noun
optimism (as a doctrine or theory)
Refers to the philosophical stance or theory that the world is fundamentally good or that things will turn out well. Often used in contrast to 厭世論 (pessimism).
See also: 楽天主義
彼の楽天論は、どんな困難な状況でも希望を失わない。
His optimism never loses hope even in the most difficult situations.
楽天論と厭世論は、哲学の歴史で対立する二つの世界観だ。
Optimism and pessimism are two opposing worldviews in the history of philosophy.
The direct antonym, meaning pessimism as a doctrine.
Compound of 楽天 (optimistic, from 楽 'enjoy' and 天 'heaven') and 論 (theory, discourse). The exact historical derivation is uncertain, but it follows the pattern of philosophical terms ending in 論.