There is a line of argumentation that can really get a believer stuck on a position without being able to interpret any information to the contrary. This is presuppositional apologetics.
“Any argument presupposes a rational universe, of which only God can be the basis, any argument against this automatically fails. It’s like using your voice to argue sound does not exist. The very act of speaking confirms sound, the very act of reasoning confirms God.”
At its core it is a begging the question fallacy. If (1) god exists, and (2) god is the only reason for a rational universe, then the very use of reason is confirming god. But if either (1) or (2) are incorrect1, then we should be looking for other reasons.
By the Same Logic
The fun thing about fallacies is that, if we assume their logic is correct for just a little while, then we can use the same fallacy to show contradicting conclusions with equal validity. For example, the math-hypothesis: math and logic exist, objectively2, abstractly, uncaused, unchanging, eternal, but lacking any causal powers; it does however have patterns, those have internal causality. Maybe the universe is one of those patterns, such would be clockwork-like and thus a rational universe.
Now we can play the same game:
“Any argument presupposes a rational universe, of which only math and logic can be the basis, any argument against this automatically fails. It’s like using your voice to argue sound does not exist. The very act of speaking confirms sound, the very act of reasoning confirms math and logic.”
In response to any argument the other side makes, just reiterate they are confirming math and logic. And that by doing so they are borrowing from your worldview. If they ask why, restate the hypothesis that the universe is a mathematical pattern. Restate that their worldview is incomplete and inconsistent without this. That anything they try to show using logic, is necessarily within the domain of logic, thus smaller than logic.
Of course, doing so is entirely fallacious and very annoying. This all holds a great irony, the presuppositional apologetic is claiming that bad reasoning confirms God.
More Correct Presuppositions
- the ability to observe;
- to recognize patterns in the observations;
- to predict using those patterns;
- to recognize and remember patterns that predict observations well;
- eventually, to recognizing what causes the the patterns.
This is how babies begin to learn before they can use reason. This is how we come to common sense understandings. This is how science works, with a strong emphasis on predictions and testing. Even these assumptions themselves are a pattern, one that predicts following this method is a good way to gain knowledge, a prediction that matches observations quite well.
And no god appears in that description, to believe one exist, it should be justified by what we observe4. But instead we found and described a mechanistic universe filled with causes and effects, we call those the laws of physics. And we have no objective observations that these can be broken. We did find out that within these laws, learning is possible, and that is how we are here, observing the universe.
Both (1) and (2) are claims. Neither have been demonstrated to be true. Especially if god can act and make choices, then (2) is a very shaky proposition. ↩
To show math objectively exist, think about the number π, it is expressed in human symbols; human base 10; human choice of circumference divided by diameter and not radius. But it reflects an underlying, unit-less, constant, that can be found and confirmed independently. Aliens would find it too. ↩
Most philosophical axiomatic systems don’t actually articulate their axioms, but start with axioms like reality exists, math and logic work, and reasoning works. I like to focus instead on the method that generates knowledge. ↩
Believers often think they have extracted a pattern from observations. Usually experiences of when trusting god worked out, or feelings of guidance, or healing. But this is only step (1), (2) extracted with hindsight, and fails at step (3) and (4). ↩