Good and evil

Lore & Background

Every language has a word expressing good in the sense of 'having the right or desirable quality' and bad in the sense 'undesirable'. A sense of moral judgment and a distinction between right and wrong, good and bad are cultural universals. In ancient times, the philosopher Zoroaster simplified the pantheon of early Iranian gods into two opposing forces: Ahura Mazda (Illuminating Wisdom) and Angra Mainyu (Destructive Spirit), which were in conflict. Similarly, in ancient Egypt, there were the concepts of Ma'at, the principle of justice, order, and cohesion, and Isfet, the principle of chaos, disorder, and decay. Morality in this absolute sense solidifies in the dialogues of Plato, together with the emergence of monotheistic thought. The idea was further developed in Late Antiquity by Neoplatonists, Gnostics, and Church Fathers. According to the classical definition of Augustine of Hippo, sin is 'a word, deed, or desire in opposition to the eternal law of God.'

Reader's Guide

The dichotomy of good and evil has shaped religious, philosophical, and psychological discourse across cultures. In Zoroastrianism, the world is a battleground between Ahura Mazda and Angra Mainyu, with a final Day of Judgement. In Confucianism and Taoism, there is no direct analogue to the way good and evil are opposed, though demonic influence appears in Chinese folk religion. Pyrrhonism holds that good and evil do not exist by nature but are relative to the judge. Benedict de Spinoza defined good as that which is useful to us and evil as that which hinders us from possessing anything good. Friedrich Nietzsche rejected Judeo-Christian morality, arguing that the concept of evil was socially transformed by a 'slave mentality' of the masses. In psychology, Carl Jung depicted evil as the dark side of the Devil, with people projecting their shadow onto others. Philip Zimbardo suggested that people may act in evil ways as a result of a collective identity, based on the Stanford prison experiment. The modern English word 'evil' comes from a Proto-Germanic reconstructed form *ubilaz, ultimately from Proto-Indo-European *wap-.

Did You Know?

• Every language has a word expressing good in the sense of 'having the right or desirable quality' and bad in the sense 'undesirable'.
• In ancient Egypt, Ma'at was the principle of justice, order, and cohesion, while Isfet was the principle of chaos, disorder, and decay.
• According to Augustine of Hippo, sin is 'a word, deed, or desire in opposition to the eternal law of God.'
• The modern English word 'evil' comes from a Proto-Germanic reconstructed form *ubilaz.

Historical Roots and the Epicurean Challenge

The problem of evil traces its earliest philosophical articulation to the Greek thinker Epicurus, who lived in the fourth and third centuries BCE. His formulation, later captured by David Hume in a memorable three-part question, asks whether a deity is willing but unable to stop suffering (making it impotent), able but unwilling (making it malevolent), or both able and willing (leaving the origin of evil unexplained). Remarkably, a parallel challenge appears even earlier in Buddhist scripture. In the Majjhima Nikāya, the Buddha, speaking in the sixth or fifth century BCE, observes that if a god were responsible for creating sentient beings, the pain and suffering those beings endure would make that god likely an evil one. These ancient formulations established a pattern that persists in modern philosophy: the tension between a perfectly good, all-powerful, all-knowing creator and the observable reality of harm, from epidemics and wars to natural disasters that strike innocent victims. The problem is not merely academic; it is, at its core, an experiential difficulty in maintaining faith when confronted with real-world suffering.

The Logical and Evidential Divide

Contemporary philosophy of religion typically splits the problem of evil into two distinct arguments. The logical version attempts to demonstrate a genuine conceptual contradiction: if an omnipotent, omnibenevolent, and omniscient God exists, then evil cannot exist; since evil does exist, such a God cannot exist. This is structured as modus tollens, meaning the conclusion follows with strict necessity if the premises hold. Most philosophers today consider the logical problem to have been effectively answered by various defenses that show the coexistence of God and evil is at least logically possible. The evidential problem, by contrast, takes a softer but arguably more persistent approach. It does not claim logical impossibility but rather argues that the sheer volume and character of suffering in the world makes the existence of a perfectly good, all-powerful, all-knowing deity improbable. Unlike the logical variant, the evidential argument remains a live topic of active debate among contemporary philosophers, continuing to generate new responses and refinements.

Defining Evil and the Divine Attributes

Any serious engagement with the problem of evil requires careful attention to its core vocabulary. In philosophical discussion, evil is used far more broadly than in everyday speech. Rather than reserving the word for the most heinous moral atrocities, the problem encompasses any bad state of affairs, wrongful action, or character flaw, whether natural or moral, whether a minor injustice or a catastrophic disaster. Marcus Singer offered a guiding principle: if something is truly evil, it cannot be necessary, and if it is truly necessary, it cannot be evil. The divine attributes are equally nuanced. Omniscience, in the most widely accepted twenty-first-century view, means God knows everything that is knowable, but events hinging on free human choices remain unknowable until they occur. Omnipotence is maximal power within the bounds of logical and temporal possibility, not the ability to cause contradictions or override another agent's free decision. Omnibenevolence means God acts according to what is best, or, when no single best option exists, seeks the optimal creatable state within physical constraints.

Defenses, Theodicies, and the Architecture of Response

Philosophers have traditionally organized responses to the problem of evil into two broad categories, though scholars disagree on precise boundaries. A defense is a relatively modest undertaking: it need only demonstrate that the coexistence of a perfect God and evil is logically possible, thereby defusing the logical argument's claim of strict impossibility. A defense does not have to be true, probable, or even a full explanation; it simply must show that the contradiction alleged by the logical problem does not actually hold. A theodicy, by contrast, is a far more ambitious project. It seeks to offer a morally or philosophically sufficient justification for why evil exists at all, aiming to weaken the evidential argument's claim that God's existence is improbable given the world's suffering. Theodicies attempt to make sense of suffering in a way that preserves both the reality of evil and the plausibility of a benevolent creator. Together, these two response types form the backbone of the philosophical literature, addressing the problem from its logical and evidential angles respectively.