This first transcription is taken from Clark's lecture entitled Questions and Answers. In it, Clark is a part of a panel comprised of theologians of all shapes and sizes, most of whom express admiration for Clark. It appears that each person on the panel had already given some sort of lecture and that the audience was allowed to ask the panel questions, most of which (in this clip, at least) were directed to or answered by Clark. There was a lively discussion on the image of God and a few questions pertaining to situational ethics, but Clark's most striking quote, in my opinion, was the following, especially given that my professor used a paper by Quine to attack "foundationalism" in my most recent philosophy class:
//Every system of philosophy – whether it’s Platonism or Aristotelianism in antiquity or logical positivism in this century – every system of philosophy must have a first principle. Since it is first it cannot have been deduced from anything prior. In this sense, logical positivism or Aristotelianism is just as fideistic as I am. It means that a person accepts certain axioms from which he deduces conclusions. I accept the truth of the Scripture as my axiom and deduce conclusions from that, and you can call that fideism, which some people think is a nasty term. It certainly means you have faith. The logical positivists place their faith in sensation. You cannot – and I wish to make this clear – you cannot guarantee the accuracy of observation by observation. If you wish to demonstrate the reliability of observation you’d have to have something prior to observation, but there is never anything prior to your first principle.//
A few reflections. I doubt that my professor would be very happy with this quote by Clark. He is a pragmatist rather than a logical positivist, but the positions are similar. He would say, I imagine, that to assert that all philosophical systems must have a first principle is inaccurate. And I imagine this is true, insofar as not all philosophical systems claim to have a first principle. While it should be remembered pragmatists such as my professor define knowledge and truth peculiarly, I think what Clark should have said - and it's easy for me to say this, since I have had time to think whereas Clark had to give an answer on the spot - was that all philosophical systems ought to have a first principle. I think Clark is more correct in Thales to Dewey (pg. 88):
//The demonstration of a proposition, such as any any theorem in geometry, is completed only when it is referred to the axioms. If the axioms in turn required demonstration, the demonstration of the proposition with which we began would remain incomplete, at least until the axioms could be demonstrated. But if the axioms rest on prior principles, and if these too must be demonstrated - on the assumption that every proposition requires demonstration - the proof of our original theorem would never be finished. This means that it would be impossible to demonstrate anything, for all demonstration depends on indemonstrable first principles. Every type of philosophy must make some original assumptions.//
I, like Clark, don't see any other way in which the infinite regression argument can be avoided.
More interesting than this technicality, however, is that Clark admits one's axiom(s) upon which he purports to construct his philosophical system is taken by faith. This perhaps distinguishes Clark from classical foundationalism - Clark does not appear to assert, as did the Rationalists, that first principles or axioms can themselves be indubitably self-evident.
John Robbins wrote that "Knowledge is true opinion with an account of its truth." Does an axiom have an "account of its truth"? Well, axioms can be reduced to absurdity by showing they lead to skepticism or internal inconsistency, but axioms cannot be demonstrated and, as such, apparently cannot be "known," at least not according to the above definition. I don't know whether or not Clark would agree with that. Perhaps epistemological self-attestation is relevant.
In any case, the above observations incline me to believe that Clark's position is a sort of synthesis between foundationalism and coherentism. Clark subscribed to a coherence rather than a correspondence theory of truth; that is, he believed propositions within a philosophical system ought to be internally consistent (cf. Clark and His Critics pgs. 142, 149). However, he believed the system must be grounded.
This may be too speculative, which is why it is stated somewhat tentatively, but for what it's worth, it makes sense to me. Scripturalism is rational because its basis yields epistemological consistency. Scripturalists utilize apagogic arguments rather than transcendental arguments, so a Scripturalists claims with regards to its axioms should be accordingly tempered (cf. here). One cannot prove an axiom, but it does not follow that one cannot be rational for believing an axiom.