A book which, above all others in the world, should be forbidden, is a catalogue of forbidden books. - Georg Christoph Lichtenberg

One is rarely an impulsive innovator after the age of sixty, but one can still be a very fine orderly and inventive thinker. One rarely procreates children at that age, but one is all the more skilled at educating those who have already been procreated, and education is procreation of another kind.

Delight at having understood a very abstract and obscure system leads most people to believe in the truth of what it demonstrates.

El hombre tenía tal entendimiento que ya casi no servía para nada.