optimism: [18] Etymologically as well as semantically, optimism means hoping for ‘the best’. It was coined in French (as optimisme) in 1737 as a term for the doctrine of the German philosopher Leibnitz (1646–1716) that the world is as good as it could possibly be. It was based on Latin optimum (source also of English optimum [19]), the neuter case of optimus ‘best’. This may have been formed from the preposition ob ‘in front of’ and a superlative suffix. [optimism etymology, optimism origin, 英语词源]