It is very commonly urged, that the failing supply of coal will be met by new modes of using it efficiently and economically. ...It is wholly a confu… - William Stanley Jevons

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. There are a multitude of allied branches of knowledge connected with mans condition; the relation of these to political economy is analogous to the connexion of mechanics, astronomy, optics, sound, heat, and every other branch more or less of physical science, with pure mathematics.

PLEASURE and pain are undoubtedly the ultimate objects of the calculus of economics. To satisfy our wants to the utmost with the least effort - to procure the greatest amount of what is desirable at the expense of the least that is undesirable - in other words, to maximize pleasure, is the problem of economics.

Over-production is not possible in all branches of industry at once, but it is possible in some as compared to others.