Recent reexaminations of the principles of tort liability have entertained two possible
rationales for the fault principle, one "moral" and the other economic. Neither is satisfactory.
I propose here a third rationale and show how it suffices to refute at least some of the
challenges to the negligence system. The character of this rationale is causal, and the central
thesis of this paper is that in as much as the tort system should aim to place the costs of
accidents on the source of those accidents, then we have not yet found an acceptable
alternative to the negligence system. This thesis is defended and developed through a
reexamination of some recent theories of strict liability and reflection on some of what has
been said about the role of causation in torts. A backdrop to the entire discussion is the
question of how one might best ensure that potential defendants will be able to predict with
reasonable certainty which courses of action will make them liable, should damages ensue
