This lecture delves into the ethical theories of consequentialism and categorical imperative, exploring the importance of defining values, justifications, and normative principles in decision-making processes related to artificial intelligence. The instructor discusses the distinction between descriptive and normative ambitions, emphasizing the need for providing reasons and justifications for ethical decisions. The lecture also touches on the concepts of autonomy, universal values, and relativism, highlighting the challenges of defining a 'good life' and the implications for ethical decision-making. Through examples like the categorical imperative and consequentialism, the instructor illustrates how ethical theories guide moral reasoning and decision-making in complex situations.