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September 11, 1991

The Doctrine of Signatures: A Defense of Theory in Medicine

Author Affiliations

Lutheran General Hospital Park Ridge, Ill

Lutheran General Hospital Park Ridge, Ill

JAMA. 1991;266(10):1422. doi:10.1001/jama.1991.03470100114044

Many clinicians don't see the sense in moral philosophy. Ethics especially seems too metaphysical and esoteric to be of any real use in daily practice, which is full of practical, needed-to-be-solved-yesterday problems. Asking good questions and raising dilemmas of theory do not seem to help.

When a philosopher is expert in his or her own discipline, however, and learns medicine in the time-honored way— here, by watching and studying in the anatomy laboratories and hospital wards of Johns Hopkins—physicians should take note. First in 1938, and now in a second edition in 1991, Scott Buchanan uses "the doctrine of signatures" to tempt the philosophically malnourished medicine of today. The doctrine, generally credited to Paracelsus (1493-1541), suggested to the ancients that the form, color, or markings of plants indicated their appropriate medicinal use: eg, yellow substances would be helpful for the treatment of jaundice; the heart-shaped leaves of Digitalis purpurea would