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.

The Doctrine of Signatures: Reading the Signs of Nature by Sarah Baldwin:

The Doctrine of Signatures in the Medieval and Ottoman Levant by Efraim Lev