The Doctrine of Signatures

Matthew Capowski

Staff member
This thread will be used to organize information about the doctrine of signatures.

Matthew Wood has a 5 page PDF document on the doctrine of signature titled The Doctrine of Signatures: A Guide to the Essence of Plant Properties

From the above article:

One of the ancient methods used to determine the properties of plants is the “doctrine of signatures.” The basic idea is that the plant looks like the tissue, organ or disease for which it is remedial. For example, celandine (Chelidonium majus) has a bright yellow sap. As far as I am aware, there is no other plant in temperate North America or Europe which has such a sap (except for a closely related cousin), so this attribute is quite unique -- it is a “signature” or “sign” showing how the plant may be used. Since the bile made in the liver, secreted by the gall bladder and used to emulsify fats in the intestines is yellow in color the ancients decided that this unique plant must be for bile. Indeed, down to the 1950s Chelidonium was official in the U. S. Pharmacopoeia as a remedy for congestion of the liver and gall bladder.

Both this remedy and the concept of gall bladder congestion have now been forgotten by modern medicine but celandine is still used in herbalism for swelling of the liver and gall bladder. I myself once treated a case of hepatitis C with Chelidonium so successfully that the blood test and the biopsy could find no sign of the virus. The doctor declared it a “miracle” rather than giving the herb any credit.

The doctrine of signatures is one of the articles of traditional herbalism which is most misunderstood by modern researchers. The idea that the shape or color of the plant should reveal its properties smacks of “magical thinking,” or “thought by association” or “analogy” rather than by reductionism and cause
and effect. In medicine the components of the plant are reduced to their smallest potent parts -- molecules -- and these are analysed for their effect on the body. No other method of understanding is acknowledged​