This article explains the way tort law brings the fundamental questions together. It supposes that the question of how people treat each other and the question of whose problem it is when things go wrong are at bottom the same question. The main task in doing so is to explain the sense in which tort law predicates liability on responsibility. Tort law articulates norms of conduct and resolves conflicts in the context of disputes between private parties. This article begins with the two basic normative principles that tort law incorporates. The relevant notion of responsibility depends on norms of conduct, and much of the article is taken up with developing that notion and explaining why it has features that are strikingly different from other familiar conceptions. It focuses largely on responsibility in negligence, both in terms of a general structure and particular doctrines.