It is common use at the end of the century to make retrospectives in all domains: politics, sciences, military, arts... This has also been made in philosophy, and it tries to explain the world from fightings between one another, lists of great men names, the death of the field itself, rhapsodies of schools and philosophers, conceptual exhibitions of external problems (biographic, politic or colonial ones) and so on. In this paper, it is intended to give a criterium internal to the philosophy itself, in order to classify the philosophical thought all along the 20th century. This criterium has to be built as a philosophical idea in which are situated the methods, the ontologies and the ethics. It is here proposed that that Idea is the Boolean- Fregean Logic that renews the Aristotelian one and that leads to a great expectance but also to great refusals of its capacity to reorganise the problematics and argumentations of the philosophical tradition (problem of the universals, categories theory...).