f God, the Freedom of Man and the Origin of Evil. Or more simply known as Theodicy, is a philosophical work by the German polymath Gottfried Wilhelm Leibniz. The work, first published in 1710, birthed the term "theodicy", and its optimistic approach to the problem of evil is thought to have inspired Voltaire's Candide, in a satirical manner. Most of the work consists of a response to the ideas of the French philosopher Pierre Bayle, with whom Leibniz carried on a debate for many years.