This article presents a diachronic and systematic analysis of Martha Nussbaum´s philosophical work, for the purpose of explaining her political liberalism, which articulates the reflections about justice and cultivating humanity in a cosmopolitan perspective, as keys for understanding and building democracy in the present world. Nussbaum´s proposal connects technical and practical dimensions of politics, in order to protect individual freedom, guarantee material opportunities for self realization and promote social cohesion through solidarity, respect and mutual recognition.