I put forward the argument in Presuppositionalist Nonsense Part I and Part II that the law of non-contradiction is not necessarily universal, thus refuting the position of presuppers who claim, without proof, that the laws of logic are abstract, universal and invariant. This also invalidates their claim that God's nature is universal, since the laws of logic are apparently a reflection of his nature.
So, the presuppositionalist worldview is defunct.
But why leave it at that?
The non-universality of the law of non-contradiction is only one reason why presuppositionalism is wrong. By exploring the claims of its followers it quickly becomes obvious that they are riddled with self-refuting statements. For instance, the presupper claims that their foremost presupposition is that God exists and is the source of truth, knowledge, logic, etc...But where does the presupper get this claim from? How can they account for it?
In order to make such a claim, the presupper must first presuppose the existence of the very same things that God is supposedly the source of - truth, knowledge and logic
- The presupper presupposes truth as they already accept their claim to be true.
- The presupper presupposes knowledge as the very act of making the claim is itself a knowledge claim.
- The presupper presupposes logic as they use logic to arrive at their claim.
So the original presuppositions being made are actually that truth, knowledge and logic exist. Therefore it isn't necessary to claim that a magical being accounts for these concepts, since they are already being presupposed in order to make such a claim. Essentially, if a presupper is honest they would be forced to admit that they are in the same position as any other person with regards the origin of concepts such as truth, knowledge and logic - they don't know. I would posit that there is no exact origin of these things since they are axiomatic. They are just abstract concepts that describe reality.
Another self-refuting position that the presupper holds is the claim that an omniscient omnipotent being can reveal things to a human in such a way that they know them to be certain (Sye repeats this ad nauseum - see answer no 9 and 18 here). Now this may or may not be possible, but if it is possible then one would also have to concede that it would be equally as possible for an omniscient omnipotent being to reveal things to a human in such a way that they simply think they know them to be certain, when in fact they are not (Sye eventually admitted that this was a possibility here and later here).
The fact that the revealed truth could simply be a trick cancels out the claims of certainty in the presupper's original statement. How could they actually be 100% certain of the truth if the devious omniscient omnipotent being is just fooling them to think they have been revealed the truth. Since in both scenarios they would be absolutely convinced that they know the truth with complete certainty, there would be no way for them to distinguish between the two.
Now the presupper will try to discredit this by saying that they do not simply think they know something for certain - oh no - they actually know it for certain. If you suggest that many people claim the same thing (e.g. Mormons, Scientologists, etc), they will respond by indicating that in your examples the people simply believe they know something, but they do not actually know anything...
We are supposed to believe that presuppers know the truth simply because they say so, yet subscribers to all other religions only believe they know the truth....
There is one way and one way only to know 100% that you are correct. That is to have absolute knowledge (omniscience). Since no human has omniscience any claims to certainty are bogus, because it would be impossible to verify these claims unless the recipient was also omniscient and thus could know for certain that the revelation was not simply a trick. Certainty is impossible without omniscience so revelation is moot.
Is there another way to verify that the revelations are in fact certain?
Well, one place to start would be to find out how God is supposedly revealing these things for certain. Thus I posed the question to Sye over at SMRT:
Could you do us all a favour and ask God to reveal to you how he does this?
To which Sye answered:
I could, but I won't.
He later went on to admit that even if God explained to him how he reveals things for certain, he wouldn't understand the explanation. Well, this simply means that Sye is taking it on faith that things are being revealed for certain. He does not KNOW anything, he BELIEVES it. His claims to certainty are refuted... again.
So the presupper's position is clearly based on faith, not certainty.
But the idiocy doesn't stop there folks. Here's another dishonest approach used by presuppers:
When you ask them a question which they know they cannot answer, they will do everything they can to deflect the attention back on you. They will revert to their 'how can you know anything' or 'how do you account for the logic you are using to ask that' response. The point they are trying to make is that one needs to be able to account for logic in order to use it so they need not answer your question until you account for the logic you will use to evaluate their answers.
Talk about a cowardly response!
Of course, it is completely irrelevant for the discussion as one does not need to know how one knows things in order to know things. If this was a requirement, how would you know it? Also one does not need to account for logic in order to use it just as one does not need to know exactly how a car works in order to drive one.
Finally, I read another interesting article which refutes an aspect of presuppositionalism over at Incinerating Presuppositionalism, which is an excellent resource. Here Dawson Bethrick argues that a core principle of presuppositionalism - the revealed knowledge of the uniformity of nature - is inconsistent with the idea of an omniscient omnipotent being capable of performing miracles.
Because Christians affirm belief in an omnipotent supernatural being which can do what Van Til claims here, they cannot bank on any fact with any certainty, for unless they are themselves omniscient (which would make them “God,” and there can be only one “God”), they cannot know if or when their god might take any fact and “set it into new relation to created law.” The believer's god is supposed to have a will of its own, independent of the believer's own will. So how can the believer know if or when his god is going to cause another miracle to take place, especially if he relies on "divine revelation" (i.e., information which his god chooses to distribute to the believer) for all his knowledge?
Think about it.
If someone accepts that God can turn water into wine, then he/she can never be sure that the water they are about to drink will remain water, as it could possibly become wine at the whim of God. Similarly, any seemingly uniform aspect of nature could be altered as part of a miracle, meaning that a presupper has no basis for assuming the uniformity of nature.
So another certainty claim bites the dust...
But why do presuppers continue to spout their nonsense in the face of such transparent inconsistencies?
My take on it is that Sye and other presuppers are run-of-the-mill Christians but with one significant difference - they know that simply 'having faith' is a silly justification for their beliefs. So they desperately try to justify or account for their worldview in terms of logic. I think that deep deep down they know their argument is flawed but, crucially, they still believe it anyway, probably because they are willing to ignore a few anomalies and inconsistencies for the 'greater good'.
That's presuppositionalism folks. It is fundamentalist faith, pure and simple. Mix in a heavy helping of tirelessly regurgitated loaded questions and a pinch of non-answers, simmer at a circular heat and serve with a side of smugness.