Larner asked for Frodo and Aragorn having an argument. This slots into that period of time between the naming of the members of the fellowship and their departure. I can't say this turns out any better than the debate between Elrond and Gandalf, but it's not clear, on a practical level, how it could.
"—said, have you anything to say, Frodo?"
Frodo blinked, and jerked slightly, then looked up into the faces of his two companions. Gandalf and Strider—Aragorn, he reminded himself—were gazing at him expectantly. Alas, the last thing Frodo could recall, they had been debating the journey South, but a quick glance down at the map showed markers on the trail through Rohan, about which he knew nothing. Not even the question at hand!
"I'm sorry," he replied, chagrined, "I fear I must have been nodding off! What hour is it?"
"It is late," Aragorn conceded, and glanced at Gandalf. "Perhaps we should end our deliberations for the day."
"No doubt," the wizard replied, rising and stretching. "In the end," he sighed, "all our plans may come to naught, as the fortune of the world shapes things. Best we not quarrel too much over matters that we cannot afford to cling to. A good night to you both—rest well, and enjoy the mattresses while you may!"
With that, Gandalf departed, leaving Aragorn to roll the map carefully up and return it to its case and place among the books of Elrond's library. Frodo picked up the markers, turning the tiny, smooth stones in his hands. "Nine walkers and nine riders," he murmured, and shook his head. "Are we really leaving in a week? It seems only yesterday we arrived!"
"It is always thus—time runs more swiftly with a task before one," Aragorn replied, as he rejoined the hobbit.
"Until one begins, and then it seems time goes very slowly indeed, when the task is unpleasant," Frodo said and sighed. At that, Aragorn grunted softly, and he sank down onto one of the stools they had perched upon, leaning his elbows on the tabletop as he looked at Frodo, and there was something at work behind those grey eyes. Frodo cocked his head. "What is it?" he asked.
"There is somewhat I have been meaning to ask you, and I would have your plainest answer, and your best. For I am not easy in my mind about this company, over late though it may be to entertain such worries."
"It does seem a late concern. I thought all was decided," Frodo replied, somewhat surprised, and got a shrug.
"Not all decisions stand in the face of necessity," Aragorn answered. "And with so few as we shall be, 'tis better to make changes even now than live with our regrets later on."
"What changes? No, wait," Frodo stopped the other before he could even begin, for late though the hour was in all senses of the word, it needed but a moment's reflection to guess what must be on the Ranger's mind. "Is this about Merry and Pippin?"
"Were it my choice, I would still send them back—and this time under better care than one Ranger can provide," Aragorn replied.
"Do not think I have not tried to persuade them," Frodo said. "But they will not be swayed, and they have come this far, after—"
"I know that," Aragorn interrupted, abruptly. "And I do not make light or little of that feat, but that is no reason to let them go further, when there are others with far greater experience of the perils we shall face. 'Tis your best answer I need, Frodo, not the one that appeals to the heart."
"But I haven't got another!"
"Then why should I not press my case with Elrond to find two others to replace them?" Aragorn demanded quietly.
"What of Gandalf's counsel?" Frodo asked after a moment. "You seemed to accept what he said."
"'Seemed,'" Aragorn replied. "We have spoken of it."
"We still speak of it," came the frank admission.
"I see." Frodo paused a moment, frowning. Then: "Why have you not spoken to me of this until just now?"
"You will forgive me for saying it, I hope, but you had not seemed to wish for much part in any planning," Aragorn replied.
Which was true, and Frodo felt his face heat a little, though in point of fact, if the road to Rivendell had taught him anything, it was that overseeing so great a journey, through lands so strange to him, put him as far out of his depth as maps did Sam Gamgee. And the others had seemed content to manage matters, too… "If that is so—and I do not deny it—then why do you ask me?" he demanded, honestly perplexed.
"Because in our latest contest over the inclusion of Merry and Pippin, Gandalf said finally that he would have them because he felt that you would have need of them one day. So I would know, Ring-bearer: is he right?"
Is he? Frodo wondered, feeling a bit unfairly caught in the web of his loyalties. For glad as he was to think of having familiar company, he knew very well that he ought, for Pippin's and Merry's sake, to wish them well away from what awaited them in the far lands. Too, there was the fact that however secret their journey, a few more swords, in hands that knew how to handle them, likely would not go amiss, and there he knew that not only Merry and Pippin were a liability. Then again, Gandalf's counsel was hardly to be rejected out of hand. But on the other hand, it was somewhat demeaning to think his own desires were being argued over by friends who had never consulted him on the matter until just now!
But however belated, the question had come down to him, and it was simple enough: was Gandalf right to think he had need of his cousins on so dangerous a journey? Frodo stared at the Man sitting across from him, who said nothing but waited upon an answer. My best answer. It would be easy to say 'yes' and have done with it and all questions about Merry and Pippin. But Strider had not asked for the easy answer, either.
And so at length he replied: "What I know of such quests as this, and of lands beyond the Shire, comes not from any experience of them—it is all book-learning, as we say. I do not doubt that you and Gandalf and Elrond know better than I what is involved, what we shall need and who could meet such needs. Perhaps you are better, too, at finding your feet among strange folk than I am. And there's no doubt that Gandalf knows many more things and sees more clearly what folk think and want than I ever shall. I have to say, I don't know what he means when he says I shall need them one day."
At that, Aragorn raised a brow. "Do you not?" he asked.
"No, I do not," Frodo replied. But he hastened then to add: "But this I do know: I would not have come even so far as Bree without them. It was Merry and Pippin and Sam who started things, who saw through me and got me going sooner than ever I had thought I could manage—and just in the nick of time. I don't know what might happen in the future—whether there shall be another chance for them to move me onward like that—but you said it yourself: necessity could change everything.
"And so Gandalf is right that we shouldn't count on what's likely, since fortune might intervene. After all," Frodo pointed out, "'twas fortune put the Ring in the hands of a hobbit. Who is to say what may arise that may need Merry or Pippin to see to it?"
Aragorn was silent for a time, his gaze intent as he considered this response. But then he sighed and bowed his head. "Who indeed?" he replied. Then, giving Frodo one of his long looks: "So be it. I will say no more, but wish you a good night."
With that, he rose, and waited until Frodo had climbed down from his perch, then walked him to the door of the library. And there, Frodo stood and watched him make off down the hall, until the Ranger was verily upon the end of it and the corner he must take. Then Frodo called out: "Aragorn!"
Aragorn paused, turned back, quizzically.
"I know it is less of an answer than you wished for, but it is all I have," he insisted quietly.
A soft laugh greeted this, as that grey-eyed gaze fell heavy upon him once more, 'til Frodo had to wonder what he saw there. But then: "'Tis more of one than you imagine. Good night, Frodo." And with that, the other was gone.