Ringwraiths

Invisible, but corporeal

Yvette Kisor, a scholar of literature, writes that while the Ringwraiths and others (like Frodo) who wear Rings of Power become invisible, they do not lose any of their corporeality, being present as physical bodies. They require, she writes, physical steeds to carry them about, and they can wield swords. She notes that only a person in a body can wield the One Ring, so the invisibility is just "a trick of sight". When Frodo, wearing the Ring, saw the Nazgûl in the "twilight world", they appeared solid, not shadowy. He also saw Glorfindel in that world, as a figure of white flame; and Gandalf explains later that the Ringwraiths were "dismayed" to see "an Elf-lord revealed in his wrath". Frodo is in danger of "fading" permanently into invisibility and the twilight world, as the Ringwraiths have done, living "in another mode of reality". She writes, too, that Merry's sword, with the special power to sever the Witch-king's "undead flesh" and in particular to overcome the "spell that knit his unseen sinews to his will", has in fact to cut through real, but invisible, sinews and flesh.