This thesis studies Miguel de Unamuno's Del sentimiento trágico de la vida within the context of his novel San Manuel Bueno, mártir. I aim to provide a synthesis of varying perspectives of San Manuel Bueno, mártir while suggesting that the protagonist don Manuel is both a social and a spiritual subject within his society. The complexity of his character implies the problematic nature of applying the philosophy of the tragic sense of life into the socio-political context of the novel. I also incorporate José Ortega y Gasset's España invertebrada to explain the spiritual sloth of the society in the novel. This thesis is in Spanish.