a valid rational proof. If reason is not a valid proof, it cannot be followed under any circumstances, let alone given precedence. Thus, giving reason precedence over transmitted revelation undermines reason itself, since its necessary implications and the conclusion it establishes would no longer hold. If giving it precedence over transmitted revelation undermines it, and undermining it prevents it from serving as evidence, while undermining its evidentiary force undermines its opposition to revelation, then giving it precedence when the two conflict invalidates that very opposition. It therefore cannot be given precedence over transmitted revelation, which is what was to be demonstrated.

[Giving Transmitted Revelation Precedence Does Not Entail Its Inherent Invalidity]

Giving transmitted revelation precedence over reason, however, does not entail that revelation is inherently invalid. This may be clarified as follows:

When reason opposes what reason itself has established as true, this indicates a weakening of its evidentiary force, which entails its invalidity. As for transmitted revelation, neither the invalidity of its evidentiary force nor any internal conflict within it has been established, even if its validity has not been established.

When two proofs conflict, one of which we know to be invalid while we do not know the other to be invalid, giving precedence to the one whose invalidity has not been established is closer to what is correct than giving precedence to the one known to be invalid. This is like a witness known to tell both truth and lies, and another witness whose reliability is unknown but who is not known to have lied. It is impermissible to give precedence to the statement of a sinful witness known to lie over that of a witness whose reliability is unknown but who is not known to have lied. How much more so when the witness himself has testified that he lied in some of his testimony?

If reason affirms the truthfulness of transmitted revelation in everything it reports, then says, “It has reported something contrary to the truth,” reason has testified both that transmitted revelation must be accepted and that it need not be accepted. It has testified that the proofs furnished by revelation are true and that whatever revelation reports is true; yet it has also testified that what revelation reports is not true. It is therefore like someone who testifies that a man is truthful and does not lie, then testifies that he has lied. This undermines both his testimony as a whole and his attestation to that man’s integrity. Neither his first testimony nor his second must therefore be accepted, and reason cannot serve to oppose transmitted revelation under any circumstances.