Logic should no longer be considered an elegant and learned accomplishment; it should take its place as an indispensable study for every well-informe… - William Stanley Jevons

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.

I shall endeavor to show that induction is really the inverse process of deduction.

Aristotle's dictim... may then be formulated somewhat as follows:—Whatever is known of a term may be stated of its equal or equivalent. Or, in other words, Whatever is true of a thing is true of its like. ...the value of the formula must be judged by its results; ...it not only brings into harmony all the branches of logical doctrine, but... unites them in close analogy to the corresponding parts of mathematical method. All acts of mathematical reasoning may... be considered but as applications of a corresponding axiom of quantity...