The chief occasion for this edition is the change in the first-year curriculum in Harvard Law School, which assigned to other courses many things formerly appropriated to the course in the Law of Torts and hence treated in former editions. Thus causation is now treated in a course on the Principles of Legal Liability; certain excuses, such as consent and self-defence, are dealt with in that course, and trespass to land and conversion, which analytically might well be treated in the first c...