Here is a conversation that Jimmy Stephens had about TACT:
What is your response to the idea that we must go through every worldview individually for TAG to work again? I don’t remember your last response
1.) That claim (because it is a claim) hinges on the concrete worldview of the claimant. It is therefore justified only insofar as the worldview. If we falsify the worldview, we falsify the claim. Methodologically, the only way to defend the claim that Christian alternatives are possible is to demonstrate an actual Christian alternative from which to make that observation.
2.) That claim confuses what a worldview is. The idea that multiple interpretations of reality, knowledge, ethics, etc., can be logically consistent is itself the doctrine of a pluralistic epistemology. So the claim confuses sub-interpretations of the worldview pluralism with a worldview. Of course, pluralism (of this variety) suffers many critiques.
3.) The claim neglects the idea that all non-Christian worldviews share an ultimate commitment to autonomy. Further, autonomy has only so many categorical variants with regard to metaphysics, epistemology, and axiology. Contra the claim, all we need to “go through” is a list that exhaustively classifies all worldviews. This is why Van Til talks about various dialectics, which Bahnsen went on to clarify.
4.) Transcendental argumentation is intrinsically aimed at unbelief. That is – and this is controversial – what makes a transcendental argument transcendental is that it shows how what is doubted preconditions the doubt, putting the doubter in a self-refuting situation.
I would argue that TACT need not propose some all-encompassing syllogism. It’s intent is at one and the same time more modest and more radical. More modest because it satisfies the goal to deal with one instance of unbelief at a time. More radical because the higher goal is to answer persons, not beliefs.
TACT is only useful insofar as it serves an apologetic purpose. It serves an apologetic purpose only insofar as it serves evangelism. It serves evangelism by confronting people in their unbelief.