It is quite useless to debate a presuppositional apologist.
In presuppositional apologetic all worldview is wrong and only their "Christian" worldview is the right one. So presuppositional apologetic is fideism. That is also what traditional Christian apologists says about them.
As stated by the Christian-website CARM, "Presuppositional apologetics differs from Classical apologetics "in that presuppositional apologetics rejects the validity of traditional proofs for the existence of God. A pure presuppositionalist tackles the worldview of a person and seeks to change the very foundation of how a person perceives facts."
Paul Copan (professor and Pledger Family Chair of philosophy and ethics at Palm Beach Atlantic University) explain...
It engages in question-begging—-assuming what one wants to prove. It begins with the assumption that God exists, and then concludes that God exists. Such reasoning would get you an “F” in any logic class worthy of the name!
Presuppostionalists seem inconsistent about natural theology.
For me, the fatal flaw of presuppositional apologetics is that it doesn't offer an adequate account of the relevant phenomena. The presuppositional apologist offer no explanation and if that's the case, then their view cannot be taken seriously.
