“We are growing serious, and,
Let me tell you, that's the very next step to being dull.”

Motto of the work written by Hesse, and attributed to an "Albertus Secundus"
The Glass Bead Game (1943)
Context: For although in a certain sense and for light-minded persons non-existent things can be more easily and irresponsibly represented in words than existing things, for the serious and conscientious historian it is just the reverse. Nothing is harder, yet nothing is more necessary, than to speak of certain things whose existence is neither demonstrable nor probable. The very fact that serious and conscientious men treat them as existing things brings them a step closer to existence and to the possibility of being born.

Source: Little Altars Everywhere

"The Rich Boy" (1926), paragraph 3.
Often quoted as “The rich are different.”
Quoted

From Building Blocks for Better Living, pages 65

When accused of being a self-loathing Jew; Curb Your Enthusiasm, Season 2, Episode 3, "Trick or Treat"

And I said "Right."
Spoken on the Track "The Story of Reuben Clamzo" on the album One Night.

The Marshall Plan Speech (1947)
Context: I need not tell you that the world situation is very serious. That must be apparent to all intelligent people. I think one difficulty is that the problem is one of such enormous complexity that the very mass of facts presented to the public by press and radio make it exceedingly difficult for the man in the street to reach a clear appraisement of the situation. Furthermore, the people of this country are distant from the troubled areas of the earth and it is hard for them to comprehend the plight and consequent reactions of the long-suffering peoples, and the effect of those reactions on their governments in connection with our efforts to promote peace in the world.

Concession speech, 1980 Quebec referendum, http://en.wikipedia.org/upload/b/ba/Rene_Levesque%2C_Si_je_vous_ai_bien_compris.wav ( http://archives.radio-canada.ca/politique/provincial_territorial/clips/4212/

Source: Life of Pi