Over the history of philosophy and religion numerous works of metaphysical speculation have been written. Many of these metaphysical models are mutually exclusive. This bewildering variety of metaphysics naturally induces a skepticism of all metaphysical systems. No particular metaphysics can be be proven empirically. Metaphysicians must recourse to either theophany or reasoning; in practice usually a combination of the two. Others cannot access the same theophany or may dispute their logic.
Materialism cannot escape this skepticism. Materialism (or physicalism) is the current prestige metaphysics in the modern world, but it has not earned this position on the basis of its veracity. Science as the study of physical or social phenomena, does not concern itself with non-physical phenomena. It is instrumentally materialist, regardless of the individual scientist’s metaphysical views. Although science uses materialism as a working assumption, it does not and cannot attempt to prove it, nor any other metaphysical model. The prestige materialism currently enjoys is a result of people mistaking this instrumentality for veracity.