Why the World Must Contain Evil
The Theodicy. Gottfried Leibniz’s answer to the problem of evil.
Updated May 25, 2026 | Reviewed by Lybi Ma
Many people who have heard of Gottfried Leibniz first heard of him through Voltaire’s satirical Candide (1759), in which Leibniz is caricatured as the deluded Dr Pangloss, “the greatest philosopher of the Holy Empire,” a parody that is a hard to get past. Insofar as Leibniz is remembered, it is for holding, in the words of Voltaire, that “all is for the best in the best of all possible worlds.”
Unlike his predecessors Descartes and Spinoza, Leibniz received a university education in philosophy , even though, in his day, university philosophy amounted to little more than Aristotelian-Christian Scholasticism. In April 1661, at the age of 14, he enrolled at Leipzig University to study liberal arts. Five years later, in 1666, Altdorf University granted him a doctorate in law, along with the offer of a professorship. However, he declined the professorship, deeming, perhaps, that a university might not be the best place for an original thinker.
Still, Leibniz now had a licence to practise law. Later, in the Theodicy (1710), he would pose as God’s own attorney—to defend God against the charge of having introduced evil into the world. “Theodicy", a word that he himself coined, derives from the Greek for "vindication of God".
In 1755, nearly 40 years after Leibniz’s death, Lisbon suffered a magnitude 9 earthquake, sparking fires that led to greater devastation than the earthquake itself. Voltaire has Candide crawling through charred ruins, saying to himself, “If this is the best of all possible worlds, what can the rest be like?”
This so-called problem, or paradox, of evil has the pedigree of antiquity, having been attributed by Lactantius (d. 325 CE) to Epicurus (d. 270 BCE): God either wishes to take away evils, but cannot; or he can, but does not wish to. In the first instance, he is less than omnipotent; in the second, less than benevolent.
In his Dialogues Concerning Natural Religion (1779), David Hume eloquently restated the problem:
Epicurus’ old questions remain unanswered. Is [God] willing to prevent evil but not able? Then he is impotent. Is he able but willing? Then he is malevolent. Is he both able and willing? Whence then is evil?
In the Theodicy, Leibniz’s response to the Problem of Evil is that God, having created the best of all possible worlds, that is, the one that is simplest in theories while being richest in phenomena, does not cause evil but permits it for the greater good. Evil results indirectly or accidentally from the absence of good. Because God did not create evil, evil is not a substance and has no proper existence. What from our limited perspective appears to be evil in fact contributes to the greater goodness of Creation, like shadows in a painting which bring out its colours, or discordant notes in a piece of music which contribute to its richness.
Leibniz distinguishes between three forms of evil:
God could have created a world without minds. But although such a world would have been free from moral and natural evil (and, so, much less evil), it would not have been the best of possible worlds.
What’s more, the world, in man, carries within itself the potential for its own optimization. We can work, first, to improve ourselves, and then, to improve the world and reduce suffering. If asked, what is the meaning of life, Leibniz would reply, “To perfect God’s creation!”
Schopenhauer, that paradigm of a pessimist , riffing upon Leibniz, would remark that ours is the worst of all possible worlds.
And if it were any worse, it wouldn’t exist at all—a hypothesis that humanity seems keen to test.
Neel Burton is the author of the newly published The German Greeks: German Philosophy and the German Philosophers .
Lactantius, On the Anger of God .
David Hume, Dialogues Concerning Natural Religion.
GW Leibniz, Theodicy.
Arthur Schopenhauer, The World as Will and Representation, Volume II, Chapter XLVI.
Share this post Facebook Bluesky Linkedin Email
There was a problem adding your email address. Please try again.
By submitting your information you agree to the Psychology Today Terms & Conditions and Privacy Policy
Neel Burton, M.D. , is a psychiatrist, philosopher, and writer who lives and teaches in Oxford, England.
Get the help you need from a therapist near you–a FREE service from Psychology Today.
This article is part of the Bringwise Psychology Journal — daily insights on human behavior, mental health, and personal growth.