WordWheel: soul, spirit
Perhaps it is appropriate to start the roll of WordWheel with these words that take such a central place in Tolkien's writings. The fate of the soul, the core of the sentient being, its nature, its relation to the earthly matter that comprises our bodies is a subject of many a speculation in his works.
Soul and spirit. One a pleasant, almost jovial and rotund, suggesting something that is round and complete; the other conveys the hiss of the breath escaping from the mouth but also evokes images of stirring and movement. Sawol it was in Old English, with cognates found in the other Germanic tongues (Seele in German, saiwala in Gothic, to name a few). Its etymology is uncertain, but EtymOnline tantalisingly suggests "'Sometimes said to mean originally "coming from or belonging to the sea,' because that was supposed to be the stopping place of the soul before birth or after death. Hence, from P.Gmc. *saiwaz (see sea)" - a beautiful image, so Tolkienian in its spirit (pun intended) that I wonder why he did not incorporate it into his vision (it evokes images of dead, heathen Kings sliding into the sunset in their burning ships, like Beowulf or like it happened in Sutton Hoo, except of course Sutton Hoo is on the East coast, so the sunset bit is a bit dubious); provided, of course, that he knew about it.
Spirit goes a bit further back, via Latin spirare 'breathe', said to be from a PIE root *(s)peis- 'to blow', although I could not find the latter in any PIE root-list1 on the net (or just have not looked hard enough).
One should also mention the Latin anima here, also meaning - among others - 'soul, spirit', coming from PIE *ane- (yes, you've guessed) 'blow, breathe', yielding Old English eðian 'breathe', Old Church Slavic vonja 'smell, breathe' (reminds me of Polish wącha 'smells'). Kind of unsurprising now that Hungarian has lélek for 'soul' and we also have a verb lélegzik, meaning - but of course - 'he/she breathes'. (For Finnish I found sielu which looks like a borrowing from Germanic to me.)
I have not found much of relevance in the Qenyaqetsa; there is OLME 'emanation, apparition, spirit', which evokes vague images of later ÑOL-, holme 'odour' (Cf. the O.C.S. gloss above), but probably without any solid ground. The Gnomish Lexicon however already plays on the theme of blith 'air, breeze, spirit' and blaith 'spirit' (page 23.), although the word-forms do not resemble the later ones. The mid-Qenya of the Etymologies on the other hand introduces the root THÚ-:
THU- puff, blow. Q súya- breathe; súle breath. Cf. Súlimo surname of Manwe (wind-god). N thuio breathe; thûl breath.
- and the Lord of the Rings Appendix closes the circle by glossing the tengwa thúle 'spirit', achieving the effect of having the sound an image of soul and the underlying sense of spirit. Quite remarkable.
It is interesting though that the word that will be the true 'spirit' of Tolkien's mythology, sc. fea (phaiā) comes from a root of a different meaning, PHAY-:
PHAY- radiate, send out rays of light. Q faina- emit light; faire radiance; ON phaire. Cf. Phay-anaro ‘radiant sun’ > Q Feanáro, ON Phayanȱr, N Feanoúr, Féanor. Cf. N foen radiant, white. [See SPAN.]
It is perhaps interesting to note here that in Hungarian fény means '(white) light', fehér (also fejér in dialects) means 'white', and I believe there is also a Finnish word of a similar form (**päivää??) and related meaning2.
Of course, as we can see above, PHAY- leads us to SPAN-, which then in turn takes us to PHAN- in Parma Eldalamberon 17 and the 7 1/2 pages of etymologic musings on whiteness, radiance, apparitions3, mind-pictures and raiments for the spirit... which takes us back to soul, and the following two lines from Beowulf, applicable to Tolkien's spirit:
... him of hreðe gewat
sawol secean soðfæstra dom
"From his heart his spirit departed to seek fate of the faithful"