Firstly...

Firstly, what is the basic feature that distinguishes all the various versions of materialism from theological realism, making them two conflicting schools? The answer is that the basic distinguishing feature of materialism is its denial that there is anything beyond the scope and realm of experimental science.

Both the theologian and the materialist accept the findings and formulations of science, but they differ over the issue that there is an immaterial realm of existence beyond the realm of experiment and sensible phenomena. The materialist considers natural causation revealed by experiments as the sole ground of all existence, including mind and consciousness. The theological realist, on the contrary, regards the knowing subject and its knowledge as being of an immaterial nature.

Further, theological realism asserts that the developments and movements studied by science are, in the ultimate analysis, attributable to a cause transcending nature and the material world. The materialist denies this and claims that no immaterial or transcendent causes are revealed in the field of experiment; nature is dynamic, autonomous, self-sufficient and self-contained. It is clear that there is no dispute between theology and materialism with regard to scientific truths.

The theologian admits all scientific truths; he just admits other truths and asserts the existence of a primary, non-sensible and immaterial cause of nature's movements and phenomena. Secondly, if the conflict between theology and materialism is that of affirmation and negation, which of the two schools is responsible for giving evidence in favour of its position?

The theologian must offer reasons for his affirmation and the materialist for his negation, for absolute denial like absolute affirmation requires proof. The materialist, by his absolute denial, in fact asserts that he has examined the entire realm of being and not found any immaterial cause in it. Now a second question arises : What kind of evidence that can be? The answer is that the evidence for the affirmation or for the denial must be based on reason, not on sense experience.

This is contrary to the materialist view, which considers sense experience as its evidence and claims that the propositions of metaphysics and theology cannot in general be verified by sense experience and that an analysis of experience and nature does not reveal the existence of immaterial things.