The question of moral dilemmas, despite its importance, was underestimated for a long time in moral philosophy. In this work, Guillermo Lariguet proposes to offer an introduction to problems of evident philosophical relevance and practical consequences relating to the nature of the limits of reasoning practices and to the range of principles of deontic logic, such as that of consistency and "should implies could," which is useful for both the philosopher and the layperson. He also discusses themes linked to the conceptual statute of the incommensurability of values and the link between conflicts and moral pluralism. Besides offering an approximation to the challenge of this dilemma, the book presents multiple examples of how moral theories have tried to deal with these situations which, on occasion, can be very tragic in nature when inevitable evils are present within them.