 Where does the above analysis of existential dependence lead us? The case of Socrates’s life demonstrates that  (EDR)  permits the possibility of mutual existential dependenceR between non-identical things. But this implication does not seem to be acceptable in every context and indeed symmetric dependence more generally is a controversial issue (see Barnes 2018 for discussion). Take, again, the relationship between Socrates and his life. According to (EDR), Socrates is quite as much existentially dependentR upon his life as his life is upon him. And yet there is a strong intuition that, in another and perhaps more important sense, Socrates’s life is the truly dependent object here, while Socrates is, in some sense, an independent existent. We might say that Socrates’s life exists only because Socrates does, whereas it would be putting the cart before the horse to say that Socrates exists because his life does. Now, it appears that the conjunction “because” must be asymmetrical, because it expresses an explanatory relationship and explanation is asymmetrical. Plausibly, two distinct states of affairs cannot explain each other. There may, quite conceivably, be self-explanatory states of affairs, so we should only want to urge that non-identical states of affairs cannot be mutually explanatory. Technically, this means that we should strictly describe explanation as an “antisymmetric” rather than as an asymmetric relation. The asymmetry of explanation is, of course, intimately related to the unacceptability of circular arguments. It is also closely linked to recent discussions regarding metaphysical grounding, to which we will return later, in  §5.