3 Step Presupp Approach

  1. Identity the preconditions behind the feature of human experience that is being discussed. For example, in order for science to be possible: 1) nature must be uniform 2) reason must be reliable 3) the laws of logic must exist.
  2. Conduct an internal critique of the non-Christian worldview showing how it is unable to provide the presuppositions for those preconditions.
  3. Invite the unbeliever onto the Christian worldview and explain to them how it is able to provide the necessary presuppositions for those preconditions.


Materialist Thoughts

‘If the solar system was brought about by an accidental collision, then the appearance of organic life on this planet was also an accident, and the whole evolution of Man was an accident too. If so, then all our present thoughts are mere accidents—the accidental by-product of the movement of atoms. And this holds for the thoughts of the materialists and astronomers as well as for anyone else’s. But if their thoughts—i.e. of materialism and astronomy—are merely accidental by-products, why should we believe them to be true? I see no reason for believing that one accident should be able to give me a correct account of all the other accidents. It’s like expecting that the accidental shape taken by the splash when you upset a milkjug should give you a correct account of how the jug was made and why it was upset.’

C.S. Lewis (1898–1963), The Business of Heaven, Fount Paperbacks, U.K., p. 97, 1984.

Vindicating the Notion of Causality

“the argument that we only believe that ‘A’ causes ‘B’ because we always see ‘B’ following ‘A’, assumes the very causal principle whose objectivity it is denying! It does this because it establishes a causal connection between our observations and our belief in causality. But how can the causal principle be used to explain away causality? It involves an absurd contradiction. Secondly, it is not true that our belief in causality is only supported by habitual observation of external events. It is also rooted in our own internal mental experience. We are, for instance, immediately and intimately aware of the fact that our acts of will determine and control our subsequent behaviour. We know that our decision to go to Paris for a holiday results in our booking a flight to the French capital and our presence on the appropriate aircraft. We similarly perceive that there is a causal connection between our invention of a fictional character and our presentation of him to the outside world in our first novel. It is therefore extraordinarily perverse to claim that we cannot prove the reality of causality. Its objective presence in our experience is manifestly self-evident. Furthermore, the significant fact that we have direct and intimate knowledge of the causal principle in our own creative experience, offers the strongest possible support for the cosmological case for the existence of God.”

(Vander Elst, Is there No God?)

Naturalism is Self-Refuting

“Consider the standard naturalistic explanation for the origin of life, which is that all life evolved unguided through natural selection (and some other mechanisms like genetic drift) working on random genetic variation. All the diversity of life is explained in this way. The trait of natural selection favors are those that confer on the recipient a survival advantage. So ultimately the origin of our beliefs too must be explained in terms of survival.

Natural selection works because some mutations confer on the recipient a survival advantage, allowing such individuals to propagate more abundantly than their less well-adapted relatives. While other genetic variations may occur, if they do not affect survival positively or negatively, natural selection cannot work on them. For example, natural selection may provide for sharp horns on water buffalo, but it would not account for a trait such as blue eyes (assuming for argument that blue eyes grant the water buffalo no survival advantage).

Natural selection can also work on inheritable traits that regulate behavior. So the water buffalo fortunate enough to inherit a gene that disposes it to run away at the sight of lions will survive to reproduce beyond its unfortunate cousins who see lions as potential mates or furry friends.

Superficially it might seem that this explanation would allow for the production of systems that produce true beliefs, since true beliefs are likely to be conducive to survival. So philosopher Jerry Fodor says, “Darwinian selection guarantees that organisms either know the elements of logic or become posthumous.” But this inference from Darwinian selection to true beliefs is fallacious because natural selection works on behavior not beliefs. That is, some behavior bestows on an organism a “survival-enhancing propensity,” then natural selection can prefer it. What the water buffalo believes about the lion is irrelevant as long as his behavior enhances his survival. He might believe that when he sees a lion, it’s time to migrate quickly to another area in search for food. Or he might believe that the lion is his mommy but believe falsely that the way to get her to live him is for him to run away. Notice that such a false belief will still produce behavior that confers on the water buffalo a survival advantage. The point is that any number of beliefs, most of which are wildly false, is consistent with a survival-enhancing behavior. In fact, almost any belief could be tethered to a certain behavior. As long as the behavior is conducive to survival, it is susceptible to natural selection’s invisible hand. Given such a process for the production of belief, how likely is it that any one of our beliefs is true?

…So if this naturalistic account is true, there is a remarkably low probability that any of our beliefs is true. Most simply put, natural selection working on behavior vastly undermines true belief. Since the theory itself is commended for belief, it has a component that generates skepticism. And notice that this skepticism gets turned back upon the theory itself because among those of our beliefs would be naturalism combined with the Darwinian account. So if they were true, we would have little reason to trust that our belief in them was true. So the theory naturalistically construed is self-refuting.”

(Dembski, Unapologetic Apologetics)

Presuppositional Questioning: Problem of Evil

When an unbeliever challenges us “If God is all-powerful and loving, why is there evil and suffering in the world?” They have provided us with a lot rope to use to either hang them with and/or defend ourselves from their objection. They mention important concepts such as “God” , “all-powerful and loving” and “evil and suffering” which are packed with assumptions they are making. To handle this objection, we don’t want to answer immediately, rather we want them to clarify from what authority and source they are deriving these concepts from. Here is a way we can deal with this common challenge:

Make them aware of the obvious.

Clearly they are critiquing the Christian God, however, these questions are meant to make them verbally state the obvious. But why? This will provide a basis for the next question to ask them.

  • Which god are you talking about?
  • You mentioned God is all-powerful and loving, where did you derive these attributes from? In other words, which God are you referring to
  • Which god has an inconsistency with the evil and suffering in the world?
  • Are you talking about the Christian God?

Make them aware of what kind of critique they are performing.

When they talking about evil and suffering, they are appealing to some kind of standard derived from a source. They can firstly be performing an external critique, that is, they are appealing to their own standard of evil and suffering derived from their own experience of the world. Secondly, they can be performing an internal critique, that is, that are appealing to the Bible’s very own standard of evil and suffering, with the reality of evil and suffering found in the pages of Scripture. Unbelievers might not even be conscious of what kind of critique they are using, so these questions can help:

  • What standard of evil and suffering are you appealing to?
  • Are you deriving the reality of evil and suffering from the Bible or your own experience?


  1. External Critique: If they appeal to an external standard of evil and suffering, then you have a basis for performing an internal critique of their position by challenging their standard of good and evil, and reveal that they have  no basis on their worldview.
  2. Internal Critique: If they are appealing to the reality of evil and suffering as described in the Bible itself, then you only have basis for providing a negative apologetic. You can only provide an answer to the problem of evil found in the Scriptures.

Presuppositional Questioning: Evidence

Probably the most common challenge you will receive from an unbeliever is for you to simply provide them evidence for Christianity. However, as presuppositionalists we understand that what one accepts to be evidence and how evidence is interpreted is determined by his presuppositions. Furthermore, his presuppositions are governed by his ultimate presupposition or ultimate authority. Instead of naively providing them evidence to evaluate, we must make them conscious of their presuppositions and ultimate authority and how they influenced their criteria of evidence. We ultimately must challenge the unbeliever to justify his ultimate authority and demonstrate to them that it is either: 1) arbitrary or 2) circular. In both cases, we should demonstrate that their worldview fails to provide the preconditions for the intelligibility of human experience.

Here are some questions we can ask the unbeliever in return for their demand of evidence:

1. Make them aware of their criteria 

  • What do you accept/consider to be evidence?
  • How do you determine what is and isn’t evidence?
  • What is your criterion/standard of evidence?
  • What do you mean by evidence?

2. Make them aware of their presuppositions 

  • How did you arrive at/choose that standard for evidence?

3. Make them aware of the arbitrariness or circularity of their ultimate authority

  • How do you know that standard of evidence is the correct one/valid?


Whether a Fact is Truly a Fact

“Presuppositions determine whether a fact is truly a fact for someone’s chosen worldview. For example, a person holding anti-supernatural presuppositions will ignore, reinterpret, or even discard evidence that does not support his worldview in order to ensure  that his worldview is not invalidated. Throughout this process the claim is made by anti-supernaturalists that they are being neutral and objective, that they don’t hold presuppositions that influence the way they evaluate evidence. As one skeptic of scientific objectivity observes, “How good was the evolutionary evidence? Perhaps in addition to those 100 million facts that proved evolution, there were another 100 million facts they had chosen to ignore that proved something else.” Presuppositions determined the reality of facts.”

(DeMar, Thinking Straight in a Crooked World, 111)