The World Health Organization's (WHO) definition of health in their constitution is: "Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.” We, the Health and Systems Thinking Special Integration Group SIG, employ the Chinese five elements systems theory to categorize health systems into physical health (Earth), mental health (Wood), emotional health (Fire), behavioural health (Metal), and spiritual health (Water). This categorization would provide a systemic view for health systems and individual health, and could establish a platform to incorporate different Ancient-Modern, East-West health theories and practices. The book, “Systems Thinking for Health Systems Strengthening” ISBN 978 92 4 156389 5, published by WHO and alliance, shows that health and systems thinking is coming into the mainstream. Hence we adopt the concept of Unity in Diversity as our goal, to develop the health and systems thinking theories as part of General Systems Theory, to align with the ultimate purpose of ISSS.