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

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

It is clear that economics, if it is to be a science at all, must be a mathematical science.

Many persons entertain a prejudice against mathematical language, arising out of a confusion between the ideas of a mathematical science and an exact science. ...in reality, there is no such thing as an exact science.

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.

You will perceive that economy, scientifically speaking, is a very contracted science; it is in fact a sort of vague mathematics which calculates the causes and effects of man's industry, and shows how it may be best applied.

Science arises from the discovery of Identity amid Diversity.