In some forms of thought, evil is also sometimes perceived as the dualistic antagonistic binary opposite to 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 "Nirvana". The ethical questions regarding good and evil are subsumed into three major areas of study: meta-ethics concerning the nature of good and evil, normative ethics concerning how we ought to behave, and applied ethics concerning particular moral issues. While the term is applied to events and conditions without agency, the forms of evil addressed in this article presume one or more evildoers.