“In Bīt Mēseri and Berossos, where there are narratives connected to the names, it is clear that the apkallus were those who brought humankind the basic wisdom needed to establish civilization. This is written out in a full story in Berossos; the same is referred to in Bīt Mēseri in the phrase “plans of heaven and earth.”
In both places the first apkallu Uan/Oannes is most prominent in this matter. They both concur with the D fragment of the Adapa Myth, where Adapa is given insight into the secrets of both heaven and earth, the whole of Anu’s domain.
We observe in the lists, however, that there is not only a division between the first group of seven apkallus and the subsequent sages / scholars; there is also continuity. This seems to be the whole idea of extending the list of seven with subsequent scholars. The subsequent scholars belong to a tradition going back to the antediluvian apkallus.
There are variations in how this is expressed. The system is most clear in the Uruk tablet, which changes the designation from apkallu, mostly reserved for sages before the flood, to ummanu, the self-designation of the scholars preserving their wisdom after the flood.
But there is a very interesting hint in Bīt Mēseri as well. Lu-Nanna, the last apkallu in the list after the flood, is two-thirds apkallu. Here there is clearly a second point of transition–we must presume this time from apkallus to scholars.
This is confirmed in another short notice about Lu-Nanna in Bīt Mēseri: he lived during the time of Šulgi. Here, when the power of the apkallus fades, we are for the first and only time in Bīt Mēseri placed in real history. Šulgi is attested as a historical king; he reigned during the third dynasty of Ur (2094-2047 BCE).
Thus, at the brink between legendary time and historical time comes the transition from the mythical and legendary apkallus to the historical ummanus.
This clear tendency in the lists is confirmed by several witnesses from Late Assyrian kings stretching down to the last Babylonian king Nabonidus. The witnesses both attest that there was a special quality connected to wisdom from before the flood, and that this was the wisdom brought to humankind through the apkallus.
The king needed access to this kind of “higher” wisdom, which included insight into the divine secrets, in order to reign. Those responsible for providing the king with this kind of wisdom were the ummanus attached to the royal court. The wisdom one brought to humankind by the apkallus accordingly had a political dimension.
The ummanus provided the king with the wisdom necessary to rule the empire. The myth about the transmission of divine wisdom became part of an imperial ideology.
This wisdom became in the course of the first millennium not only oral, but written. There are numerous examples of how especially compositions belonging to the secret lore of the ummanus were ascribed to the apkallus, above all to the first of them, Uanadapa.
Here we can observe the same chain of transmission as in the lists. There is a general tendency to ascribe compositions of high authority to Ea and to Adapa, or other apkallus, as the second link in the chain.
Moreover, there is a tendency to use a language of revelation in the transmission from Ea to Adapa. In a manner like Kabti-ilāni-Marduk the god “showed” the heavenly wisdom to Adapa, who wrote it down on tablets. Or, as in the case of Nabonidus, he was even wiser than Adapa, because the god had revealed to him the divine secrets.
This notion is in line with a broader tendency from the end of the second millennium, to date compositions back to the mythical primeval time, the time before the flood.”
Helge Kvanvig, Primeval History: Babylonian, Biblical, and Enochic: An Intertextual Reading, Brill, 2011, pp. 154-5.