The Monday meeting of the Defenders of Denethor is now in session. I commented over there, but I’m putting this here because Stephen’s got a serious discussion going on, and this gets less serious the more I think about it.
Where I think we both ended up is, Denethor is doing the right thing according to his reason. His proposed course of action is entirely defensible, all his priorities are well established, he’s acting within his authority, and if anything went wrong his CYA package was in order. Unfortunately, he’s operating outside the theater of reason alone. The circumstances require faith in Something much greater than the works of Men, which Denethor doesn’t have, or hasn’t found use for in government.
Here in our world, any christian (and large numbers from other religions) will tell you we have Scripture to tell us about that Something. Nothing of the sort exists in Gondor. I suppose the Steward could go ask Elrond, which is kind of what Boromir is doing at the Council. Or he could ask Galadriel and Celeborn, since they were around for even more of the backstory. Or Círdan would have an interesting perspective. But these people all have their own interests, their own motives. He’d never be sure they were telling him everything. If you really want Denethor to take supernatural powers into his calculations, you’d have to give him something in writing.
What 
if Denethor got hold of a copy of the Letters? Would that have the same theological impact as the Epistles of St. Paul have in ours? After all, Middle Earth has an omniscient creator (he’d say “subcreator”) who knows and sees all, and has a Plan for the world.
The book would contain the creator’s secret thought, his intentions that didn’t make it into the obvious plot. It contradicts itself in some places, and is frustratingly silent when it gets to some things you really need to know. Some parts would make no sense at all to a character from LotR. It has all the trappings of the foundational text of a religion.
Somehow, though, I don’t see the Men of Gondor accepting it that way.
The Hapsburg Restorationist
Another very thought provoking post, would you mind if I took the role of friendly opposition? I disagree with several points of your posts, but in this comment I’d only like to suggest that the Gondorians do have a “scripture” that they might consult, the (sometime called) “Golden Book”. The tetralogy of the Ainulindalë, the Valaquenta, the Quenta Silmarillion, and the Akallabêth certainly serves many of the functions of a scripture, and together with the Atanatárion (i.e. the three “Narn”s ), the Annals and Book of the Kings, and possibly the Athrabeth Finrod ah Andreth, would have most probably formed the foundational education of a noble descended from the Númenórean “Faithful”, most certainly of a ruler. Of course this is just conjecture, but it is I think logical considering the extensive knowledge of these works that Aragorn has as Dúnedain Chieftain (though it would be proper to note the current form of them is that we have received from Bilbo’s translations).
Joe
This website’s policy is that all commenters have to disagree with the Idiosopher at least once. So bravo!
This is an area where I don’t know much. I think of The Silmarillion as Bilbo’s Translations from the Elvish, which means that Denethor couldn’t have read them. Is there anywhere that it says Gondor’s libraries had a copy of the Golden Book? I thought it was an Elvish thing. Or a Lost Road thing.
The Hapsburg Restorationist
Ah, here we come to the murky edges of canonicity where be dragons! and adventure for those who will take it. I have to admit that my conjecture is on somewhat shaky foundations when it comes to purely textual evidence. If one goes by Unfinished Tales (The Line of Elros: Kings of Númenor), then Elendil is the author of the original form of Akallabêth and it was indeed preserved in Gondor; “Of the deeds of Ar-Pharazôn, of his glory and his folly, more is told in the tale of the Downfall of Númenor -which Elendil wrote, and which was preserved in Gondor.” As for the rest, Denethor speaks of “records of the ancient days” but this could refer to any period before or even during the Third Age. It could be inferred that the Teleri when they visited the Númenóreans taught them the lore of the First Age and the time before, and through the Elendili it survived in Gondor (“Thence the Eldar came to the Edain and enriched them with knowledge”); the Annals of the Kings contains a kind of summary of the Silmarillion but it is hard to say if this predates the Thain’s Book (Pippin’s copy of the Red Book), which could have possibly been Gondor’s only record of the Elder Days. Then too, even if Gondor originally had the records or part of the records, they could have been destroyed, or preserved in some archaic Westron dialect which only Gandalf could read. In any of these cases, Denethor is off the hook.