Health inequity, main issue of contemporary debates on public health, is based on philosophical and historical concepts that date back to the idea of justice from classic Greece. The Aristotelian approach on distributive justice and its higher form, epiekeia or equity, has been reviewed, as well as how this evolves from the Middle Ages and modernity to the heart of the debate of a variety of thinkers such as liberal Rawls and Nobel laureate Amartya Sen. On this conceptual debate lies the World Health Organization version that links equity to health determinants and intends to make it operational through the equitable provision of health services.