This essay offers a critical reconstruction of Noberto Bobbio's concept of liberty. The historical and analytical review of his work leads to the identification of three descriptive uses of the concept of liberty: negative or liberal liberty, democratic liberty or autonomy, and positive liberty, of a socialist type. In the second part, the reaches and limitations of these three uses are commented on, highlighting the insufficiency of dichotomy between negative and positive liberty, the incompatibility of negative liberty with the legally and fundamentally reinforced idea of liberty consecrated in the Colombian Constitution and the foundation of social rights such as the realization of liberty, that in a State based on the rule and law can be based independently or as a means to be able to really exercise the liberties.