  In the Pancosmia Patrizi is intent upon replacing the four Aristotelian elements with his own alternatives – space, light, heat and humidity. Space (spatium) is viewed as preferable to the Aristotelian conception of “place”, construed as the inner surface of the body surrounding any object. Patrizi elevates the notion of space to make it the first principle of the corporeal world. Space is construed as prior to all bodies, even light, and constitutes two distinct realms.  Mundane space is finite in extent and contains the physical cosmos. It is surrounded in turn by an infinite external space empty of all bodies. The universe consists of three separate worlds: the “Empyrean”, an infinite space filled with light; the “Aetheric”, which contains all the stars and other heavenly bodies down to the Moon; and the “Elementary”, which embraces the sublunar realm.  Patrizi holds that the stars and planets move freely through the aether, doing away with the fixed celestial spheres which had dominated cosmology from antiquity and had even been accepted by Copernicus. 