[Gordis]

Originally Posted by skip spence

I think this is important to remember: one must never, I repeat, NEVER, touch a naked Nazgul.

There are some temptations that are irresistible. Curiosity killed a cat…

Originally Posted by Bêthberry

Perhaps another interesting question is why they are robed in the colours of Gandalf. After all, much is made of Gandalf's colours. What is the relationship of the wraith-world and that of the maiar? Was Tolkien running out of colours or is there some kinship of the spirit world?

I think everything in the Wraith World appears as shades of gray: grays and whites and blacks. But it is not a negative image like in photography, Morthoron: note the nazgul faces are white (positive image) so their robes are indeed white and grey, not black visualized in negative contrast. Moreover the quotes clearly tell that the white-and grey garments are beneath the black outer robes, not that those are the same robes viewed in a different way.
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I agree with Alfirin that the nazgul white and grey garments "obviously couldn't be real shrouds since the Nazugul never tecnically died till the Third Age".

Originally Posted by Alfirin

since we don't really know how the fading works (do they live breath and eat all of thier lives or are they more like zombies, dead bodies still animated by thier spirits)

We know some facts, however.
1.Nazgul didn't need to eat and rest:

Only the bodies of 8 horses were discovered; but also the raiment of the Captain. It is probable that the Captain took the one horse that remained (he may have had strength to withdraw it from the flood) and unclad, naked, invisible, rode as swift as he could back to Mordor. At swiftest he could not accomplish that (for his horse at least would need some food and rest, though he needed none) ere November had passed. RC p. 262 -Marquette MSS 4/2/36 (The Hunt for the Ring)

2. Nazgul didn't need to breathe. It can be implied by Gandalf being so very sure that not a single nazgul was drowned by the Flood at the Ford - which proved accurate.

3. Yet, not needing air, the nazgul could and did breathe.

From inside the hood came a noise as of someone sniffing to catch an elusive scent - "Three is company"
Frodo thought that he heard a faint hiss as of venomous breath -"The knife in the dark"
A breath of deadly cold pierced him like a spear - "Flight to the Ford"

I would venture the idea that it was likewise with food as well: the nazgul didn't need to eat to survive, but it doesn't mean they would turn down a nice juicy steak with a bottle of Nurn. Valar, after all, didn't need to eat either, yet they had one feast after another to the point of neglecting to watch their precious Trees.

Originally Posted by Alfirin

I personally think the fact that the Nazgul kings body more or less evaported when he was slain seems to indicate the latter, that ultimately the faded bodies simply disinegrate and what you have left is dust held in the form of a man by the Nazgul's fea (what frodo saw with the ring in this case would have been the nazgul's fea visualized, which would of course look like the Nazgul did in life (in the same way that a ghost can resemble the person it is a ghost of) we dont really know how solid a Nazgul's body is, Merry is the only one who actually stabbed into won and he was too distacted to note whether it felt like he hit something solid inside, or just empty armor.)

The fact that the nazgul bodies were maintained by Dark Magick doesn't mean the nazgul bodies were not solid or material. Merry didn't hit empty armor, there was "something solid inside" and we are told exactly what he had hit:

Merry’s sword had stabbed him from behind, shearing through the black mantle, and passing up beneath the hauberk had pierced the sinew behind his mighty knee. No other blade, not though mightier hands had wielded it, would have dealt that foe a wound so bitter, cleaving the undead flesh, breaking the spell that knit his unseen sinews to his will.

How can a fea have flesh and sinew? Flesh is hroa by definition. This particular hroa offered a lot of resistance to ordinary blades (Eowyn's had disintegrated on impact) and ordinary resistance to the Barrow-Down's blade - Merry's stab pierced the mantle and cut the ligaments behind a knee - nothing extraordinary here, given it was a small sword wielded by a hobbit.
So, I believe, on Weathertop Frodo saw not " the Nazgul's fea visualised" but their hroar, that now belonged to the Shadow World. And their hroar were the very ones the nazgul had been born with, only they gradually became invisible, faded.

For Men fading is an alien phenomenon, but for Elves it is an ordinary thing to happen if they stay too long in Middle Earth. Faded Elves, called "the Lingerers" are described in the "Laws and Customs among the Eldar" in Morgoth's Ring (Home X).

“the Lingerers, whose bodily forms may no longer be seen by us mortals, or seen only dimly and fitfully"
“Moreover, the Lingerers are not houseless, though they may seem to be. They do not desire bodies, neither do they seek shelter, nor strive for mastery over body or mind. Indeed they do not seek converse with Men at all, save maybe rarely, either for the doing of some good, or because they perceive in a Man's spirit some love of things ancient and fair. Then they may reveal to him their forms (through his mind working outwardly, maybe), and he will behold them in their beauty.”

Originally Posted by Lalwendë

I always think that the Ringwraiths are a constructed, twisted, mortal equivalent of the 'houseless fea'. Sauron's Rings clearly have an effect upon the hroa and fea of the bearer, and I think the rings he made for Men give a false impression of immortality by working on the nature of Men's being, even wearing their hroa to the point of invisibility or being as insubstantial as to barely exist. This was Sauron's way of making the seven bearers 'immortal' - their hroa are changed in nature so that they fade and do not die.

I have to disagree: nazgul are mortal equivalent of the Lingerers, not the Houseless Elves. The Houseless have no hroar at all: they are dead, their bodies had died, but their fëar refused to go to Mandos where they belong. The Nazgul and the Lingerers do have bodies invisible by mortals, but solid and not dead. They were never summoned to Mandos - just because they haven't died.

"Invisible" is not the same as "insubstantial". Imagine one walks by night, hits an invisible tree and finds it painfully substantial. Ordinary Men simply don't see at night, neither do they see in the World of Shadow - but that doesn't prevent them from hitting something invisible for them and getting hurt.