# Paracelsus Paracelsus (c. 1493–1541), born Theophrastus von Hohenheim, was a Swiss physician, alchemist, and reformer often called the father of toxicology. He is remembered in the KB chiefly for the principle "the dose makes the poison" (*sola dosis facit venenum*) — the foundational insight of [[Toxicology and Dose-Response]] that any substance can be harmful or harmless depending on quantity. A boundary figure between alchemy and chemistry, he challenged the medical orthodoxy of his day and insisted on observation over received authority. > [!note] Stub > Minimum-viable page created to resolve inbound wikilinks. Expand with biography, contributions to medicine and chemistry, and the legacy of the dose-response principle. ## See Also - [[Toxicology and Dose-Response]] - The History of Biochemistry