According to Tattvarthasutra, 2nd century CE Jain text, yoga is the sum of all the activities of mind, speech and body. Umasvati calls yoga the cause of "asrava" or karmic influx as well as one of the essentials—samyak caritra—in the path to liberation. In his Niyamasara, Acarya Kundakunda, describes yoga bhakti—devotion to the path to liberation—as the highest form of devotion. Acarya Haribhadra and Acarya Hemacandra mention the five major vows of ascetics and 12 minor vows of laity under yoga. This has led certain Indologists like Prof. Robert J. Zydenbos to call Jainism, essentially, a system of yogic thinking that grew into a full-fledged religion. The five yamas or the constraints of the Yoga Sutras of Patanjali bear a resemblance to the five major vows of Jainism, indicating a history of strong cross-fertilization between these traditions.[note 16]
The meaning of health has evolved over time. In keeping with the biomedical perspective, early definitions of health focused on the theme of the body's ability to function; health was seen as a state of normal function that could be disrupted from time to time by disease. An example of such a definition of health is: "a state characterized by anatomic, physiologic, and psychological integrity; ability to perform personally valued family, work, and community roles; ability to deal with physical, biological, psychological, and social stress". Then in 1948, in a radical departure from previous definitions, the World Health Organization (WHO) proposed a definition that aimed higher: linking health to well-being, in terms of "physical, mental, and social well-being, and not merely the absence of disease and infirmity". Although this definition was welcomed by some as being innovative, it was also criticized as being vague, excessively broad and was not construed as measurable. For a long time, it was set aside as an impractical ideal and most discussions of health returned to the practicality of the biomedical model.