In that first segment, it seems that legend has it that Kadmos’ legendary palace became Thebes’ first temple to Demetre, which suggests that —assuming Thebans did, in fact, habitually syncretise Demetre with Erinys Telphousia— that while Kadmos’ task earned Ares’ wrath, it was still within the will of Demetre. This also solidifies my thoughts on Demetre as a Great Mother of Civilisation and sustainable urban planning. It also speaks to the kind of mother She truly is: While She certainly has Her loving and nurturing aspects (as should be obvious), She’s also pragmatic and realises that sometimes sacrifices must be made for the greater good, and sometimes what She has begotten is standing in the way of progress and must be eliminated.
While Her rural associations are impossible to escape, so too are Her urban aspects, as I noted before. Likewise, just as much as She values tradition, She also wills progress.
I’m now reminded of a bit from Edith Hamilton’s Mythology, suggesting that while every other deity in the Hellenic pantheon was borderline useless to Man, it was Dionysos and Demetre, agricultural deities, who stood alone in being beneficial. As problematic as Hamilton’s dismissal of other deities is, I can certainly see some similarities between the two, especially in Their domains of “opposing” values somehow united in harmony through Their guidance.
This comes back around to Kadmos, who (modern scholars argue) was initially a unique Boeotian cult hero, and later was syncritised with a Phoenician adventurer. From that story, the still-later symbolic mythology arose of Kadmos inventing the alphabet and introducing people to agriculture (further linking Kadmos and Demetre), and also becoming wedded to Harmonia, which is argued to symbolise the union of an “Eastern” love of learning with a “Western” love of beauty. How Kadmos’ mythology truly developed is lost to time, but the symbols clearly reiterate a union of apparent opposites, and also closely associate the hero with Demetre. Considering this, it therefore makes perfect sense that his palas was soon converted to a grand temple to Demetre.
Now, the archaeology only debatably confirms some of the folk beliefs about Kadmos, including the origin of the alphabet coinciding with the founding of Thebes. The Phoenecian alphabet wasn’t introduced to Hellas until after the estimated date for the Trojan War. While the modern Hellenic alphabet is clearly descended of Phoenecian script, a far older text, called “Linear B” amongst those who study these things, is on tablets that have been found in a disproportionate abundance in and around Thebes, and so this may coincide with Herodotus’ relaying of Kadmos’ founding of Thebes, and bringing his knowledge with him, as significantly pre-dating the Trojan War. Unfortunately, few symbols of Linear B, at best, resemble any form of the Hellenic alphabet known today, but clearly the Linear B writing system was widespread throughout Thebes.
Considering that this became widespread in Thebes from a most-direct origin of the palace of Kadmos, again, this seems to symbolically reiterate the associations of Demetre with Civilisation and urban development —no civilisation in Earth’s history, living or extinct, has ever developed cities without a system of writing. By this, we can infer that writing is also sacred to Demetre; oral tradition is too easily manipulated and can be problematic in its attempts to learn history. After all, the Cyrenaic school was on to something in pointing out that the only true source of potential knowledge we can have is experience, but they were also sceptical of this knowledge in that we cannot truly know the experiences of everything that led up to what we experience; thus oral history seems especially superficial. To gain a better understanding, if not true knowledge, of history, we can learn from the paper trails (and, in this modern era, other recordings) of what happened; this experience is, too, superficial, but has greater potential for understanding than oral traditions alone. Again, we see Demetre as a Goddess of balancing Tradition and Progress in a harmonious and sustainable whole.
I conclude that Kadmos was, thus, most likely a unique Theban hero later syncretised, and that this Theban hero, in all the feats attributed to him, was doing Demetre’s Work on Gaia’s face. Though the alphabet he introduced did not stand the tests of time, we cannot blame because a slightly younger script managed to flourish and Theban pride attributed it to him, anyway; the exacts become less important when the intention still manages to flourish.