This is not a promotion of Gordon H. Clark as a true Christian. However, I think there are some helpful things that can be culled from his capacious intellect. Most of these excerpts have to do with indemonstrable axioms or presuppositions (all underlining mine).
“…one must come to realize that a system of truth must begin somewhere. For that matter, a system of error must also begin somewhere. If it did not begin, it could not continue. This is to say that every system of philosophy [or system of thought, if your prefer–CD] must have a first indemonstrable axiom…the Christian should, though many do not, choose as his axioms the propositions of Scripture, and from these axioms he may develop an orderly system.
Upon hearing this, many friends and enemies alike will object that this begs the question. It does not. The question is, Where shall we start? Some say sensation; I say revelation. One does not beg the question by answering the very first question.
Of course, it is permissible for the opposition to argue that his opponent’s axioms result in self-contradiction. And of course that is precisely what the seventeenth century rationalists, the nineteenth century higher critics, and the twentieth century existentialists have done. But the Hittites destroyed the higher critics, and the law of contradiction destroys the existentialists. If anyone wish to pursue this in detail, there are various volumes within easy access” (Clark).
“…However, Feigl makes his point incontestable. His choice of induction, as a choice, shows that any system must have a starting point. If a system has no starting point, it cannot start, nicht? But a starting point cannot have been deduced or based on something prior to the start, for nothing is prior to the start, n’est-ce pas? Every system, therefore, every attempted system, must have an original, undeduced axiom. Our dear friend Aristotle noted this, for he argued that if all propositions had to be deduced, they would regress to infinity, with the result that nothing could be deduced.
Since even Communism cannot prevent one from choosing whatever principle seems best to him, the Christian will choose the God of truth, or, if one prefer, the truth of God. He then proceeds by deduction, that is, by the law of contradiction, for the law of contradiction is embedded in the first word of Genesis. Bereshith, in the beginning, does not mean half-way through. That is to say, Scripture throughout assumes the law of contradiction, viz., a truth cannot be false” (Clark).
“Let it be noted, in case Beegle or anyone else should miss the point, that evangelicals, defined historically as those who hold to sola scriptura and sola fide, do not assert the truth of 2 Kings on the basis of Assyrian inscriptions; nor do they assert the truth of Satan and Michael, or David and Daniel, on the basis of archaeological or historical investigations. Evangelicals assert the inerrancy of the whole Bible on the ground of its own claims. The Biblical teaching is axiomatic. It is not deduced from previous external axioms. But this does not make evangelicals ‘conveniently blind.’ They are very happy to face the ‘facts’ of Assyrian inscriptions and other archaeological debris. But what they find in them is neither proof nor disproof of Biblical infallibility. What they find in them is ad hominem arguments discomfiting to the liberals – no more, no less. Of course, evangelicals have a priori axioms. The liberals also depend on indemonstrable assertions. Every philosophic system must have a starting point, or else it does not start. But sometimes the liberals talk as if they had discovered ‘facts’ without starting from historiographical assumptions” (Clark).