Advaya, the identification of phenomena and the Absolute, the "nonduality of duality and nonduality",[web 3] or maybe the nonduality of relative and ultimate real truth as located in Madhyamaka Buddhism and the two truths doctrine. Mahadevan suggests that Gaudapada adopted Buddhist terminology and adapted its doctrines to his Vedantic aims, https://acim.biz/a-course-in-miracles-book-acim/