  Quine can afford to vacillate because, in his view, nothing very much turns on the issue. In particular, he never holds that underdetermination, in any version, would threaten realism; at no time does he suggest that it casts doubt on the truth of our theory. That is not what is in question between the sectarian and the ecumenical positions; all that is in question is whether the alternative theory should also be counted as true. Nor is this surprising. The terms in which underdetermination is stated, such as observation categoricals, are part of our theory, as would be the demonstration that another theory was empirically equivalent. The point here is the naturalism which we have emphasized throughout. Nothing in our epistemology pronounces on the status of theory from an independent standpoint; to the contrary: it presupposes the truth of our theory. This central idea is not cast in doubt by underdetermination. (See Severo 2008; for criticism, see Moore 2015 and for a rejoinder to Moore see Kemp 2016.)