This is a branch of philosophical sciences whose origins lay on the distinction theorized by Socrates and the Sophists and clarified in Plato, who generally divides science into πρακτική (referring to πρᾶξις, action), and γνωστική (referring to γνῶσις, knowledge), and more fully in Aristotle, who adds the poetic (ποιητική, referring to ποίησις, productive action) to the theoretical (ϑεωρητική) and practical sciences. The term “practical,” that post-Aristotelians substituted with “ethical,” can be found again in medieval and scholastic terminology.
In the Kantian system, which hinges on the dyad of theoretical reason and practical reason, the distinction between practice and ethics or morals becomes clearer, with the former concerning, in general, the world of action and the latter determining, within this world, the sphere of morally valid activity. This distinction, present again in post-Kantian philosophy, was nullified by the actualistic idealism of G. Gentile, who conceptualized theory itself as a praxis and denied the possibility of an autonomous practical philosophy. From the second half of the 20th century, the distinction was reintroduced and re-proposed by the main German schools of thought, on the basis of a renewed critical reflection on the themes of action and political rationality.