Health care has increasingly come to be understood as a commodity. The ethical implications of such an understanding are significant. The author argues that health care is not a commodity because health care (1) is non-proprietary, (2) serves the needs of persons who, as patients, are uniquely vulnerable, (3) essentially involves a special human relationship which ought not be bought or sold, (4) helps to define what is meant by 'necessity' and cannot be considered a commodity when subjected to rigorous conceptual analysis. The Oslerian conception that medicine is a calling and not a business ought to be reaffirmed by both the profession and the public. Such a conception would have significant ramifications for patient care and health care policy.