… there is an ongoing realism/antirealism debate in philosophy. However, this debate concerns mostly epistemological problems regarding the justification of more detailed realistic claims such as the status of unobservable entities, the truth of scientific theories, etc.
Well perhaps questions of completeness and realism are not what Mahner wants to address in his paper, or perhaps they are just inconvenient. In any case, Mahner is stuck with losing one or the other. As we have discussed before, such as here, here and here, those who mandate method necessarily lose a guarantee of either completeness or realism.
Bacon forfeited completeness and Descartes forfeited realism, but evolutionists will forfeit neither (which is possible only by introducing additional metaphysics which, of course, evolutionists do).
When mandating methodological or metaphysical naturalism, questions of completeness and realism immediately become important. But evolutionists want simply to mandate naturalism without reckoning with the implications. Mahner’s paper, unfortunately, does nothing to remedy this.