Schaeffer was no systematician, not involved in creating an apologetical methodology - for better or worse. (See William Edgar's excellent article "Two Christian Warriors: Cornelius Van Til and Francis A. Schaeffer Compared," Westminster Theological Journal 57.1 (1995): 57-80. Edgar, now at Wstminster, studied with both Schaeffer and Van Til.)

Schaeffer has some "presuppositional" influences, but all in all is very eclectic. Sometimes he even argues like a Thomist with some kind of nature/grace-dualism: he says that unbelievers only have "one half of the orange" and the apologict must give them the other. So, the are right "as far as it goes"... Also, Schaeffer usually let human reason (natural reason) stand unchallenged and unchecked for far too long. The Bible came in very late... Only after the preparatory work of reason has been done, the evangelist can appeal to the unbeliever to repudiate his autonomy and accept the dogmatic truth of Scripture. I don' t think that works!

__________________
Sebastian Heck
PCA & yet to be founded Reformierte Kirche Deutschland
Ph.D. student at Theological Universiteit Apeldoorn/Netherlands
Church Planting in Germany
Reformation2Germany