Then Pippin stabbed upwards, and the written blade of Westernesse pierced through the hide and went deep into the vitals of the troll, and his black blood came gushing out. He toppled forward and came crashing down like a falling rock, burying those beneath him. Blackness and stench and crushing pain came upon Pippin and his mind fell away into a great darkness.
'So it ends as I guessed it would,' his thought said, even as it fluttered away, and it laughed a little within him ere it fled, almost gay it seemed to be casting off at last all doubt and care and fear. And even then as it winged away into forgetfulness it heard voices, and they seemed to be crying in some forgotten world far above:
'The Eagles are coming! The Eagles are coming!'
For one moment more Pippin's thought hovered. 'Bilbo!' it said. 'But no! That came in his tale, long, long ago. This is my tale, and it is ended now. Good-bye!' And his thought fled far away and his eyes saw no more.
What first drew my attention here is the peculiar use of 'thought' in the second and fourth paragraphs, which is quite similar to its use in the famous scene in which Gollum's two 'thoughts' struggle with each other while Sam listens, fascinated and appalled (TT 4.ii.632-34). While there 'thought' seems very close to what we would call 'personality,' here 'consciousness' is a better fit. The word 'consciousness' did not enter English before the 17th Century, and the meaning in question here -- 'the totality of the impressions, thoughts, and feelings, which make up a person's conscious being. In pl. = conscious personalities' (OED sv. 5, emphasis original) -- seems to have awaited the invention of Locke. Given Tolkien's linguistic predilections, it is not hard to see why he would have preferred 'thought', since MED þoht (3c, d) offered the requisite meanings.
I am as yet, however, unaware of any use of þoht to describe situations similar to those we see in these two passages of Tolkien. (If any reader knows of one, please, do let me know.) So I began to think that perhaps I should look for passages with similar elements. Almost immediately Chaucer's Troilus and Criseyde came into my mind, specifically the scene in which Troilus dies:
1800 The wraththe, as I began yow for to seye, Of Troilus, the Grekes boughten dere; For thousandes his hondes maden deye, As he that was with-outen any pere, Save Ector, in his tyme, as I can here. 1805 But weylawey, save only goddes wille, Dispitously him slough the fiers Achille. And whan that he was slayn in this manere, His lighte goost ful blisfully is went Up to the holownesse of the seventh spere, 1810 In convers letinge every element; And ther he saugh, with ful avysement, The erratik sterres, herkeninge armonye With sownes fulle of hevenish melodye. And doun from thennes faste he gan* avyse 1815 This litel spot of erthe, that with the see Embraced is, and fully gan* despyse This wrecched world, and held al vanitee To respect of the pleyn felicitee That is in hevene above; and at the laste, 1820 Ther he was slayn, his loking doun he caste; And in him-self he lough right at the wo Of hem that wepten for his deeth so faste; And dampned al our werk that folweth so The blinde lust, the which that may not laste, 1825 And sholden al our herte on hevene caste.
(Troilus and Criseyde, V.1800-1825)
Now clearly Pippin's experience here is meant to remind us first of all of Bilbo's at the Battle of Five Armies, when the Eagles came and Bilbo was knocked unconscious, but woke to find himself 'not yet one of the fallen heroes' (Hobbit 298-99). But there's more to it than that. Bilbo has no 'thought' as he loses consciousness. His reflections come after he revives.
What happens to Pippin's 'thought' is far more like the experience of Troilus' 'goost': both of them laugh and undergo a profound change in attitude towards the troubles of the world of which they are letting go. Each of them believes his tale is over. True, Pippin is not in fact dying, but he thinks he is. So, the contrast between him and Troilus is also noteworthy. His 'thought' flies 'away', but Troilus' 'goost' rises heavenward. Troilus looks back down at the 'woe / of hem that wepten for his deeth so faste' and dismisses it; Pippin hears the 'voices...crying from some forgotten world above' (emphasis added) and dismisses them and the hope the coming of the Eagles should offer. These directions reflect the differences in world view in each work. Chaucer's Troy is Medieval and Christian, whereas Tolkien's Middle-earth is pre-Christian and without any concept of a heaven above. Hence also Tolkien drew on a word like þoht rather than 'goost'. Whether hobbits have any notion at all of a continued existence after death is unknown and doubtful. And perhaps as a final bit of the absurdity that has often attended this once 'fool of a Took', Pippin is ignominiously squashed by a troll he has killed himself, while Troilus, a great warrior, is killed by the greatest of all warriors. In both cases, however, the dignified serenity both Troilus and Pippin attain with their last thoughts is remarkable. For neither of them could be said to have possessed that before.