The assertion of one who says:
If revealed and rational evidence conflict—or revelation and reason, or transmitted texts and reason, or the apparent meanings of transmitted texts and conclusive rational proofs, or any similar formulation—then one must either accept both, which is impossible because it entails accepting two contradictories; reject both; or give priority to revelation, which is impossible because reason is the foundation of transmitted texts. If we gave transmitted texts priority over reason, this would undermine reason, which is their foundation; and undermining the foundation of something undermines the thing itself. Giving transmitted texts priority would therefore undermine both transmitted texts and reason. Reason must consequently be given priority; the transmitted texts must then either be reinterpreted or their meaning left to Allah.
If, however, their opposition is that of contraries, they cannot both hold, but it is possible for neither to hold.
Al-Rāzī and his followers have made this argument a universal rule for determining what may be used as evidence from the books