The right to the highest attainable standard of health should be the cornerstone of any consideration of health and human rights. The content of this fundamental human right is now sufficiently well understood to be applied in an operational, systematic, and sustained manner. At the heart of the right to the highest attainable standard of health lies an effective and integrated health system, encompassing medical care and the underlying determinants of health, which is responsive to national and local priorities and accessible to all. Yet in many countries, health systems are failing and collapsing, giving rise to an extremely grave human rights problem. This article outlines the general approach of the right to the highest attainable standard of health toward the strengthening of health systems. It identifies some of the key right-to-health features of a health system, such as transparency, participation, equity and equality, a comprehensive national health plan, a minimum "basket" of health-related services and facilities, disaggregated data, monitoring and accountability, and so on. This general approach has to be consistently and systematically applied across the "building blocks" that together constitute a functioning health system. By way of illustration, the article applies this approach to one of these "building blocks:" leadership, governance, and stewardship. There are numerous health movements and approaches, including health equity, primary health care, social determinants, and so on. All are very important. But it is misconceived to regard human rights as yet another approach with the same status as the others. Like ethics, the right to the highest attainable standard of health is not optional--and, like ethics, it recurs throughout all other approaches. The right to the highest attainable standard of health is the only perspective that is both underpinned by universally recognized moral values and reinforced by legal obligations.