Sunyata

Sanskrit; sunnata (Pali); literally, "emptiness"; a central Buddhist idea which states that all phenomena are "empty," i.e. dependent and conditioned on other phenomena and therefore without essence; Theravadins applied this idea to the individual to assert the non-existence of a soul; Mahayanists later expanded on this idea and declared that all existence is empty; emptiness became the focus of the Madhyamika school of the Mahayana Buddhism; the notion of emptiness has often led to Buddhism being wrongfully confused with a nihilistic outlook.

literally, "to strive after the void," without which nothing would have any value or function. A cup that is not void cannot hold liquid. A room that is not void cannot house people. A person (atman) who is not void (ie., pure) cannot possess the divine state (Atman).