Ousia

Ousia (ˈuːziə,_ˈuːsiə,_ˈuːʒə,_ˈuːʃə; οὐσία) is a philosophical and theological term, originally used in ancient Greek philosophy, then later in Christian theology. It was used by various ancient Greek philosophers, like Plato and Aristotle, as a primary designation for philosophical concepts of essence or substance. In contemporary philosophy, it is analogous to English concepts of being and ontic. In Christian theology, the concept of θεία ουσία (divine essence) is one of the most important doctrinal concepts, central to the development of trinitarian doctrine. The Ancient Greek term θεία ουσία (; divine essence) was translated in Latin as essentia or substantia, and hence in English as essence or substance. The term οὐσία is an Ancient Greek noun, formed on the feminine present participle of the verb εἰμί, , meaning "to be, I am", so similar grammatically to the English noun "being". There was no equivalent grammatical formation in Latin, and it was translated as essentia or substantia. Cicero coined essentia and the philosopher Seneca and rhetorician Quintilian used it as equivalent for οὐσία, while Apuleius rendered οὐσία both as essentia or substantia. In order to designate οὐσία, early Christian theologian Tertullian favored the use of substantia over essentia, while Augustine of Hippo and Boethius took the opposite stance, preferring the use of essentia as designation for οὐσία. Some of the most prominent Latin authors, like Hilary of Poitiers, noted that those variants were often being used with different meanings. Some modern authors also suggest that the Ancient Greek term οὐσία is properly translated as essentia (essence), while substantia has a wider spectrum of meanings. From οὐσία (essence), philosophical and theological term οὐσιότης (essentiality) was also derived. It was used by Platonists, like Alcinous, as designation for one of the basic properties of divinity or godhead. Aristotle defined πρῶται οὐσίαι (; primary essences) in the Categories as that which is neither said of nor in any subject, e.