I have received, sir, your new book against the human species, and I thank you for it. You will please people by your manner of telling them the truth about themselves, but you will not alter them. The horrors of that human society—from which in our feebleness and ignorance we expect so many consolations—have never been painted in more striking colours: no one has ever been so witty as you are in trying to turn us into brutes: to read your book makes one long to go on all fours. Since, however, it is now some sixty years since I gave up the practice, I feel that it is unfortunately impossible for me to resume it: I leave this natural habit to those more fit for it than are you and I.

The king [Frederic] has sent me some of his dirty linen to wash; I will wash yours another time.

If there were only one religion in England there would be danger of despotism, if there were two they would cut each other's throats, but there are thirty, and they live in peace and happiness.

Go into the London Stock Exchange – a more respectable place than many a court – and you will see representatives from all nations gathered together for the utility of men. Here Jew, Mohammedan and Christian deal with each other as though they were all of the same faith, and only apply the word infidel to people who go bankrupt. Here the Presbyterian trusts the Anabaptist and the Anglican accepts a promise from the Quaker.

If I had had more time, this letter would have been shorter.

The best government is a benevolent tyranny tempered by an occasional assassination.

The adjective is the enemy of the substantive.

I cannot imagine how the clockwork of the universe can exist without a clockmaker.

It is forbidden to kill; therefore all murderers are punished unless they kill in large numbers and to the sound of trumpets.

Nothing is so common as to imitate one's enemies, and to use their weapons.