 Eternalism too, prima facie, would seem to have trouble accounting for the asymmetries built into possibilism, while also apparently bearing the burden of an implausible denial of passage. But the first topic to which we shall turn is an argument, prominent in twentieth century philosophy of time, that passage or becoming is a self-contradictory idea. If the argument is correct, then neither presentism nor possibilism can be correct metaphysical views of time and being.