This paper consists in three case studies of modern French philosophers who drew their inspiration from Plato : Emile Chartier, known under his nom de plume Alain, famous as a teacher in the twenties of the last century, and two of his pupils, Simone Petrement and Simone Weil. Great admirer of Plato, Alain taught the survival of his main thoughts through all the philosophical tradition and their agreement with the rationalistic mood of 19th‑20th century philosophy. This implied that these thoughts (...) were stripped of the allegorical or mythological way in which Plato often expresses them. In particular, Plato’s allegory of the cave, one of his core images, turned out in Alain’s interpretation to be a metaphoric description of the difficult ascent of the mind up to scientific or at least rational knowledge. Consequently in this interpretation it was no longer question of any transcendency of the idea of the Good.Petrement and Weil remained faithful to their teacher and therefore to Platonic inspiration. Nevertheless, both of them, although in different ways, have reacted against this exhaustion of transcendence and come into conflict with modern interpretation of Plato. Petrement, even before specialising in the history of Gnosticism, worked out a dualistic system in which truth is absolutely transcendent because, as universal, it is unattainable for any particular mind inasmuch it is a subject’s mind. Truth, therefore, is unattainable throughout this life. On Weil’s part, the interest in Plato took place after a period of left wing militancy, following her discovery of Christianity and some personal experiences of mysticism. Platonism was for her a means of combining her new faith with a properly philosophical, i.e. rationalistic, way of thinking. Of course in this view transcendency was crucial to the idea of Good as much as to that of God. Whether this transcendency is more a matter of faith than of reason is at least uncertain. (shrink)