In 1971 John Rawls wrote his famous A Theory of Justice in which he presented what is known as ‘The Original Position.’ The OP is a hypothetical state of affairs in which an individual operates from behind a ‘Veil of Ignorance’ in order to establish principles of justice for society apart from considerations of ethnicity, class, gender, and the like. This thought experiment stems from the radical autonomy present in Immanuel Kant’s work.
Enough about Rawls. Cornelius Van Til was a Christian apologist who likewise drew from Kant’s work, taking the transcendental method developed by Kant (and many others before him) and more broadly applying it to the entire Christian worldview. Van Til proposed the Christian worldview as the only worldview capable of rendering human experience intelligible.
Now, sharper non-Christians, and even some Christians who ultimately oppose Van Til’s method, point out the possibility of some worldview X which might render human experience intelligible. The problem with that move is the need to simultaneously establish some platform with which to posit said possibility. Let’s refer to this hypothetical platform from which we might posit a hypothetical worldview X as the OP.
The OP in this instance is very loosely analogous to the Original OP above, or to put it another way, the OOP, which is rather confusing…I leave it to those more familiar with Rawls to decide how close OP and OOP (I did it again) are to one another, and even if objections to OOP are likewise analogous to OP, given that I am at all right about the possible (there’s that word again) similarities between OOP and OP anyway.
In any event, the purpose of the OP is to avoid hypothesizing from a Christian or (specific) non-Christian worldview. But the epistemology of modality for the Christian is worldview specific, even ethically obligatory at points, whereas the non-Christian functions, or attempts to function, within her own epistemology of modality. Strangely though, when speaking of the supposed necessity of the Christian worldview in virtue of transcendental argumentation, both Christian and non-Christian often attempt to think about philosophical objections posed by the possibility of X from something like an OP.
A non-Christian cannot posit that anyone (even a Californian), might propose a worldview that has not yet been refuted by the presuppositional apologist. They can’t do that when their own worldview is demonstrably insufficient for rendering human experience intelligible. Nobody actually operates in accord with OP, nor should we, which says a great deal about our epistemology of modality. Frankly, assuming OP against one’s own particular non-Christian worldview in order to claim the possibility of some worldview X whereby the necessity of the Christian worldview for intelligible experience is undermined is not terribly persuasive, to say the least. To say more, it’s not a move that’s even available to the non-Christian. And it’s certainly not available to the Christian.
The concept of possibility itself does not function in virtue of OP, no epistemology of modality ‘exists’ in a ‘void.’ Possibility is tied to respective worldviews. Yes, so is truth, so is transcendental argumentation, and so on and so forth. I see no difficulty here. Epistemological (not logical) circularity is a necessary feature of a rational worldview. So I’m proposing a radical commitment to Christian presuppositions in Christian apologetics, and the use of radical retortion against any view which is opposed to the Christian worldview. But that’s nothing new, either in my proposing it, or in your reading about it, if you understand the fact of it having been proposed already in the works of Van Til.
The concept of possibility is itself worldview specific, not neutral. A non-Christian with ‘no place to stand’ isn’t within her epistemological rights in telling others where others might stand; that’s an unintelligible epistemology of modality.