Actual Causation in the Second and Third Restatements: Or, the Expulsion of the Substantial Factor Test

This chapter contrasts the Restatement (Third) of Torts: Liability for Physical Harm’s Chapter Five (on Factual Cause) and Chapter Six (on Scope of Liability) with the treatment of causation in the Restatement (Second) of Torts’ Chapter 16 (“Legal Cause”). It was written for a book on causation in both common law and civilian jurisdictions. The chapter examines in some detail the arguments that led the Reporters of the Third Restatement to reject the expression “substantial factor” and how the work done by this phrase in the domain of cause-in-fact was handled by and expanded conception but-for causation to which was added the idea of the “causal set model”, or NESS Test. The work done by the phrase “substantial factor” in the domain of proximate cause is now done by the concept of “scope of the risk” and variants of the risk rule. The chapter emphasizes the seriousness with which the Third Restatement sought to remove from the question of cause-in-fact any subjective judgment it deemed a matter of proximate cause. The chapter points argues that this focus on rendering cause-in-fact judgments purely objective, when combined with the causal set model, produces a final product where much of the normative work that was once done in causation is now pushed off into questions of apportionment.