Doctrine of signatures

The doctrine of signatures, dating from the time of Dioscorides and Galen, states that herbs resembling various parts of the body can be used by herbalists to treat ailments of those body parts. A theological justification, as stated by botanists such as William Coles, was that God would have wanted to show men what plants would be useful for.

Paracelsus (1493–1541) developed the concept, writing that "Nature marks each growth ... according to its curative benefit", and it was followed by Giambattista della Porta in his Phytognomonica (1588).

The writings of Jakob Böhme (1575–1624) spread the doctrine of signatures. He suggested that God marked objects with a sign, or "signature", for their purpose. Plants bearing parts that resembled human body-parts, animals, or other objects were thought to have useful relevance to those parts, animals or objects. The "signature" could sometimes also be identified in the environments or specific sites in which plants grew. Böhme's 1621 book The Signature of All Things gave its name to the doctrine. The English physician-philosopher Sir Thomas Browne in his discourse The Garden of Cyrus (1658) uses the Quincunx pattern as an archetype of the 'doctrine of signatures' pervading the design of gardens and orchards, botany and the Macrocosm at large.

The botanist William Coles (1626–1662) supposed that God had made 'Herbes for the use of men, and hath given them particular Signatures, whereby a man may read ... the use of them.' Coles's The Art of Simpling and Adam in Eden, stated that walnuts were good for curing head ailments because in his opinion, "they Have the perfect Signatures of the Head". Regarding Hypericum, he wrote, "The little holes whereof the leaves of Saint Johns wort are full, doe resemble all the pores of the skin and therefore it is profitable for all hurts and wounds that can happen thereunto."

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