An exposition of the moral philosophy of Kant, Arendt and Mill Emmanuel Kant adheres to deontological ethics. His theory offers a vision of morality based on the principle of good will and duty. According to him, people can perform good deeds only with good intentions, without any consideration for the consequences. Furthermore, one must respect the laws and the categorical imperative to act in accordance with duty. Several other philosophers, such as Hannah Arendt, discuss Kant's moral philosophy. In her case study, "The Defendants and the Duties of a Law-Abiding Citizen," Arendt examines how Adolf Eichmann's actions conformed to Kant's moral precepts, but also how they ran counter to his conception of duty. In contrast, John Stuart Mill takes a teleological view of moral philosophy. He outlines his view of consequentialism and utilitarianism to argue that an action is only morally right to the extent that it maximizes the overall happiness of all parties involved, regardless of the motive. In this article, I will outline Kant's moral precepts and the importance of duty in his ethical principles. Next, I will evaluate Arendt's report on Adolf Eichmann to analyze how his actions were consistent or contrary to Kant's moral philosophy. I will conclude my discussion with an evaluation of Mill's approach to morality in order to examine the differences between his teleological philosophy and Kant's ethical principles. Kant's moral philosophy is based on the categorical imperative (CI), good will and duty. According to the IC, it is an absolute necessity, a commandment that humans must conform to universalizable maxims to treat people as ends in themselves and exercise their will without regard for the consequences or conditions of their actions. ...... middle of paper ......The three philosophers all have different ways of analyzing and perceiving ethical principles. They all base their views on different concepts of morality. Kant's deontological ethics is based on the concepts of duty, categorical imperative and good will. Similarly, Arendt uses Kant's categorical imperative and idea of ​​duty to share her account of the trial of Adolf Eichmann. She recognizes that although Eichmann was trying to live according to a Kantian definition of duty, his behavior did not correspond to Kant's moral precepts. Mill, on the other hand, advocates a teleological philosophy and uses the concept of consequentialism and utilitarianism to argue against Kant's morality. Regardless, all three philosophers contribute thoughtful ethical philosophical concepts that offer new ways to analyze moral conflicts..