No deis a vuestros alumnos lecciones verbales de ninguna clase, puesto que sólo deben recibirlas de la experiencia; tampoco - Jean-Jacques Rousseau

Astronomy was born of superstition, eloquence of ambition, hatred, falsehood and flattery; geometry of avarice; physics of an idle curiosity; and even moral philosophy of human pride. Thus the arts and sciences owe their birth to our vices

It frequently happens that a villainous action does not torment us the instant we commit it, but on recollection, and sometimes even after a number of years have elapsed, for the remembrance of crimes is not to be extinguished.

Ancient politicians talked incessantly about morality and virtue; our politicians talk only about business and money. One will tell you that in a particular country a man is worth the sum he could be sold for in Algiers; another, by following this calculation, will find countries where a man is worth nothing, and others where he is worth less than nothing. They assess men like herds of livestock. According to them, a man has no value to the State apart from what he consumes in it. Thus one Sybarite would have been worth at least thirty Lacedaemonians. Would someone therefore hazard a guess which of these two republics, Sparta or Sybaris, was overthrown by a handful of peasants and which one made Asia tremble?