  To Bernard’s skeptical challenges Autrecourt replies that sense experience is reliable. This theme is not further developed in the letters to Bernard, however. For discussion of this topic we must turn to the Exigit ordo. In one section of this treatise, which is reminiscent of Aristotle’s Metaphysics IV, 5, Autrecourt addresses one of the central issues of metaphysics, namely the relation between appearance and reality. He addresses Protagoras’ view that whatever is apparent is true: An omne illud quod apparet sit? (Does everything that appears exist?).