How does the story of Oedipus illustrate Bernard Williams’s idea of moral luck?

Bernard Williams used the story of Oedipus to challenge the Kantian view that an individual's moral status is entirely immune to luck or contingent circumstances. While Immanuel Kant argued that moral worth depends solely on the quality of one's will, Williams contended that people are often morally vulnerable to factors beyond their control—a concept he termed moral luck.1

In the case of Oedipus, he killed his father and married his mother without knowing their identities at the time. Despite his lack of malicious intent or knowledge, Williams argued that Oedipus is not relieved of guilt for these actions. By highlighting this, Williams illustrated that our moral lives are deeply affected by contingencies, rejecting the idea that morality can be fully insulated from the unpredictable and often tragic nature of human existence.12