---
title: "Doctrine of signatures"
chunk: 2/2
source: "https://en.wikipedia.org/wiki/Doctrine_of_signatures"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:10:52.473646+00:00"
instance: "kb-cron"
---

It is worth noting that it is possible that these are post hoc attributions—the appearance and treatment linked after the medicinal property was discovered. Depending on the article, remedies connected to the doctrine vary in number and consistency.

== Scientific, spiritual, and social context ==
Signatures are often described as post hoc attributions and mnemonics used to remember the properties of a plant rather than the reason it was originally used. There is no scientific or historical evidence that plant shapes and colors have aided in the discovery of their medical uses.
In Europe, the idea of doctrine of signatures was linked with Christian beliefs. However, similar theories were created within black magic with sympathetic magic. Similar theories have been observed all over the world in ancient Egypt, China, pre-Columbian America, and the Middle East. This can also explain how varied, and at times contradictory, applications of the doctrine can be because traditional botany is subject to optimal foraging theory. Remedies would, in many cases, be based on the environmental availability of that resource rather than its objective effectiveness.
Some sociologists frame the doctrine of signatures as a type of "enchantment", the idea that it is not just what one observes but how they observe it, and it was a device used to elevate a group of "elite" observers who could interpret the world with more accuracy. In this context, the elite observers would be those that, for example, notice that lungwort's leaves look like lung tissue rather than positing that the dark red flowers could look like blood clots or the pink petals like irritated skin. The idea being that within many descriptors, the "correct" one that links to the signature could only be found by someone within this elite group.
There are similar yet conflicting theories like the theory of opposites, where Galen supposed that a cold and wet thing could be used to treat an imbalance in a hot and dry organ. Hypotheses like these and the questions they posed, regardless of the validity of the hypotheses themselves, inspired scientific investigations into the safety and usefulness of many plant-based remedies.

== In literature ==
The phrase "signatures of all things" appears in the beginning of episode three in James Joyce's novel Ulysses. The character Stephen Dedalus is walking along the beach, thinking to himself, "Signatures of all things I am here to read, seaspawn and seawrack, the nearing tide, that rusty boot". The Canadian poet Anne Szumigalski, 1922–1999, entitled her third full-length collection Doctrine of Signatures.

== See also ==
Table of magical correspondences
Sympathetic magic
Naturalistic fallacy
Pictogram

== References ==
Citations

Bibliography

== Further reading ==
Boehme, Jakob (1651) Signatura Rerum (The Signature of All Things). Gyles Calvert.
--- Translation by J. Ellistone.
Buchanan, Scott Milross (1938) The doctrine of signatures: a defense of theory in medicine.
Cole, W. (1657) Adam in Eden or Nature's Paradise. J Streater for Nathanial Brooke.
Conrad, L.I.; M Neve, V Nutton and R Porter (1995). The Western Medical Tradition, 800 BC – 1800 AD. Cambridge University Press.
Porter, Roy (1997) The Greatest Benefit to Mankind: A Medical History of Humanity from Antiquity to the Present. HarperCollins.