If Denethor hadn't committed suicide

[Ibrîniðilpathânezel]

There is an aspect to Denethor's madness and Saruman's fall that I have often wondered about, something that Gandalf says to Pippin after they have started the ride to Minas Tirith:

"And how it draws one to itself! Have I not felt it? Even now my heart desires to test my will upon it, to see if I could not wrench it from [Sauron] and turn it where I would..."

Also of note, I think is Gandalf's slightly earlier remark concerning the palantir:

"But there is nothing that Sauron cannot turn to evil uses. Alas for Saruman! It was his downfall, as I now perceive. Perilous to us all are the devices of an art deeper than we possess ourselves. Yet he must bear the blame. Fool! to keep it secret, for his own profit."

Given that Gandalf felt that pull after a very brief time in the vicinity of a palantir, and the fact that Saruman -- whose art was almost certainly much deeper than Denethor's -- was drawn into his own downfall via the palantir of Orthanc, how strongly did the palantir of Minas Tirith begin to pull at Denethor's mind, once Sauron started using the Ithil stone? I often think that it was only a matter of time before Denethor was pulled into a similar fate, one custom-made for his particular weak spots, simply because he lived so close to a thing that (for all I know) might have been whispering in his thoughts, both awake and asleep. Before he started using the palantir, Denethor appears to have been a good leader, even though his bearing could be rather arrogant at times. His Achilles heel, so to speak, seems to have been a combination of too much love for Gondor (to the point that the good of Gondor became more important to him than anything else) and the jealousy that arose from his rivalry with Thorongil/Aragorn. He had the right to use the palantir of Minas Tirith, and the wisdom to use it for the good of his country rather than his own profit, but he did not take into consideration the greater power of Sauron. Even as he attempted to use the stone to ferret out the possible weaknesses of his Enemy, Sauron was doing the same to him, without him apparently knowing it.

Was Denethor insane? Quite likely. But was his insanity the result of his pride? Perhaps in part, but certainly not in whole. Sauron manipulated what he saw to drive him to despair, and it was the ultimate despair of seeing his only remaining son on the brink of death while his city was under siege that pushed him over the edge, I think.

Just my two cents, as always.