The doctrine, or belief, that everything is beautiful, including what is ugly, everything good, especially the bad, and everything right that is wrong. It is held with greatest tenacity by those most accustomed to the mischance of falling into adversity, and is most acceptably expounded with the grin that apes a smile. Being a blind faith, it is inaccessible to the light of disproof -- an intellectual disorder, yielding to no treatment but death. It is hereditary, but fortunately not contagious.

The opinion or doctrine that everything in nature, being the work of God, is ordered for the best, or that the ordering of things in the universe is such as to produce the highest good.

A habitual tendency or a present disposition to take the most hopeful view of future events, and to expect a favorable outcome even when unfavorable outcomes are possible; -- opposed to pessimism.

A cheerful frame of mind that enables a tea kettle to sing though in hot water up to its nose.

the optimistic feeling that all is going to turn out well