The Traditionalist School, more ambiguously Traditionalism, is a philosophical/religious school that in its modern form was founded by René Guénon, but its principles are considered eternal, originating from the same source, and present in all authentic religious traditions. Various aspects the modern world and modernism are considered to increasingly deviate from this. See also Perennial philosophy.
While most members are not especially controversial politically, that is not the case for Evola, likely contributing to some not considering him to be a member. "Radical Traditionalism" is a term for Evola's ideology.