Which of the following statements about Paracelsus is true?

• A. He discovered penicillin.
• B. He wrote De Morbis Artificium.
• C. He coined the phrase 'The dose makes the poison'.
• D. He is considered the father of occupational medicine.

Answer: (C)

The main idea being tested is how the amount of a substance determines its effect—a foundational concept in toxicology and pharmacology. Paracelsus is traditionally credited with the statement that the dose makes the poison, meaning any substance can be toxic at a high enough dose and harmless at a low dose. This perspective shifted thinking from labeling substances as simply “poison” or “safe” to understanding risk in relation to exposure and dosage, and it underpins modern medicine, poison control, and regulatory dose guidelines.

He also explored health effects related to work environments and described occupational diseases in his writings, such as De Morbis Artificum. However, the famous attribution that he is the father of occupational medicine is more commonly given to Ramazzini.

The other statements are incorrect for these reasons: penicillin was discovered by Alexander Fleming, not Paracelsus; and while Paracelsus did work on diseases of workers, the specific title in the option uses an incorrect form of the Latin title, whereas the dose-makes-the-poison idea is the enduring, distinguishing claim associated with him.