Why did Aragorn change his mind about the Rohan tribute rumor?

Question

At the Council of Elrond, Gandalf relates a rumor that Rohan tributes horses to Mordor:

'"Are the men of Rohan still to be trusted, do you think?" I said to Gwaihir, for the treason of Saruman had shaken my faith.

'"They pay a tribute of horses," he answered, "and send many yearly to Mordor, or so it is said; but they are not yet under the yoke."

Aragorn worries that this may be true, but Boromir dismisses the possibility:

'Then he must be a noble beast indeed,' said Aragorn; 'and it grieves me more than many tidings that might seem worse to learn that Sauron levies such tribute. It was not so when last I was in that land.'

'Nor is it now, I will swear,' said Boromir. `It is a lie that comes from the Enemy. I know the Men of Rohan; true and valiant, our allies, dwelling still in the lands that we gave them long ago.'

`The shadow of Mordor lies on distant lands,' answered Aragorn. 'Saruman has fallen under it. Rohan is beset. Who knows what you will find there, if ever you return?'

`Not this at least.' said Boromir, 'that they will buy their lives with horses. They love their horses next to their kin.'

Months later, Aragorn still has his doubts about Rohan's allegiance when discussing the route of the Fellowship after the ascent up Caradhras has failed:

"Further south there are no passes, till one comes to the Gap of Rohan. I do not trust that way since your news of Saruman. Who knows which side now the marshals of the Horse-lords serve?"

But upon reaching Rohan, this dialogue occurs:

'But Gandalf spoke of a rumor that they pay tribute to Mordor,' said Gimli

'I believe it no more than did Boromir,' answered Aragorn.

Is any explanation given for why Aragorn entertained the rumor in Rivendell and Hollin but dismissed it in Rohan?

Answer 1

Aragorn had his doubts about the Rohirrim based on rumors, but Boromir convinced him that they were baseless

Aragorn himself had been in the region and even served in the armies of Rohan somewhere between T.A.¹ 2957 - T.A. 2980 so he knew the Rohirrim well:

[years T.A.] 2957-80 Aragorn undertakes his great journeys and errantries. As Thorongil he serves in disguise both Thengel of Rohan and Ecthelion II of Gondor._{~J.R.R. Tolkien, The Lord of the Rings, Appendix B, The Third Age}

but it was a long time ago, and at the council of Elrond (held on 25 October, T.A. 3018 in Rivendell) he feared that the Rohirrim since then became corrupted by Sauron. Boromir, however, who was from that region, had more recent news and was familiar with the Kingdom of Rohan, vehemently denied the rumors, attributing them to the deceit of the Enemy²:

Nor is it now, I will swear,' said Boromir. `It is a lie that comes from the Enemy.'_{~LoTR, The Fellowship of the Ring - Book II, Chapter 2: The Council of Elrond}

Boromir, the trusted son of the serving Steward of Gondor, the longtime ally of Rohan had more fresh information than Aragorn, and he vouched for the Rohirrim. It is reasonable that Aragorn believed him and not some rumors that reached the remote Rivendell and who knows what was added them in the telling and who started them in the first place.

Boromir also argued that they would never trade their horses:

`Not this at least.' said Boromir, 'that they will buy their lives with horses. They love their horses next to their kin.' _~(ibid)

Another good argument, which probably reminded Aragorn how much the riders of Rohan valued their steeds, and how ridiculous the rumor is.

Aragorn was convinced by Boromir. After all, a reasonable person lets himself be convinced if the arguments are sound instead of clinging to his own opinion. It is a good quality, especially in a (future) king.

Later Gimli, who was present at the council meeting, reminds him of the rumor:

'But Gandalf spoke of a rumor that they pay tribute to Mordor,' said Gimli _{~LoTR, Two Towers, Book III - Chapter 2: The Riders of Rohan}

And Aragorn indicates that he shares Boromir's opinion:

'I believe it no more than did Boromir,' answered Aragorn. _~(ibid)

Later Gimli verifies that the rumors are indeed baseless:

'Then you do not pay tribute to Sauron?' Said Gimli. 'We do not and we never have' said Jomer with a flash of his eyes; Through it comes to my ears that that lie had been told. Some years age the Lord of the Black Land wished to purchase horses of us at a great price, but we refused him for he puts beasts to evil use. Then he sent plundering Orcs, and they carry off what they can, choosing always the black horses: few of those now left. For that reason our feud with the Orcs is bitter. _~(ibid)

<sub>1. Third Age
2. Sauron</sub>

Answer 2

I think the wording in The Council of Elrond is not as clear as it should have been. When Aragorn says

it grieves me more than many tidings that might seem worse to learn that Sauron levies such tribute.

_{The Lord of the Rings Book Two, Chapter 2: The Council of Elrond
Page 262 (Single volume 50th Anniversary Edition)}

What he has "learned" is that Gwaihir had told Gandalf that "it was said" that Rohan paid tribute to Sauron. Aragorn adds that it was no so the last time he was there, and Boromir insists that it cannot be so.

Aragorn does not dispute Boromir's assessment. As he says later that he didn't believe the rumour about tribute, I think we must take him at his word. In that case, his statement at the Council should have been more like "it would grieve me more than many tidings ...". Perhaps he phrased the sentence badly, or perhaps the author of the Red Book misquoted him.

Answer 3

It doesn't offer much insight into Aragorn's mind in the final product, but it's interesting to note that the doubts are present as early as Rohan itself in Tolkien's drafts, and apparently more reasonable to hold. The very first appearance of Rohan has it as outright villainous:

'I think no good of any part of our course, as you know well, Master Peregrin,' snapped Gandalf. 'Still we have to go on. It is no good whatever our trying to cross further south in the land of Rohan. The Horse-kings have long been in the service of Sauron.'

-The Return of the Shadow, "The Ring goes south"

Later drafts returning to the Council of Elrond abandon Rohan being longstanding evil, but are far less kind than the Lord of the Rings. Neither the eagle nor Aragorn (originally Elrond) express any doubt that the tribute is real, nor does Boromir rise to Rohan's defense:

"They pay tribute...yearly in horses to Mordor," said Gwaewar, "but they are not yet under the yoke;

'He is indeed a fine steed,' said [Elrond >] Aragorn; 'and it grieves me that Sauron should have such tribute'

-The Treason of Isengard, "The Council of Elrond (1)"

As the later drafts revisit Hollin, Rohan's allegiance is questioned, though originally by Gandalf, whereas Trotter (before Aragorn's nickname was changed to Strider) merely agrees with him:

Further south there are no passes, till one comes to the Gap of Rohan. I do not trust that way, since the fall of Saruman. Who knows which side now the marshals of the Hose-lords serve? 'Who knows indeed!' said Trotter. 'But there is another way

-The Treason of Isengard, "The Ring goes south"