Irving Caesar (1895–1996) American composer and lyricist
This is actually James Branch Cabell from The Silver Stallion (1926)
Misattributed
Coth, in Book Four : Coth at Porutsa, Ch. XXVI : The Realist in Defeat
Source: The Silver Stallion (1926)
Context: Yet creeds mean very little... The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true. So I elect for neither label.
Irving Caesar (1895–1996) American composer and lyricist
This is actually James Branch Cabell from The Silver Stallion (1926)
Misattributed
“The Optimist thinks this is the best of all possible worlds, the Pessimist fears it is true.”
Robert Oppenheimer (1904–1967) American theoretical physicist and professor of physics
This is derived from a statement of James Branch Cabell, in The Silver Stallion (1926) : The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true.
Misattributed
Variant: The optimist thinks this is the best of all possible worlds. The pessimist fears it is true.
Ivar Ekeland (1944) French mathematician
Introduction, p. 1.
The Best of All Possible Worlds (2006)
Shimon Peres (1923–2016) Israeli politician, 8th prime minister and 9th president of Israel
As quoted in Serving "60 Years to Life", Newsweek Europe (12 December 2005)
José Saramago (1922–2010) Portuguese writer and recipient of the 1998 Nobel Prize in Literature
ÉPOCA Interview (in Portuguese) http://revistaepoca.globo.com/Epoca/0,6993,EPT1061569-1666-2,00.html, São Paulo, 2005.
“I'm a pessimist about probabilities, I'm an optimist about possibilities.”
Lewis Mumford (1895–1990) American historian, sociologist, philosopher of technology, and literary critic
As quoted in "Lewis Mumford Remembers" by Carey Winfrey in The New York Times (6 July 1977)
“To the optimist, pessimists are neurotic; to the pessimist, optimists are deluded.”
David H. Levy (1948) Canadian astronomer
Humor in Psychotherapy (2007)
“[…] You see, you are an optimist and live on hope. I am a pessimist and live on experience.”
Malcolm Bradbury (1932–2000) English author and academic
Page 352-353.
Stepping Westward (1965)
Max Lerner (1902–1992) American journalist and educator
Lerner's summary of his life for "Who's Who in America," quoted in Max Lerner, Writer, 89, Is Dead; Humanist on Political Barricades By Richard Severo, The New York Times, https://www.nytimes.com/1992/06/06/arts/max-lerner-writer-89-is-dead-humanist-on-political-barricades.html (6 June 1992)