Although Sproul respected Cornelius Van Til (his former teacher), he rejected the idea that Christians should begin by presupposing Scripture without prior rational justification. Presuppositionalism, he feared, led to a form of fideism where the unbeliever’s “autonomous reason” is simply denounced rather than engaged.

Sproul’s counter: The unbeliever already operates on the same laws of logic and moral intuitions as the Christian. The apologist can therefore appeal to common ground—not in terms of a neutral epistemology, but in terms of shared rational principles that are themselves dependent on the God of Scripture. Thus, classical arguments are not “neutral” but rather demonstrate that atheism is rationally self-defeating.

Sproul appeals to Romans 1:19–20 (God’s invisible attributes are clearly seen in creation) and Acts 17:22–31 (Paul’s use of Greek poets and natural reason at the Areopagus). These passages, he argues, mandate a rational apologetic that engages the unbeliever on common ground.


Important Note: As of this writing, Ligonier Ministries (founded by R.C. Sproul) and Reformation Trust do not offer a free, public domain PDF of Classical Apologetics. The book is still under copyright protection.

However, legitimate PDF versions are available for purchase through: