Yahya Bin Ammaar Explains the Five Types of Knowledge (Which Constitute) Life, Nourishment, Medicine, Disease, and Destruction 
Posted on Monday, August 22, 2011 
Yahyaa bin Ammaar (d. 422H) said: 
العلوم خمسة علم هو حياة الدين وهو علم التوحيد وعلم هو قوت الدين وهو العظة والذكر وعلم هو دواء الدين وهو الفقه وعلم هو داء الدين وهو أخبار ما وقع بين السلف وعلم هو هلاك الدين وهو الكلام

Types of knowledge are five: Knowledge which is the 
life of the religion, that is the knowledge of Tawhid. And knowledge which is the 
nourishment of the religion, that is admonition and remembrance. And knowledge which is the 
(medicinal)treatment of the religion and that is fiqh (knowledge of rulings with their proofs). And knowledge which is the 
disease of the religion, and that is (the) reports about what occurred between the Salaf (the Companions). And a knowledge which is the 
destruction of the religion and that is 
kalaam.
 Al-Siyar of al-Dhahabi (17/482).