The objective of this work is to report an experience of participatory teaching developed by us, in a Brazilian public university, in the discipline of General Theory of Law. Often, the Science of Law seeks to rationalize and legitimize contingent political decisions, presenting them as the result of a natural development of the normative system. In our article, we defend that legal education must combat such positions, denouncing the mystifications promoted by jurists. The method of participatory teaching that we use seeks to stimulate students to identify social problems not yet solved by the legal order, and to propose legal responses to these topics. Initially, we make considerations about the sense of the General Theory of Law discipline. Next, we report on the teaching-learning experience that we implement, with special emphasis on the students' performance in the execution of the project. Finally, we reflect on the theoretical implications of the debated experience, from the students' reactions and from our personal observations.