 The question concerning the nature of God’s agency also has bearing on the nature of matter and form in the translunar world. Matter and form are attributed to worldly beings and to the celestial bodies only equivocally—otherwise celestial beings would suffer generation and corruption as beings in the sublunar world. The immaterial form of the celestial spheres guarantees their eternal movement, and by eternally moving them God is constituted as their efficient cause (Montada 2013: 179). The nature of translunar matter and form was also discussed by Averroes in his De substantia orbis, a work on which Del Medigo wrote a lengthy commentary where he discusses the equivocal meaning of matter and form. Del Medigo references De substantia orbis throughout his works, again exemplifying the unified nature of his works, having at its focal point the works and doctrines of Averroes (see Licata 2015: 94).