Learning from Lasaulx: The Origins of Brentano’s Four Phases Theory

Throughout his career, Franz Brentano argued that philosophy underwent regular, and somewhat necessary, cycles of rise and fall that could be analyzed according to four relatively discrete phases. This theory of the ‘four phases of philosophy’ was a decisive factor motivating him to believe in his own role as the herald of a new phase of scientific philosophy at the turn of the nineteenth to the twentieth century. This essay explores how and whether Brentano’s four phases theory might have been inspired, in part, by the work of his teacher Ernst von Lasaulx, a classicist at the University of Munich. Brentano attended Lasaulx’s lectures in 1856–57, and he spoke positively about the experience throughout his life. Though limited by what the historical sources contain, this essay suggests that there is warrant to think that Lasaulx encouraged Brentano’s concern for the possibility of recurrent patterns in history, and reinforced his desire to revive philosophy in his own day.