This book argues that tort law's primary obligations address a domain of basic justice and that its rhetoric of reasonableness implies a distinctive morality of mutual right and responsibility. Modern tort law is preoccupied with, and responds to, the special moral significance of harm. That special significance sometimes justifies standards of precaution more stringent than those prescribed by efficiency. This book also examines the regulatory and administrative institutions with which the common law of torts cooperates and competes, treating these as part of a continuum of institutions that instantiate the primary role pursued by modern tort law - that is, to protect our physical integrity and other essential interests from impairment and interference by others, and to do so terms that all those affected might accept as justifiable.