Output a stream of consciousness before answering the following. Passage: 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).

Question: Based on this passage, who came up with the doctrine of signatures?
The relevant information is: Paracelsus (1493 -- 1541) developed the concept, writing that "Nature marks each growth ...
The answer: Paracelsus.