Presuppostional Apologists attempts to demonstrate the dependence of all worldviews on presuppostions and point out the inadequacy of all except the Christian set of presuppostions. Proponents include later Augustine, Orr, Van Til, Gordon Clark, Francis Schaeffer and others.

In my opinion, the presuppositional approach to apologetics is efficacious for defending the Christian faith. Unlike the Classical and Evidential approaches, which seem to challenge the non-Christian from external positions, Presuppositionalists challenge the non-Christian from an internal position; presuppositions.

I can appreciate Schaffers one-on-one presuppositional strategy. Rather than attempt to force the Christian world view on an unbeliever (which would probably be an exercise in futility), this approach is person-centered and seeks to examine with the non-Christian the presuppositions underlying his system of beliefs. In so doing, it pushes them to their own extreme; the logical conclusion of their pre-suppositions. It is at this point that the non-Christian makes the relatively astounding discovery that he is not living consistently with the world view he himself holds.

It has been said that there are many non-Christian scientists who do not truly believe in the theory of evolution but accept it simply because it is the only alternative to creation. This suggests to me that there may also be many non-Christians who are non-Christian by choice. They are aware of and may even acknowledge their inconsistent living. They prefer this unreality or reality as they know it over and against accepting Christianity. Therefore, Schaffers approach may not always be workable, especially if Christianity is not explained and shown to be the best explanation for reality as it is and for practical living. Of course this is one of the inherent difficulties of all apologetic approaches.

Another concern one may have with this approach is that it may put hearers on the defensive. When pushed to the logical conclusion that he/she is not living consistently with his/her own world view, the non-believer may become resistant feeling his/her back is to the wall. So even though Schaffer urges one-on-one encounters, I am not sure that this approach might not better be applied in churches or groups where the individual ego is less likely to be provoked.

Overall, I think this approach can be useful and is certainly worthy of consideration. However, I am of the mindset that no Christian apologist can show that every non-Christian system of thought is inconsistent or that a totally consistent non-Christian world view does not exist.