The essay discusses the relationship between philosophy of law and legal science in the writings of Arnaldo Volpicelli. According to his thought, the search for an ontological dimension of phi-losophy passes through a critique of Benedetto Croce’s and Giorgio Del Vecchio’s scholarships. The definition of gnoseological function of science, on the other hand, takes place through a comparison with Vittorio Emanuele Orlando’s and Santi Romano’s works.