Basic worldviews are never demonstrated; they are chosen. William James and Bertrand Russell may believe in a pluralistic universe, but they can offer no demonstration of this, the most fundamental of their intellectual beliefs. The mechanist believes that all natural phenomena can be reduced to mathematical, quantitative equations, but he never gives a mathematical demonstration of his belief. So it is with every world-view; the first principle cannot be proved – precisely because it is first. It is the first principle that provides the basis for demonstrating subordinate propositions. Now if such be the case, the thoughtful person is forced to make a voluntary choice. As a matter of fact, the thoughtless person as well is forced to choose, though the necessity to make a choice and the particular choice made may not be so obvious. It is obvious, however, that a thoughtful person, one who wishes to understand, one who wants to think and live consistently, must choose one or another first principle.A Christian Philosophy of Education, 19
Still it remains true that no demonstration of God is possible; our belief is a voluntary choice; but if one must choose without a strict proof, none the less it is possible to have sane reasons of some sort to justify the choice. Certainly there are sane reasons for rejecting some choices. One most important fact is the principle of consistency. In the case of skepticism inconsistency lies immediately on the surface. Explicit atheism requires only a little analysis before self- contradiction is discovered. Some statements of naturalism more successfully disguise their flaws. But all these choices are alike in that it is not sane, it is not logical, to choose an illogical principle.
Consistency extends further than a first principle narrowly considered, so that it can be shown to be self-contradictory in itself; it extends into the system deduced from the first principle or principles. The basic axiom or axioms must make possible a harmony or system in all our thoughts, words, and actions. Should someone say (misquoting by the omission of an adjective) that consistency is the mark of small minds, that he does not like systems, that he will act on one principle at one time and another at another, that he does not choose to be consistent, there would be no use arguing with him, for he repudiates the rules, the necessary rules of argumentation. Such a person cannot argue against theism, for he cannot argue at all.A Christian Philosophy of Education, 41-42
When now the theist speaks of theism as a practical postulate, he is not indulging in any “as-if” philosophy. He means that God exists and that one should conduct his daily life by that belief. It is called a postulate because it is an indemonstrable first principle and not a theorem derived from more ultimate premises.A Christian Philosophy of Education, 42-43
It is better to say that the truth of the Bible is the basic axiom of Christian theism, for it is there alone that one learns what God is. It is there alone that one learns what man is. And what children are. And what college students are. And what education should be. There is still more but this chapter does not aim to give an account of the entire system. In conformity with tradition, the argument has centered on the question of God’s existence. As an axiom or first premise it is incapable of proof or demonstration. Right from the start, at the very beginning, we say, “I believe in God the Father Almighty.”A Christian Philosophy of Education, 43
The Christian system starts with God – not just any sort of God, but with a very definite God, the God of the Bible.A Christian Philosophy of Education, 105
But what about these assumptions or axioms? Can they be proved? It would seem that they cannot, for they are the starting points of an argument, and if the argument starts with them, there is no preceding argumentation. Accordingly, after the humanist or theist has worked out a consistent system by arranging all his propositions as theorems in a series of valid demonstrations, how is either of them to persuade the other to accept his unproved axioms? And the question is all the more perplexing when it is suspected that the axioms were chosen for the express purpose of deducing precisely these conclusions.A Christian View of Men and Things, 26