[Ideas, beliefs, and perceptions about health. History summary].

To get a closer approach to the concept of health, this paper reviews the ideas, beliefs, and perceptions about health that have been accepted by Eastern and Western cultures. Health conceptions by philosophers, physicians, and thinkers are presented, particularly as they relate to substances, forces, and elementary biological principles of the human body that determine human life and fate. Analysis of these conceptions makes it possible to recognize different definitions of health as a status of balance, harmony, and equity. On the contrary, disease has been defined with the antonyms of health words. The ecological theory of "resilience" may be useful to analyze the adaptive capacity of ecosystems and to suggest ideas for physiological research on processes leading the human body to a new status of balance with the external environment, and thus define the blurring boundaries between health and disease.