The author highlights the relevance that the study of the legal past has for anyone who cultivates the Law. Given the different modalities that this presents, the curricula must choose to teach some of them, given the temporary impossibility of covering them all. In this dilemma, the teaching of positive, civil (as opposed to canonical) and public law is proposed. Within the latter, it suggests that preference be given to Constitutional Law given the repercussions it has on the experience and achievement of the common good.