The present study investigates three questions: 1.) What is responsibility? 2.) How can responsibility be founded? 3.) And how can one act responsibly? Responsibility is interpreted as a practice of providing answers and justification, which constitutes the core of the moral relationship to other people. The work centers on the thesis that people recognize each other and thereby realize that they are responsible for the other person, i.e. that they owe answers and good reasons to others who are affected by their actions. Responsibility as a key moral category thus does not require any external foundation, but rather is itself the ultimate ground for all justification.