We live in the best of all possible worlds.

The principle of sufficient reason holds that for everything, there must be sufficient reason why it exists. And according to Leibniz the only sufficient reason for the world we live in is that God created it as the best possible universe. God could have created a universe in which no one ever did wrong, in which there was no human evil, but that would require humans to be deprived of the gift of free wills and thus would not be the best possible world.

Voltaire’s famous novel Candide satirizes this optimistic view. And looking around you right now you may wonder how anyone could actually believe it. But Leibniz [wiki] believed that before creation God contemplated every possible way the universe could be and chose to create the one in which we live because it’s the best.a revolutionary doctrine that advocates destruction of the social system for its own sake.