Every human society has notions of good (morally laudable) and bad (morally reprehensible) behavior. When these notions are elevated to be independent abstract principles we speak of good and evil, and some religious systems can be interpreted in terms of these two opposing powers, sometimes seen as constantly locked in combat with each other. The complexity of ancient Mesopotamian religions, resulting from the syncretism over many years of numerous local cults, was not conducive to such a view, evein if in the Standard Babylonian tradition and in Neo-Assyrian religion we occasionally come across personified concepts like Kittu (Truth, daughter of Samas/Utu) Misaru (Justice, sone of Samas) and Dyyanu (the Judge) as deities.

While the principal deities Enlil, Utu/Samas and Enki/Ea promote justice and activities beneficial to man, protect the weak, widows and orphans, and destroy the wicked, these are secondary characteristics of their divine personalities, rather than their personalities being an extension of their role as a personification of good. The ‘wicked’ are often not distinguished from the ‘enemy’. The Sumerian gods, amongst themselves, behave amorally, even immorally.

Many of the spirits we call ‘demons’, such as the udu, lama, alad or galla, were originally neutral, and the evil forms of them are specifically identified as ‘evil udugs’, ‘evil gallas’ (except that in certain contexts reference to evil form is taken for granted). Perhaps the nearest to a specifically evil personification in the Mesopotamian record is the demon often mentioned in magical incantations called Mimma lemnu, which means ‘All that is evil’. No information survives about how the physical features of this demon were envisaged.