Dualistic cosmology is a collective term. Many variant myths and creation motifs are so described in ethnographic and anthropological literature. These motifs conceive the world as being created, organized, or influenced by two demiurges, culture heroes, or other mythological beings, who either compete with each other or have a complementary function in creating, arranging or influencing the world.
There is a huge diversity of such cosmologies. In a Chukchi example, the two beings do not compete, rather collaborate. They contribute to the creation in a coequal way. They are neither collateral nor consanguineous relatives. In many other instances the two beings are not of the same importance or power (sometimes, one of them is even characterized as gullible). Sometimes they can be contrasted as good versus evil. They may be often believed to be twins or at least brothers.
Dualistic motifs in mythologies can be observed in all inhabited continents. Zolotaryov concludes that they cannot be explained by diffusion or borrowing, but are of convergent origin: they are related to a dualistic organization of society (moieties); in some cultures, this social organization may have been ceased to exist, but mythology may preserve memories in more and more disguised ways.
Gnosticism is a diverse, syncretistic religious movement consisting of various belief systems generally united in the teaching that humans are divine souls trapped in a material world created by an imperfect god, the demiurge, who is frequently identified with the Abrahamic God. The demiurge may be depicted as an embodiment of evil, or in other instances as merely imperfect and as benevolent as its inadequacy permits. This demiurge exists alongside another remote and unknowable supreme being that embodies good.