Ousia
/ˈuː.si.ə/noun
A philosophical term meaning essence, substance, or the fundamental reality of a thing.
Did you know?Aristotle used ousia for what most fundamentally exists, while Christian theologians later used it to describe divine essence in the formula “one ousia, three hypostases.”
Etymological Timeline
Proto-Indo-European
PIE
*h₁es-
“To be or exist—the ancient root behind forms of “is” across Indo-European languages.”
Proto-Greek
Proto-Greek
*h₁ons-
“A participial form meaning “being” or “existing,” developing from the verb “to be.””
Classical Greek
Ancient Greek
οὖσα (ousa)
“Being; the feminine form of the present participle of εἰμί (eimi), “I am.””
4th Century BCE
Ancient Greek
οὐσία (ousía)
“Being, reality, substance, or essential nature; a major technical term in Aristotle’s philosophy.”
4th Century CE
Greek
οὐσία (ousía)
“Divine essence or substance in Christian theological debates, especially in contrast with hypostasis, “individual person” or “subsistence.””
Modern English
English
ousia
“A philosophical and theological loanword for essence, substance, or fundamental being.”