 Although What Is in Parmenides has its nearest analogue in these divine principles, Parmenides himself never in the extant fragments calls What Is divine or otherwise suggests that it is a god. Instead, he develops an exhaustive conception of the attributes what must be has to possess, by systematically pursuing the fundamental idea that what must be both must be or exist, and must be what it is, not only temporally but also spatially. Whatever other attributes it might have that cannot be understood to belong to it in one of these ways do not enter into Parmenides’ conception of What Is. Thus it has none of the features of the religious tradition’s heavenly gods that persist as attributes of Xenophanes’ greatest god, despite resembling it in other respects. If Xenophanes can be seen as a founder of rational theology, then Parmenides’ distinction among the principal modes of being and his derivation of the attributes that must belong to what must be, simply as such, qualify him to be seen as the founder of metaphysics or ontology as a domain of inquiry distinct from theology.