Presuppositional apologetics

Presuppositional apologetics is a form of Christian apologetics, primarily in the Calvinist tradition, that asserts that the acceptance of the proposition "God exists" and the truth of the Christian Bible is necessary in order for the world to be intelligible. Presuppositional apologetics usually begins with the rejection of Thomist apologetics, which attempt to establish logical proofs for the existence of god, accepting the rules of logic prior to accepting the existence of God. The Transcendental Argument for the existence of God (TAG) is often considered a claim of presuppositional apologetics, though it is also used (in a somewhat different form) in Thomist apologetics.

There are two historically distinct branches of presuppositional apologetics: Van Tillian presuppositionalism and Clarkian presuppositionalism, attributed to their namesakes, Cornelius Van Til and Gordon Clark.

Basic Forms and Principles

Van Tillian Presuppositionalism

Van Tillian presuppositionalists accept that the Bible is the sole arbiter of whether a proposition is true or false; as a result, all knowledge claims must be given Biblical justification. They cannot be known independently of the Bible.

While it grants that the laws of logic and causality are true, it does not accept that they are foundational. Rather, it asserts that those propositions are true if and only if the truth of the Bible has been granted. In this argument, the basic laws of logic must be supported by Biblical justification, otherwise they are false.

Skeptic: Is modus ponens the case?

VT Apologist: Of course modus ponens is the case. It is one of the most important rules of logic.

Skeptic: But isn't modus ponens, given its standing as a rule of logic, foundational?

VT Apologist: No. Only the Bible is foundational. Modus ponens can be used to check the coherence of other propositions with the truth of the Bible.

Van Tillian presuppositionalism also engages a distinction between proof and persuasion. There can be conclusive proofs of the existence of God, through logic, however Van Til recognizes that many of these proofs are not pragmatically persuasive. Van Til asserts that this is because the skeptic rejects the epistemological framework (Platonic epistemology) necessary for the acceptance of those proofs. Van Til, in particular, was active in advocating Platonic epistemology as the only epistemology that is Biblically defensible.

Directly, Plato's epistemology differs from Van Til's in one very important respect: Plato does not accept the Bible as the foundation of his epistemology. For Plato, the Forms are foundational, and there is no text which can communicate the forms to individuals. For Van Til, the Forms are secondary to the belief in God and the truth of the Bible, and belief in the Forms is justified by the Bible.

Van Til, himself, popularized a version of TAG, based on the role of the reciprocal relationships of the ontological trinity. There is some confusion about the exact structure of the argument, as it varied throughout Van Til's own writing. However, the traditional formulation is that the reciprocal relationships of the Trinity, being higher order relationships that exist outside of a relationship to the physical world, are the fundamental basis for logical relationships, and so reason is contingent on the existence of the Trinity. This is a particularly odd series of arguments, and is one of the bases for Van Til's version of presuppositionalism, because it allows for the Biblical account of God to be foundational for the laws of logic, instead of allowing the laws of logic to be primitive. This version of the argument is problematic, because the relationship between entities is a synthetic statement (pet Kant) while the laws of logic are analytic statements.

Clarkian Presuppositionalism

Clark treated the truth of the Bible as though it were the axiom of a logical system. Clark asserts that the worldview that results from the acceptance of the axiom can be tested for consistency and comprehensiveness. Clark is committed to demonstrating that there are no discrepancies or contradictions which can be produced by accepting the Bible as true, and embraces the possibility of using formal logic as a method for testing the propositions in order to ensure this. Because the Bible is foundational to a logical system, if it produces contradictions, then it must be rejected.

The idea that the Bible can be found to have contradictions draws some criticism from the Van Tillian branch, because they feel that the Bible should not be weighed against logical axioms. If an axiom is found to, hypothetically, demonstrate a contradiction within the Bible, then the problem is the axiom. Because Clark accepts that the laws of logic have bearing on falsifying the Bible, Van Tillian's often argue that this is not a genuine sort of presuppositionalism, and that it puts the laws of logic on the same foundational basis as the Bible.

Concerns about Platonic Epistemology

Reformed Epistemology

There are many schools of epistemology that are explicitly religious which have a concern with the acceptance of Platonic Epistemology. This is particularly true of the reformed epistemology movement. The concern is that the Platonic theory seems to be treating the existence of God as the existence of a category, rather than as the existence of an object (or fact). If we accept that God is a particular "form" in the sense of Platonic epistemology, then there is some concern about whether or not God is actually an instantiation.

For the reformed epistemologists, God must be actual, and it will not do for God to be a general claim which has a number of instantiations. The reformed epistemologists have a concern with the Platonic epistemology that it requires them to create a singular category for God, of which God would be the only member. The concern, here, is that many of the presuppositionalists want God to be, or be indistinguishable from, that category.

Secular Concerns

Most secular epistemologists now reject Platonic epistemology in favor of Kantian or Quine-ian epistemology. Even Cartesian epistemology (despite some of the concerns in cognitive science and some of the infinite regression concerns) is often considered more sound than Platonic epistemology.

The major issue is that Platonic epistemology maintains that categories are objective. This is not something that most epistemologists are willing to commit themselves too, as it makes some serious presuppositions about philosophy of mind which are not accepted in the field. Most epistemologists maintain that, to some degree or another, the categories that exist in logical systems are a cognitive necessity, but not objective. Whether there are any objective category is an open question among philosophers, but most reject the idea that all epistemological categories are objective.

Perceptual categories, like color, are now understood to be incredibly fluid across cultures. This presents a problem, as the property of red-ness is not an objective property of the objective, but a property of the object as it is represented in the brain/mind. The property of the object has to be described differently, because color is too fluid to be used as an objective descriptor.

Critiques

Critique from Un-Falsifiability

One critique of presuppositional apologetics is that it is committed to the claim "God exists" being true; however, because it asserts that the existence of God is necessary for any belief to be intelligible, it is not possible for this claim to be found to be false. The exchange looks something like this:

Skeptic: What would have to be the case for you to reject the belief that God exist?

Apologist: There isn't anything, because my ability to know anything is conditioned on God existing in the first place. If there were conditions such that God didn't exist, then I wouldn't be able to comprehend God existing, or not existing, or any belief.

The move that the apologist makes is a reversion to the belief being primitive.

The concern is greater, though, when it comes to the belief about the truth of the Bible. If it is the case that the Bible makes claims which are empirically verifiable, and those claims are not verified upon investigation, then there are some serious concerns regarding whether the empirical methods are to be dispensed with. This is similar to the issue of whether the Bible produces logical contradictions; in Clarkian presuppositionalism, this is regarded as being a genuine problem.

Critique from Modal Logic

One critique of presuppositional apologetics is that it makes a non-tautological existential claim (i.e. 'God exist') primitive. It is generally accepted, in logic, that only universal claims (all x are y) and tautological claims (some p is p) can be primitive.

In modal logic, existential claims about logical possibilities (like 'God exists') are generally believed to be true in at least one possible world and false in at least one other possible world. Because they are generally accepted as being false in some possible world, they are not considered necessary truths. Only necessary truths can be primitive.

Critique from the Canon

The critique from Canon expresses a problem when it comes to accepting the Bible, as the text has shifted over the years, and the method for assessing whether or not the texts that exist in the current form are considered an adequate representation of either the traditions of the early Church or a reasonable representation of the events that they purport to recount. One of the major issues in this case is the concern over the omission of additional sources from the Biblical Canon. Because presuppositionalists are, generally, protestants, there are some concerns about whether the authority of the early Church extended to the inclusion or exclusion of texts from the Bible. While this is generally an argument amongst Christians, who tend to have misgivings about papal authority, there can be a sharp point made by skeptics.

This is colloquially referred to as the "Which Bible?" argument. Because presuppositionalists believe acceptance of the Bible is primitive, there is some concern about whether or not they can have a non-Biblical justification for accepting the version of the Bible that they do.

This argument is supposed to put the presuppositionalist in a dilemma: Any reference to the Bible in justifying the use of a particular version of the Bible is question begging and any admission that there is a non-Biblical reason for choosing a particular version of the Bible requires the presuppositionalist to give up the Bible as foundational, as such a justification constitutes an alternate foundation.

One common move out of this is to defer to divine revelation, which requires a move to another series of arguments, including whether or not the reliability of the subjects experience is already predicated on the existence of a God who would reveal himself through divine revelation, in order to establish another possible instance of question begging.

List of Presuppositional Theologians

Cornelius Van Til

Gordon Clark

Greg Bahnsen

John Frame

Rousas John Rushdoony

Francis Schaeffer

Douglas Wilson

Sye Ten Bruggencate