In religion, ethics, philosophy, and psychology "good and evil" is a very common dichotomy. In cultures with Manichaean and Abrahamic religious influence, evil is perceived as the dualistic antagonistic opposite of good, in which good should prevail and evil should be defeated. In cultures with Buddhist spiritual influence, both good and evil are perceived as part of an antagonistic duality that itself must be overcome through achieving Śūnyatā meaning emptiness in the sense of recognition of good and evil being two opposing principles but not a reality, emptying the duality of them, and achieving a oneness. Evil is often used to denote profound immorality. Evil has also been described as a supernatural force. Definitions of evil vary, as does the analysis of its motives. However, elements that are commonly associated with evil involve unbalanced behavior involving expediency, selfishness, ignorance, or neglect. The modern philosophical questions regarding good and evil are subsumed into three major areas of study: metaethics concerning the nature of good and evil, normative ethics concerning how we ought to behave, and applied ethics concerning particular moral issues. Every language has a word expressing good in the sense of "having the right or desirable quality" (ἀρετή) and bad in the sense "undesirable". A sense of moral judgment and a distinction "right and wrong, good and bad" are cultural universals. The philosopher Zoroaster simplified the pantheon of early Iranian gods into two opposing forces: Ahura Mazda (Illuminating Wisdom) and Angra Mainyu (Destructive Spirit) which were in conflict. This idea developed into a religion which spawned many sects, some of which embraced an extreme dualistic belief that the material world should be shunned and the spiritual world should be embraced. Gnostic ideas influenced many ancient religions which teach that gnosis (variously interpreted as enlightenment, salvation, emancipation or 'oneness with God') may be reached by practising philanthropy to the point of personal poverty, sexual abstinence (as far as possible for hearers, total for initiates) and diligently searching for wisdom by helping others.