Mandaeism or Mandaeanism (Arabic: mndy'y@ Manda'iyah) is a gnostic religion with a strongly dualistic worldview. Its adherents, the Mandaeans, revere Adam, Abel, Seth, Enos, Noah, Shem, Aram, and especially John the Baptist. The Aramaic manda means "knowledge", as does Greek gnosis. According to most scholars, Mandaeaism originated sometime in the first three centuries AD, in Mesopotamia.
Cosmology
As noted above Mandaean theology is not systematic. There is no one single authoritative account of the creation of the cosmos, but rather a series of several accounts. Some scholars, such as Edmondo Lupieri, maintain that comparison of these different accounts may reveal the diverse religious influences upon which the Mandaeans have drawn and the ways in which the Mandaean religion has evolved over time.  In contrast with the religious texts of the western Gnostic sects formerly found in Syria and Egypt, the earliest Mandaean religious texts suggest a more strictly dualistic theology, typical of other Iranian religions such as Zoroastrianism, Zurvanism, Manichaeism, and the teachings of Mazdak. In these texts, instead of a large pleroma, there is a discrete division between light and darkness. The ruler of darkness is called Ptahil (similar to the Gnostic Demiurge), and the originator of the light (i.e. God) is only known as "the great first Life from the worlds of light, the sublime one that stands above all works." When this being emanated, other spiritual beings became increasingly corrupted, and they and their ruler Ptahil created our world. The name Ptahil is suggestive of the Egyptian Ptah--the Mandaeans believe that they were resident in Egypt for a while--joined to the semitic El, meaning "god".  The issue is further complicated by the fact that Ptahil alone does not constitute the demiurge but only fills that role insofar as he is the creator of our world. Rather, Ptahil is the lowest of a group of three "demiurgic" beings, the other two being Yushamin (a.k.a. Joshamin) and Abathur. Abathur's demiurgic role consists of his sitting in judgment upon the souls of mortals. The role of Yushamin, the senior being, is more obscure; wanting to create a world of his own, he was severely punished for opposing the King of Light. The name may derive from Iao has-sammayim (in Hebrew: Yahweh "of the heavens").

Q: What was his relationship with Cosmology?
A: There is no one single authoritative account of the creation of the cosmos, but rather a series of several accounts.

Q: What were some of the accounts?
A: In these texts, instead of a large pleroma, there is a discrete division between light and darkness.

Q: What divides them?
A: The ruler of darkness is called Ptahil (similar to the Gnostic Demiurge), and the originator of the light

Q: Can you elaborate on this?
A: When this being emanated, other spiritual beings became increasingly corrupted, and they and their ruler Ptahil created our world.
Around what time were these theories created?
unknown
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