tranquillite

Heraclitus wept whenever he went out in public, and Democritus laughed: the one thought all our behavior pitiful, the other silly. We ought to take the lighter view of these things and cultivate tolerance; it is more civilized to laugh at life than to lament over it. 

Further, the man who laughs at the human race deserves more gratitude than the man who mourns over it, for he allows it hope of amelioration, whereas the foolish weeper despairs of the possibility of improvement.

—  Lucius Annaeus SenecaDe Tranquillitate Animi (On the tranquility of the mind)