Maharishi Ayurveda: Lecture by Dr. Jim Davis, D.O, Chapter 3 Ayurveda is the oldest system of medical knowledge and has been practiced for thousands of years in the Indian subcontinent as well as all of Asia. In this lecture, a trained medical practicioner in Western medicine explains the principles of Maharishi Ayurveda in simple understandable terms. Chapter Three discusses the main theory of Ayurveda, the differences between Vata, Pitta, and Kapha.