Best of all possible worlds

The phrase “the best of all possible worlds” (French: le meilleur des mondes possibles; German: Die beste aller möglichen Welten) was coined by the German polymath and Enlightenment philosopher Gottfried Leibniz in his 1710 work Essais de Théodicée sur la bonté de Dieu, la liberté de l'homme et l'origine du mal (Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil). The claim that the actual world is the best of all possible worlds is the central argument in Leibniz's theodicy, or his attempt to solve the problem of evil.

Leibniz outlined his perfect world theory in his work The Monadology, stating the argument in five statements:

God has the idea of infinitely many universes.
Only one of these universes can actually exist.
God's choices are subject to the principle of sufficient reason, that is, God has reason to choose one thing or another.
God is good.
Therefore, the universe that God chose to exist is the best of all possible worlds.

Source:

https://en.wikipedia.org/wiki/Best_of_all_possible_worlds