non-substantiality ［空］ ( shūnya or shūnyatā; kū): A fundamental Buddhist concept, also translated as emptiness, void, latency, or relativity. The Sanskrit shūnya or shūnyatā means emptiness. Shūnya also means “empty” and “empty of.” It is the concept that things and phenomena have no fixed or independent nature or existence of their own. Non-substantiality is neither negative nor world-negating but teaches the importance of perceiving the true nature of phenomena, which are on the surface transient. The Wisdom sutras developed the Mahayana concept of non-substantiality and Nāgārjuna (c. 150–250) systematized it based on them. This concept originated in connection to those of dependent origination and of the nonexistence of self-nature. Dependent origination means that, because phenomena arise only by virtue of their relationship with other phenomena, they have no distinct nature or existence of their own. Nonexistence of self-nature means that there is no independent entity that exists alone, apart from other phenomena. The common message is that the true nature of all phenomena is non-substantiality, and that it cannot be defined in terms of the concepts of existence and nonexistence. Nāgārjuna explained it as the Middle Way, a perspective that regards the categories of existence and nonexistence as extremes, and aims to transcend them. The practical purpose behind the teaching of non-substantiality lies in eliminating attachments to transient phenomena and to the ego, or the perception of self as an independent and fixed identity.