 In his Livre du ciel et du monde and in other works (Questiones super De celo, Questiones de spera) Oresme brilliantly argues against any proof of the Aristotelian theory of a stationary Earth and a rotating sphere of the fixed stars. Although Oresme showed the possibility of a daily axial rotation of the Earth, he finished by affirming his belief in a stationary Earth (Clagett 1974, 225; Di Liscia/Shapiro 2020). Similarly, Oresme proves the possibility of a plurality of worlds, but ultimately keeps to the Aristotelian tenet of a single cosmos (Clagett 1974, 224–225; Harvey 2011).