I have been slowly studying the presuppositional approach for a few years, find merit in it, and generally think through issues the best I can in this way. However, one issue keeps nagging in my mind which I am wondering how to sort out. A problem with the classical/evidential approach is that it ultimately appeals to man's autonomous reasoning etc. (among other things). However, by reasonining with someone that they cannot reason without God, are you not appealing to their autonomous reasoning to understand their inability to account for reasoning without God. That is, still, at the base level there is an appeal for them to see the logic of the logic of presuppositionalism. Not sure if that makes sense, any suggestions?