[HerenIstarion]

I will go on providing you with quotes [img]smilies/smile.gif[/img]

But the promise made to the Eldar (the High Elves – not to other varieties, they had long before made their irrevocable choice, preferring Middle-earth to paradise) for their sufferings in the struggle with the prime Dark Lord had still to be fulfilled: that they should always be able to leave Middle-earth, if they wished, and pass over Sea to the True West, by the Straight Road, and so come to Eressëa – but so pass out of time and history, never to return. The Half-elven, such as Elrond and Arwen, can choose to which kind and fate they shall belong: choose once and for all. Hence the grief at the parting of Elrond and Arwen.
But in this story it is supposed that there may be certain rare exceptions or accommodations (legitimately supposed? there always seem to be exceptions); and so certain 'mortals', who have played some great part in Elvish affairs, may pass with the Elves to Elvenhome. Thus Frodo (by the express gift of Arwen) and Bilbo, and eventually Sam (as adumbrated by Frodo); and as a unique exception Gimli the Dwarf, as friend of Legolas and 'servant' of Galadriel

from the letter to Naomi Mitchinson (L154 25 September 1954)

italics mine