He exhorts budding apologists to use the argument that without God, intelligibility, morality, etc are not possible. Notice that there’s still no argument that God exists, still no evidence, still no reason to think that such an entity is possible, plausible, likely or necessary in the universe that we inhabit. Yet Bahnsen presupposes that God exists AND is the source of “rationality, communication, meaning, science, morality, man’s redemption and renewal”. We look at his claim, and immediately see that the first five topics can be explained in natural terms by eighth-graders, and the last two are vague enough to need a better definition before the counter-apologist even bothers. “Redemption and renewal” sound like code-words to the emotionally needy, so I can see why he’d throw those in for their benefit.
The apologist explains how rationality, communication, meaning, science, morality, man’s redemption and renewal are quite understandable, meaningful, coherent, or intelligible within the Biblical worldview-within “the picture” of thinking God’s thoughts after Him.
In the same paragraph, he continues:
We saw the exact phrase “preconditions for the intelligibility” in Pastor Stephen Feinstein’s attempt to debate Russell Glasser, so Bahnsen’s words appear to be the direct ancestor that inspired Feinstein to think he had a knock-down argument against the “atheist world view”.
The apologist then engages in an internal critique of the unbeliever’s worldview to show that it is (1) arbitrary, and/or (2) inconsistent with itself, and/or (3) lacking the preconditions for the intelligibility of knowledge (language, logic, science, morality, redemption, etc.). Since that is the case, the unbeliever cannot “know” the things which he urges against Christianity-indeed, could not know anything at all and loses all claim to rationality.
Still, there is nothing - absolutely nothing - in the Bible that remotely makes any assertion that could be spun into support for such a bizarre set of claims as Bahnsen is instructing the apologist to make. It’s almost as if he’s setting them up for ridicule of the highest order. We get a peek into how he might have arrived at this:
Here, Bahnsen exposes his reliance on theologian and presuppositional apologist Cornelius Van Til's work - specifically, as his student and critic John Frame relayed, that the “sovereignty of God” was an “epistemological, as well as a religious and metaphysical principle.” That God is required for intelligibility.
Take anything about which the unbeliever is committed or concerned-anything which seems uncontroversial and agreed upon by the unbeliever and believer alike-and from that point display that it would be unintelligible or meaningless or incoherent if the unbeliever’s worldview, instead of the believer’s, were true. ... And the philosophical issues about which Van Til wrote we should broach to prove the unbeliever’s epistemology and discredit the unbeliever were extensive and varied.
An undiscriminating apologist - Feinstein, for example - might take Bahnsen’s (Van Til’s) exact words and repeat them verbatim without giving any serious thought about how a real argument is supposed to support a claim. That appears to be what happens a lot, when all you have to do is claim “goddidit”.
More in a while.