Amartya Sen, economist and philosopher, is an intellectual who proposes to think the standard living of people from perspectives not focused in production and distributions of possessions and services as most important. This claim, the author propose the capabilities approach as a mechanist of social analysis, which from substantive freedom category, allows to determine standard living of comunities from human life diversity. The capabilities approach lead Sen to develop a democratic perspective towards public ratio, from it is proposed to think the citizenship as an agency, as a capability in order that individuals have a real impact in the world. Keywords: substantial freedom, capabilities approach, public ratio, democracy, agency, citizenship.