Mark Twain, in defense of the role of the humorist, from a letter to the President of Yale University in 1888, which institution was about to grant him an honorary master of arts degree (in 1901, they gave him an honorary doctorate, I believe):
A friendly word was needed in our defense [“the guild of American ‘funny men'”], and you have said it, and it is sufficient. It could not become us — we being in some ways, and at intervals, modest, like other folk — to remind the world that ours is a useful trade, a worthy calling; that with all its lightness and frivolity it has one serious purpose, one aim, one specialty, and it is constant to it — the deriding of shams, the exposure of pretentious falsities, the laughing of stupid superstitions out of existence; and that whoso is by instinct engaged in this sort of warfare is the natural enemy of royalties, nobilities, privileges and all kindred swindles, and the natural friend of human rights and human liberties. We might with propriety say these things, and so hint that in some degree our calling is entitled to respect, but since you have rehabilitated us it is not necessary. I offer my best thanks to the corporation of Yale university for the high honor which they have conferred upon me, and am very sorry that my circumstances deny me the privilege of saying my thanks by word of mouth at the dinner tomorrow night. With great respect, I am truly yours, S. L. CLEMENS.
– letter to President Timothy Dwight, Yale University, June 26, 1888. Reprinted in Hartford Daily Courant, June 29, 1888, p. 5.<http://www.twainquotes.com/Degrees.html>
I think I shall be quoting this again very soon.