First:

If the innate disposition can contain two self-evident judgments, one accepted and the other rejected, this would undermine the foundations of all knowledge. No self-evident judgment could then be trusted.

Second:

If this possibility is admitted, the distinction between the two kinds must be drawn either through self-evident propositions or through propositions established by reasoning and based on self-evident truths. Both alternatives are invalid. For if we allow that some self-evident propositions may be false, we cannot know whether the self-evident proposition used to distinguish the true from the false among the original propositions provides a valid distinction until we know that it belongs to the true category. This, however, can be known only through another self-evident proposition that clarifies and distinguishes between them. That proposition, in turn, cannot be known to belong among true self-evident propositions except through yet another. This leads either to an invalid infinite regress or to a self-evident proposition whose truth is uncertain and which therefore provides no distinction. No means would then remain by which truth could be distinguished from falsehood, thus undermining the very possibility of distinguishing between them.

Moreover, conclusions reached through reasoning depend on self-evident truths. If self-evident propositions can be uncertain, containing both truth and falsehood, then conclusions based on them are even more liable to the same uncertainty. No knowledge would then remain by which truth and falsehood could be discerned. This encompasses every form of sophistry.

Even supposing sophistry to be valid, we would have no rational arguments by which anything could be established, let alone arguments that could contradict the truths of revelation.