The article presents a multidimensional analysis of inequality, in a global perspective, distinguishing vital, existential, and material resources inequality. These dimensions are interrelated and interacting, but irreducible to each other, and have had different historical trajectories, within and between nations. Over the last half-century, the contrast between advances of existential equalization, on one hand, and persistent, even increasing, vital inequality of life expectancy and health is striking. Inequalities are produced by specific mechanisms, of which distanciation, exclusion, hierarchization, and exploitation are the most important. They have each their corresponding mechanism of equality, of rapprochement or approximation, of inclusion, of organizational flattening or de-hierarchization, and of redistribution, rehabilitation, and recompensation. The mechanisms and their results are illustrated empirically in a systematic global overview.