A man of Seville is shaved by the Barber of Seville if and only if the man does not shave himself. Does the barber shave himself?

The resistance to a new idea increases by the square of its importance.

Science, by itself cannot, supply us with an ethic.

The psychology of adultery has been falsified by conventional morals, which assume, in monogamous countries, that attraction to one person cannot coexist with affection for another. Everybody knows that this is untrue.

The degree of one's emotions varies inversely with one's knowledge of the facts - the less you know the hotter you get.

Experience has taught me a technique for dealing with such people [...] I counter the devotees of the Great Pyramid by adoration of the Sphinx; and the devotee of nuts by pointing out that hazelnuts and walnuts are as deleterious as other foods and only Brazil nuts should be tolerated. But when I was younger I had not yet acquired this technique, with the result that my contacts with cranks were sometimes alarming.

If two hitherto rival football teams, under the influence of brotherly love, decided to co-operate in placing the football first beyond one goal and then beyond the other, no one's happiness would be increased