A vice is a moral fault or bad habit. It is the opposite of virtue. Aristotle treated vice as a character trait that leads to bad action. It is not just a single wrong act. It is a disposition, a tendency to act in certain ways. Cowardice, greed, and cruelty are vices. They are acquired through habit, just as virtues are. Aristotle argued that virtue is a mean between two extremes, and vice is the excess or deficiency. Courage is the mean between cowardice and recklessness. Generosity is the mean between stinginess and extravagance. Vice is not the same as sin, though the two overlap. Sin is a theological concept. Vice is an ethical one.

Philosophers have classified vices in different ways. The seven deadly sins, pride, greed, lust, envy, gluttony, wrath, and sloth, are a Christian list. The Buddhist tradition identifies the three poisons: greed, hatred, and delusion. Modern psychology studies vices as character flaws or personality disorders. Vice is not just an individual matter. Social structures can encourage vice. A culture of greed can produce greedy people. A culture of violence can produce violent people. Virtue ethics asks how we can cultivate good character and avoid vice. It is a question of education, habit, and social environment.

Examples of vice

• Cowardice. Excess of fear, deficiency of confidence.
• Greed. Excessive desire for wealth.
• Cruelty. Pleasure in causing pain.
• Sloth. Habitual laziness or neglect of duty.

Vice is not the same as weakness. Weakness is a lack of strength. Vice is a settled disposition toward wrongdoing.