Defenses to Negligence Introduction Read the overview below and complete the activities that follow. The courts' doctrines of res ipsa loquitur and negligence per se help the plaintiff in a negligence case, but the courts permit certain defenses that relieve the defendant from liability even when the plaintiff has proved all four elements of negligence. Defendants can successfully rebut negligence claims with contributory negligence, comparative negligence, assumption of the risk, and other special negligence defenses. CONCEPT REVIEW: Review LO 7-5 in Chapter 7. The text explains multiple defenses to negligence, including contributory negligence, comparative negligence, assumption of the risk, and other special negligence defenses. The following exercise will test your understanding of the similarities and differences between two of these defenses to negligence: contributory and comparative negligence.