Foundationalism and Presuppositionalism

So what is foundationalism? Why can’t one be a foundationalist and a presuppositionalist? That is what I will clarify here. The problem is that one cannot believe both systems. Foundationalism is an epistemological theory that makes claims about what it means to be justified in your beliefs. Presuppositionalism is semi-theological system that combines Reformed thought with epistemology. Since presuppositionalism denies that there is neutral ground between a believer and non-believer, it contradicts foundationalism when a few sensible facts are added.

One of the arguments for foundationalism is the regress argument. Make any statement such as “I am typing right now”. Then ask for the justification for that statement. Either the statement is justified by a second statement, it lacks justification or it justifies itself. If the statement is justified by a second statement, then we can ask about the justification of that second statement. If the statement lacks justification, then there is no reason to believe it. If these were the only two options, then either no statement would ever be justified (an infinite regress of statements lacking justification), or it is possible to justify in a circle. Since justification in a circle doesn’t work, then only option left is that some statements justify themselves. This is foundationalism.

Presuppositionalism does not allow for statements that justify themselves. Instead, reasoning in a circle is accepted. The circle may be quite large, but it is still a circle. The circle itself is presupposed – as a starting point or assumption. Since everyone is assumed to do this, there is nothing wrong with Christians doing it. Since the central beliefs of Christians and non-Christians will be different, their entire reasoning systems will be different as well. In a manner of speaking, they will share no knowledge in common.

Since foundationalists do not allow for the possibility of reasoning in a circle and presuppositionalists do, their systems are incompatible. Nor is this the only difference. Foundationalism allows that such beliefs as “I see a computer” are self-justifying. Since any two people in the same situation would share these beliefs, some of their knowledge would also be identical. Since every non-believer is in the same sorts of situations as believers (seeing physical objects) they will share knowledge with the believer. Therefore Christian foundationalists affirm that believers and non-believers share common ground in both belief and knowledge.