How we cite our quotes: (Book.Chapter.Paragraph).
Quote #4
[Théoden] was silent. "Ents!" he said at length. "Out of the shadows of legend I begin a little to understand the marvels of the trees, I think. I have lived to see strange days. Long we have tended our beasts and our fields, built our houses, wrought our tools, or ridden away to help in the wars of Minas Tirith. And that we called the life of Men, the way of the world. We cared little for what lay beyond the borders of our land. Songs we have that tell of these things, but we are forgetting them, teaching them only to children, as a careless custom. And now the songs have come down among us out of strange places, and walk visible under the Sun." (3.8.70)
As Théoden points out here, the men of Rohan have a bad case of tunnel vision. They have been so occupied with their own business over the years that they have forgotten to look around them at the larger world. But clearly, this could also be taken as a larger critique of the way that contemporary people interact with folklore. Tolkien's work in life (besides Middle-earth) was the study of ancient Norse and Old English sagas and poems. These were tales of great deeds written for people of all ages. Now, many of the contents of those tales—dragons and gods and so on—are the stuff of kids' stories. Théoden admits, "Songs we have that tell of these things, but we are forgetting them, teaching them only to children, as a careless custom." One of the great tasks of the world of The Lord of the Rings is to redeem these children's stories, told "as a careless custom," for adults. Fantasy literature is all about taking things that seem absurd according to "the way of the world"—wizards and elves and so on—and using these folkloric elements to convey something more profound than you might expect from children's stories.
Quote #5
Understand one another? I fear I am beyond your comprehension. But you, Saruman, I understand too well. I keep a clearer memory of your arguments, and deeds, than you suppose. When last I visited you, you were the jailor of Mordor, and there I was to be sent. Nay, the guest who has escaped from the roof, will think twice before he comes back in by the door. Nay, I do not think I will come up. But listen, Saruman, for the last time! Will you not come down? Isengard has proved less strong than your hope and fancy made it. So may other things in which you still have trust. Would it not be well to leave it for a while? To turn to new things, perhaps? Think well, Saruman! Will you not come down? (3.10.45)
Saruman is now isolated in just about every way possible, as Gandalf points out here. He's literally trapped in a tower with no company other than Gross—oops we mean Gríma Wormtongue. But he is also figuratively isolated, in the sense that he has no friends, no master, and, quite frankly, no hope. But Saruman's troubles are less interesting to us than Gandalf's own new form of isolation. He fears that he is "beyond [Saruman's] comprehension." Honestly, he seems beyond the comprehension of anyone on the good side. He is not all-powerful, but he's still the strongest being in this book besides maybe Sauron, and it's lonely at the top.
Quote #6
For a moment it appeared to Sam that his master had grown and Gollum had shrunk: a tall stern shadow, a mighty lord who hid his brightness in grey cloud, and at his feet a little whining dog. Yet the two were in some way akin and not alien: they could reach one another's minds. Gollum raised himself and began pawing at Frodo, fawning at his news. (4.1.162)
Horrible he may be, but Gollum is a Ring-bearer just as Frodo is. In fact, he has held the Ring for a whole lot longer than Frodo ever will. They are strangely bonded by this experience, which isolates Sam, who can't quite understand it until he's a Ring-bearer himself. As Frodo starts to fall prey to the Ring (becoming more and more Gollum-like, unfortunately), Sam has to step in and give us a bit of sanity to hold onto as readers. After all, if Sam began to understand Frodo as well as Gollum does, he would be possessed by the Ring just like, well, almost everyone else.