“It is largely because the free-thinkers, as a school, have hardly made up their minds whether they want to be more optimist or more pessimist than Christianity that their small but sincere movement has failed.”
Source: The Victorian Age in Literature (1913), Ch. II: The Great Victorian Novelists (p. 73)
Help us to complete the source, original and additional information
G. K. Chesterton 229
English mystery novelist and Christian apologist 1874–1936Related quotes
Bk. 1, Ch. "Paradox, Next Stop After the Boondocks
The Shockwave Rider (1975)

Source: Adventures of a Mathematician - Third Edition (1991), Chapter 3, Travels Abroad, p. 55

Epilogue, p. 242
Out of My Life and Thought : An Autobiography (1933)

“I’m a pessimist because of intelligence, but an optimist because of will.”
Letter from Prison (19 December 1929); also attributed to Romain Rolland.
Source: Gramsci's Prison Letters

“To the optimist, pessimists are neurotic; to the pessimist, optimists are deluded.”
Humor in Psychotherapy (2007)
Source: The Snake, the Crocodile and the Dog

“There is nothing more powerful than the made-up mind.”
TED Talk: Mind-Shifting Everest Swim, July 2010 http://www.ted.com/talks/lewis_pugh_s_mind_shifting_mt_everest_swim.html
Speaking & Features

“I'd rather be an optimist and a fool than a pessimist and right.”

“I'd rather be optimistic and wrong; than pessimistic and right.”
Source: Elon Musk Quotes https://quotepico.com/quotes?author=elon-musk