost of necessity be many times as numerous as those which prove well founded.

Value is the most invincible and impalpable of ghosts, and comes and goes unthought of, while the visible and dense matter remains as it was.

Repeated reflection and inquiry have led me to the somewhat novel opinion, that value depends entirely upon utility.