Responsibility is a key concept in our moral, social and political thinking, but is not itself properly understood. In this book J R Lucas elucidates it in terms of answerability - the obligation to answer the question 'Why did you do it?' He develops this account to include negative responsiblity - 'Why did you not do something about it?' - and share responsibility, which together yield the rationale of political responsibility. In disentangling these two strands of argument, he points out potential conflicts between them within our ideal of responsible government. He exposes the flaws in consequentialism generally, and the utilitarian theory of punishment in particular, and argues for the insights of retributive theories but without the vindictiveness. He devotes separate chapters to rewards, money and personal relations, outlines the fundamental principles of business and professional ethics, and finally touches on those issues that go beyond responsibility altogether.