لَا يَعْتَرِفُونَ بِمَعْلُومٍ لِيَثْبُتَ بِهِ مَجْهُولٌ
They acknowledge no known premise by which an unknown matter can be established.
Argument requires at least some shared premises or agreed standards for evaluating them. If one side refuses every basic observation, every report and every principle of inference, no proposed proof can bind that side on its own terms; its very starting points will be denied.
The difficulty is especially clear in the most radical form of the “I do not know” position. This is not a refutation of logic. It identifies a practical limit of debate when one participant refuses any common criterion for settling what follows from what.