Pessimist by policy, optimist by temperament- it is possible to be both. How? By never taking an unnecessary chance and by minimizing the risks you can't avoid. This permits you to play out the game untroubled by the certainty of the outcome.
Robert A. HeinleinThe average bloke . . . hates and fears all freedom, not only for others but for himself, and stamps it out wherever possible.
Robert A. HeinleinMorals - all correct moral laws - derive from the instinct to survive. Moral behavior is survival behavior above the individual level.
Robert A. Heinlein