 Grosseteste takes up Aristotle’s arguments for a beginningless world in his  Hexaæmeron and, in greater detail, in the closely related treatise On the Finitude of Movement and Time. In both works he holds that Aristotle was led to propose his erroneous arguments as a result of a failure to adequately grasp simple eternity.  Grosseteste is prepared to grant that Aristotle and other philosophers proved that God exists and is unchangeable and non-temporal and that they indeed had some grasp of simple eternity. Even so, their incomplete understanding of simple eternity meant that they did not really understand what they proved.  This lack of understanding was due to a disordering of their affectus or will, rather than of their aspectus or reason. This distinction between affectus and aspectus, which appears to derive from Augustine, is characteristic of Grosseteste’s thought (see Smith 2018). According to Grosseteste, genuine understanding requires that one’s will or desires be directed away from the sensible world to the unchanging eternal realm, but Aristotle and the other philosophers, being preoccupied with the sensible world, could not achieve true understanding.