Man, however, is the most courageous animal: thereby hath he overcome every animal. With sound of triumph hath he overcome every pain; human pain, however, is the sorest pain.
Courage slayeth also giddiness at abysses: and where doth man not stand at abysses! Is not seeing itself—seeing abysses?
Courage is the best slayer: courage slayeth also fellow-suffering.
 Friedrich Nietzsche, Thus Spoke Zarathustra (1891). copy citation

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Author Friedrich Nietzsche
Source Thus Spoke Zarathustra
Topic pain courage
Date 1891
Language English
Reference
Note Translated By Thomas Common
Weblink http://www.gutenberg.org/files/1998/1998-h/1998-h.htm

Context

“it hath hitherto slain for me every dejection. This courage at last bade me stand still and say: “Dwarf! Thou! Or I!”— For courage is the best slayer,—courage which ATTACKETH: for in every attack there is sound of triumph. Man, however, is the most courageous animal: thereby hath he overcome every animal. With sound of triumph hath he overcome every pain; human pain, however, is the sorest pain. Courage slayeth also giddiness at abysses: and where doth man not stand at abysses! Is not seeing itself—seeing abysses? Courage is the best slayer: courage slayeth also fellow-suffering. Fellow-suffering, however, is the deepest abyss: as deeply as man looketh into life, so deeply also doth he look into suffering. Courage, however, is the best slayer, courage which attacketh: it slayeth even death itself;” source