Presuppositionalism is an alternative approach to apologetics. It engages in a more indirect form of argument involving an attempt to demonstrate that, unless we presuppose the God of traditional Christianity, we cannot legitimately claim to know any of the things we ordinarily take ourselves to know. The presuppositions associated with any non-Christian worldview will lead to incoherence. Are the presuppositionalists right?
Here’s an instance of modus ponens (argument I):
- If Patrick harmed Daniel for fun, then Patrick is blameworthy.
- Patrick harmed Daniel for fun.
- Therefore, Patrick is blameworthy.
Presuppositionalists say atheists who want to make argument I wind up contradicting a presupposition of atheism: if naturalistic materialism is true, then no one is ever blameworthy for anything. So atheists affirm something (Patrick’s blameworthiness) while being committed to denying it, which is a kind of contradiction.
The claim, then, is that “You, atheist, can’t make sense of blameworthiness [also: objective morality, knowledge of the external world, logical laws] because it doesn’t make sense without a grounding supposition that God exists.” But why should we agree that if naturalistic materialism is true, then these judgments go out the window?1
Usually, instead of answering this question, presuppositionalists demand that atheists justify their belief in morality, knowledge of an external world and so on. I’m unsure what to think about this demand. Judgments about who has the burden of proof in a dispute are tricky, but it seems like a fair enough request and fairly easily met. I’ll discuss two responses. One deals with Patrick’s blameworthiness; the other deals with our knowledge of an external world.
A. Utilitarianism. Here is a perfectly valid argument (II):
- If utilitarianism is true, then Patrick is blameworthy for harming Daniel for fun.
- Utilitarianism is true.
- Therefore, Patrick is blameworthy.
From this (perfectly valid) subsidiary argument (III):
- If utilitarianism is true, then anyone who violates the principle of utility is blameworthy.
- Patrick harming Daniel for fun violates the principle of utility.
- Therefore, if utilitarianism is true, then Patrick is blameworthy for harming Daniel for fun.
What if the answer is that these are brute or basic truths? I’m not saying that utilitarians offer no arguments for utilitarianism (they do). But they don’t need them to defend themselves from presuppositionalists. Because, watch:
“Utilitarianism is a poor candidate for a brute or basic truth for the following reasons….”
This complaint switches goal posts. It’s not relevant whether presuppositionalists think that someone else’s foundational commitments are false, wacky or whatever. Whatever reasons presuppositionalists provide here, none of them will show that utilitarians have contradicted themselves or their worldview. Because, however crappy they think utilitarianism may be as a foundation for moral judgments, what is the contradiction supposed to be?
“Utilitarianism contradicts the way the world is -- the way God created it.”
Wrong goal post again. This is just a wordier way of saying that utilitarianism is false. Maybe utilitarianism really is false, but why should anyone think it implies a contradiction? Remember: presuppositionalists need atheistic arguments to imply a contradiction. If the objection is simply that utilitarian arguments rely on propositions that Christians reject, then presuppositionalism doesn’t do what its advocates claim.
B. G.E. Moore famously made the following argument for our knowledge of the external world:
- Here is one hand [waves].
- Here is another [waves].
- There are at least two external objects in the world.
- Therefore, an external world exists.
Well, presuppositionalists demand from atheists a justification for their belief that there are objects in an external world. Here it is: [wave, wave].
“But how do you know the first two premises?”
David Lewis said Moore’s argument suggests things called Moorean facts. These are propositions that we have more reason to believe than any reason there could be to the contrary, or one that we have more reason to believe than any more foundational propositions that would purport to validate it. Here are two pretty good candidates for Moorean facts:
- We have more reason to believe in the existence of hands than there is to believe any skeptical hypothesis concerning the external world -- that we might be dreaming, that we might be deceived by an evil demon, that we might be in the Matrix, etc.
- We have more reason to believe that harming others for fun is wrong than there is to believe any theory about what properly grounds moral judgments.
But presuppositionalists think Christianity is different because they think attempts to justify propositions without Christian presuppositions will end in contradiction. That just seems false. Presuppositionalists are objecting to the ways atheists attempt to justify their beliefs.
That’s a fine thing to do. It doesn’t deliver objective certainty about Christianity, but maybe attempting to uncover objectively certain propositions is a fool’s errand. Descartes notwithstanding, there are probably better ways to spend one’s time. As my colleague danced last week, we know lots of things by way of methods that don’t guarantee their truth.
1 Some arguments in this neighborhood are just bad, like Ivan’s in Dostoevsky’s The Brothers Karamazov that if God doesn’t exist then anything is permissible. Some are plausible if understood in a weaker way, like the idea that a certain understanding of morality fits more comfortably within a theistic worldview than a naturalistic materialist one and so the existence of God is the best explanation for the existence of objective moral facts.