Oddly enough, all this latest talk in my commentbox of the European Urnfield culture and Etruscan cremation practices led me to thinking about Egyptian beliefs about the afterlife. I suppose that lacking comprehensive resources on the Etruscan concept of death and afterlife, something which I doubt exists yet, I look to the Egyptians for even a shade of insight, particularly since there are so many connections to be made. (Remember that the Etruscans used scarabs as tomb offerings directly proving that they were affected by Egyptian beliefs in some form or fashion.)
Now, as I understand it, the Egyptian spirit is often said to be divided into three parts: the ka, the ba and the akh . These names are modern Budgisms based on the vowelless spelling of the Egyptians but I gather that they were pronounced more like *kuˀ, *baˀ and *ˀaḫ respectively at around 1500 BCE. I notice the Wikipedia under Egyptian soul currently claims there are five components of the Egyptian soul but then piles on even more concepts in its schizophrenic, multi-author account. Added is the sheut 'shadow' (or rather *šawīt), the ib 'heart' (*ˀib) and the ren 'name' (more accurately *rin), helping to thoroughly confuse the reader rather than elucidate. I consider these last three related but incidental to the fundamental Egyptian notion of 'soul'. In the following I want to explore a new idea that came to me.
The ka is sometimes translated 'soul', sometimes 'image' and sometimes 'double'. Many other translations are also attempted. Yet I wonder recently if this odd translation confusion exists because this term wasn't just referring to the spirit itself as modern theologians might understand it but instead to the containment of the spirit in a vessel, a vessel such as a body or statue. If so, this gives a whole new nuance to the *Ḥáˀat-Kuˀ-Patáḥ, a famous temple in the city of Memphis. It would then suggest that this temple wasn't just housing the 'soul of Ptah' (*kuˀ Patáḥ) but that it was so named because it was believed, at least by its cult leaders, to be the temple in which the very body *and* soul of Ptah was present. This gives me a vision of a grand building within which an impressive, monumental statue of Ptah sits, around which rituals were enacted by its devout priesthood as if he were the living article, all for the wonder of the entranced commonfolk. Such a subtle notion of the word *kuˀ would emphasize this particular temple's central importance to the worship of this god of death and resurrection. Why go to just any temple of Ptah when one can experience Ptah's holy spirit 'in the flesh'? It would certainly have been great temple marketing if my perception here is realistic.
Also by reconceiving of the ka as the 'soul' specifically when contained in its physical manifestation rather than just 'soul' proper, contrastively then the ba must be the spirit itself, particularly when it was separate from the *ẖīˀat or body. It would be the ba, I think, that is most appropriately translated as the English-speaking notion of 'soul'. So maybe we can get away with thinking of the ba as a *subset* of the ka rather than on a par with it.
This theoretical structure of an ancient belief system leads me to wonder if the akh was in turn yet another subset (of the ba, that is). In the resulting reinterpretation, the soul really isn't divided into three parts, or even five. Instead the soul is composed of three layers with the akh, as 'life-force' or 'will', being the innermost of the three metaphysical strata. In this ontology, the 'will' (akh) is a component of the 'soul' (ba) which is further merely an ingredient in the union of body and soul (ka).
I'll have to explore this idea further and see what evidence is in its favour or against it.