Nondualism is the implication that things appear distinct while not being separate. The term “nondual” (meaning “not two”) can refer to a belief, condition, theory, practice, or quality. The concept of Nondualism has been linked with “Monism” or “qualified monism” with which it is sometimes confused (even conflated). However, the general concept of “nonduality” is now a pervasive paradigm in Western scholarship throughout diverse academic disciplines. Michaelson (2009: p. 130) writes:”Conceptions of nonduality evolve historically.”
“Nondualism”, “nonduality” and “nondual” are terms that have entered the English language from literal English renderings of “advaita” (Sanskrit: not-dual) subsequent to the first wave of English translations of the Upanishads commencing with the work of Müller (1823–1900), in the monumental Sacred Books of the East (1879), who rendered “advaita” as “Monism” under influence of the then prevailing discourse of English translations of the Classical Tradition of the Ancient Greeks such as Thales (624 BCE–c.546 BCE) and Heraclitus (c.535 BCE–c.475 BCE). The first usage of the terms are yet to be attested. The English term “nondual” was also informed by early translations of the Upanishads in Western languages other than English from 1775. The term “nondualism” and the term “advaita” from which it originates are polyvalent terms. The English word’s origin is the Latin duo meaning “two” prefixed with “non-” meaning “not”.