OPTIMISM

n. state of seeing the good in life, state of hoping for the best

Optimism is an outlook on life such that one maintains a view of the world as a positive place. It is the opposite of pessimism. Optimists generally believe that people and events are inherently good, so that most situations work out in the end for the best.A common conundrum illustrates optimism-versus-pessimism with the question, does one regard a given glass of water, filled to half its capacity, as half full or as half empty? Conventional wisdom expects optimists to reply, "Half full," and pessimists to respond, "Half empty" (assuming that "full" is considered good, and empty, "bad").
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Optimism, n attitude cultivated by an individual in which he or she believes in the positive resolution of a stressful event. [more]Optimism - Community and Resources

Noun
1. the optimistic feeling that all is going to turn out well
(antonym) pessimism
(hypernym) hope
(hyponym) sanguinity, sanguineness
2. a general disposition to expect the best in all things
(antonym) pessimism
(hypernym) disposition, temperament

(n.)
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.
  

(n.)
A disposition to take the most hopeful view; -- opposed to pessimism.