Presuppositional apologetics is the "school of apologetics developed by Cornelius Van Til. It rejects classical apologetics, and insists that fruitful
arguments establishing the truth of Christianity can only be made by identifying a person's presuppositions and having correct ones. 
"Due to the noetic effects of sin, presuppositionalists usually hold that there is not enough common ground between believers and unbelievers that would allow followers of the prior three methods to accomplish
their goals. The apologist must simply presuppose the truth of Christianity as the proper starting point in apologetics. Here the Christian revelation in the Scriptures is the framework through which all experience is interpreted and all truth is known.
Various evidences and arguments can be advanced for the truth of Christianity, but these at least implicitly presuppose premises that can be true only if Christianity is true. Presuppositionalist attempt, then, to argue transcendentally. That is, they
argue that all meaning and thought - indeed, every fact - logically presupposes the God of the Scriptures.
"John Frame represents presuppositionalism in this volume, and he puts the matter this way: [We] should present the biblical God, not merely as the conclusion to an argument, but as the one who makes argument possible (...). By demonstrating that unbelievers can not argue, think, or live without presupposing God, presuppositionalists try to show unbelievers that their own worldview is inadequate to explain their experience of the world and to get unbelievers to see
that Christianity alone can mkae sense of their experience."