Mohr v. Williams, 95 Minn. 261, 104 N.W. 12 (Minn. 1905)
Mohr v. Williams is a foundational torts case on medical battery and the scope of patient consent.
Does a physician commit a battery by performing, without the patient's express consent, a different surgical procedure than the one authorized while the patient is under anesthesia, when no true emergency prevents obtaining consent?
A medical procedure performed without the patient's consent constitutes a battery unless circumstances amounting to an emergency make it necessary to act immediately to preserve the patient's life or health and obtaining consent is impracticable. Consent must be to the particular operation performed; good faith, due care, and the operation's potential benefit do not excuse the lack of consent. The emergency (necessity) exception applies only where delay to obtain consent would involve serious risk.
Yes. Absent a genuine emergency preventing the obtaining of consent, a physician who performs a materially different operation than the one authorized commits a battery. The court reversed and ordered a new trial because the jury instructions did not adequately submit the emergency/necessity defense, but it affirmed the governing principle that unauthorized surgery is unlawful unless justified by true necessity.
Mohr v. Williams is a cornerstone case in medical battery and the doctrine of informed consent. It teaches that consent is operation-specific and sets the template for the emergency exception that later cases and statutes adopt. For law students, the case illustrates the intersection of intentional tort principles (battery), patient autonomy, and policy-based defenses (necessity). It also highlights the importance of precise jury instructions where defenses like emergency may apply, and it foreshadows the later evolution from bare consent to informed-consent requirements.