Adopting classical/evidentialist arguments

An issue in apologetic methodology is whether it's consistent for a presuppositionalist to adopt arguments from classical or evidential apologetics. That depends in part on whether we define presuppositionalism as an apologetic methodology that only deploys transcendental arguments. I think that's an unduly narrow. One role of presuppositionalism is to take advantage of what had been a neglected type of argument for theism: transcendental arguments. But that doesn't mean other types of arguments should be excluded.

One issue is whether criteria are worldview dependent or worldview independent. Classical and evidential apologists accuse presuppositionalists of vicious circularity. Classical and evidential apologists try to isolate and identify a set of general criteria that can be used to evaluate any competing worldview. 

If, however, there's only one God and one reality, then ultimately our criteria derive from that reality. Criteria must match reality. At that level, criteria are bound to a particular worldview–the true worldview.

A Christian apologist can't just play the rules of the atheist (or Buddhist). Those may be arbitrarily restrictive and slanted. Sometimes a Christian must challenge the criteria of the atheist. Or explain that his criteria require a more robust worldview that's at odds with naturalism and physicalism. It isn't necessarily possible for Christians and atheists to arrive at a common set of rules. 

This also goes to the question of how much is riding on God's existence. In addition to contingent facts, presuppositionalists think logic, mathematical truths, moral realism, and possible worlds are grounded in God's existence. If so, our criteria can't be independent of God's existence because they derive from God's existence. (According to natural law theory, there's a sense in which moral realism is a contingent fact, based on God's design for human creatures.)

However, that's viciously circular only if there's no way to demonstrate the claim. If, though, it's possible to formulate arguments which demonstrate that logic, morality, modality, and math require God's existence, then it's not viciously circular. By process of elimination we rule out naturalistic explanations. But that's philosophically demanding, painstaking process. A work in progress. 

It's consistent for a presuppositionalist to adopt arguments from classical and evidential apologetics so long as we acknowledge that those are worldview dependent.