“Too busy with the crowded hour to fear to live or die.”
Quatrains, Nature
Bartlett's Familiar Quotations, 10th ed. (1919)
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Ralph Waldo Emerson 727
American philosopher, essayist, and poet 1803–1882Related quotes

Press conference (5 September 1972), also quoted in Paranoia & Power : Fear & Fame of Entertainment Icons (2007) by Gene N Landrum, p. 60

Johnny Got His Gun (1938)
Context: Just say "mister I'm sorry, I got no time to die, I'm too busy" and then turn and run like hell. If they say coward why don't pay any attention because it's your job to live not to die. If they talk about dying for principles that are bigger than life, you say "mister you're a liar. Nothing is bigger than life". There's nothing noble in death. What's noble about lying in the ground and rotting? What's noble about never seeing the sunshine again? What's noble about having your legs and arms blown off? What's noble about being an idiot? What's noble about being blind and deaf and dumb? What's noble about being dead? Because when you're dead, mister, it's all over. It's the end. You're less than a dog, less than a rat, less than a bee or an ant, less than a white maggot crawling around on a dungheap. You're dead, mister, and you died for nothing.

“People who are busy and happy don’t write diaries; they are too busy living.”
Source: Friday (1982), Chapter 33 (p. 353)

“It's better to die laughing than to live each moment in fear.”
“Business today consists in persuading crowds.”
Book II, Chapter V.
Crowds (1913)

Not by Twain, but from Edward Abbey's A Voice Crying In The Wilderness (1989).
Misattributed