This dissertation analyzes how the Participatory Budgeting experience, such as the one that has taken place in Porto Alegre, Brazil since 1989, helps human beings develop the capabilities they will need to be the subjects in a transition to a participatory socialism that unifies human essence and existence. The frame for this analysis draws on Karl Marx's view of human nature and how capitalism blocks the human vocation of self and species development. Marx observed that capitalism subordinates workers in their workplaces. The division of labor and the subsequent specialization, when not occurring in a collectivist self-governing society, serve as the basis for the separation of the workers from their product. Various forms of alienation build on this separation, with the result in the end that these very products serve to support the subordination of the workers. The subordinate workers are denied the free exercise of their physical and especially their mental capabilities, the keys to human development and thus authentic human existence. Under capitalism human work is reduced to something nonhuman, something that for instance can often be replaced by machines. Instead of giving the pleasure of authentic self-expressing and self-developing work, crippled alienated work subjects workers to continuous displeasure. Participatory Budgeting is an experience of direct democracy inspired by the Paris Commune. It promotes the participation of people in local decisions. Notwithstanding that the participation is restricted to the government budget, its tremendous social importance comes from the process of educating people about how they can be active members in the social collective they are part of. This expanded engagement in social activity develops the participants themselves in two ways. First, it develops their awareness and understanding of the entire social environment they are presently part of, far beyond only budgetary matters. This understanding of their subordination and of the block that capitalism imposes on their human goal of self development then serves to motivate them to end their subordination, and to do with the system of capitalism that subordination is an essential part of. Second, this activity begins to develop the social and technical skills necessary for self-governance in a nonhierarchical society. Activity such as participatory budgeting thus can serve as the foundation for both the desire and ability to create a different future that is the negation of capitalism, democratic participatory socialism.