Background Prison creates philosophical needs due to the exceptionality of the situation. This study explores how philosophy can meet these needs by focusing on three aspects: critical thinking, personal relationships and the government of passions. It builds on similar interventions in several countries and is proposed as a research that bypasses some limitations of previous projects in prisons.Method Following the participation of 81 inmates in 22 philosophical sessions over six months, the results of both interventions were analyzed using mixed methods, (...) as well as a pretest posttest design with a control group. Specifically, Webster’s Self Assessed Wisdom Scale, a questionnaire and an interview with four participants were used. These methods were triangulated in order to obtain data from the various methodologies and to improve the validity and reliability of the results.Results It was demonstrated that the experimental group showed significant progress in relation to the categories “openness”, “humor” and “emotion regulation”. Participants also showed a progression in categories related to the project’s goals. These results allow for a description of the categories that explain in what sense philosophy can act in the context of imprisonment.Conclusions This study demonstrates, on the one hand, how philosophy workshops involve outcomes linked to cognitive, affective and relational aspects. Furthermore, it provides evidence to confirm previous studies and interventions that are more modest in their results and use less rigorous scientific methodologies. (shrink)