If Denethor hadn't committed suicide

[Inziladun]

Originally Posted by The Mouth of Sauron

If Denethor had lived after the Battle of the Pelennor Fields and been introduced to Aragorn, he would have remembered him as Thorongil. And he might legitimately have asked Aragorn why, if his claim to the Kingship was genuine, he didn't press that claim when he served Denethor's father under the guise of Thorongil.

Interesting. I think the knowledge that 'Thorongil' was truthfully Aragorn probably did belong to Denethor, and that would have played a part in his contesting Aragorn's claim, since Denethor had been jealous of Thorongil's fame and influence with Denethor's father, Ecthelion II.
What would Aragorn's response to Denethor pressing him on that have been? Perhaps something like 'The time was not yet right, Lord Steward. I myself was not ready for the burden, nor had I yet earned it'. I suspect though, that no fair words or deeds on Aragorn's part would have reconciled Denethor to the idea of relinquishing his power and watching Aragorn rule.