 Tilting the conceptual landscape via prior commitments is both an equal opportunity epistemic necessity and a potential pitfall here. Insisting on pushing an explanatory factor back a level is often an indication of a strong prior commitment of some sort. Disagreement over deeper philosophical or other principles will frequently generate divergence over when something has or has not been explained away. One side, committed to the principle, will accept a level change as embodying a deeper insight into the relevant phenomenon. The other, rejecting the principle, will see an ad hoc retreat to defend an α which has in fact been explained away. 