This study attempts to map the meanings and roles that the concept non aliud newly created by Nicholas of Cusa has in his works. It serves in first place as an aenigma, another name for God that guides our thinking to an understanding of the way in which the first principle defines itself as well as other things.
In its basic meaning the "definition" describes on the one hand the way by which a thing originates in its being, and on the other the process by which our knowledge proceeds. In both cases identity, which stands at its ground and is thus the most fundamental meaning of the concept "not other", plays a major role.
The study has further sought for concordances and differences between non aliud and another similarly limitary concept of Cusanus, possest. Their most important difference lies in that non aliud captures above all the operation of God outside himself as the source of the definition and existence of things which originate in and are formed by the world.
In contrast, possest lays emphasis on the absolute difference and transcendence of the first beginning in relation to the creation.