the theory that nature has put a mark or ‘signature’ on every natural object, providing a clue to the ‘virtue’ or property contained within that object. These signs were perceived to be woven into the tapestry of nature by the hand of God
Abraham defines the alchemical doctrine of signatures as a divinely inscribed hermeneutic system in which every natural object carries an outward mark that reveals its inner occult virtue.
, A Dictionary of Alchemical Imagery, 1998thesis