Meaning of ‘Hypostasis’ – Encyclopedia of Ancient Christianity

“As a technical term, hypostasis is found first in the Greek natural sciences, meaning sediment in a liquid. Behind this is a twofold idea, solidification and visibility, which appears in every use of the word, with one aspect or the other predominating. Thus in the Greek Bible, hypostasis refers in particular to true reality (see Heb 1:3; 3:14; 11:1); the Stoic tradition sees in the hypostasis the last individualization of the primordial essence; it is likewise present in Neoplatonic tradition, i.e., from Porphyry on–not yet in Plotinus–though on an entirely spiritual level and with a nuance of progression. The same is true for the technical use of the term which the Christian authors employ–always confronting the three traditions mentioned–in trinitarian theology and then in christology. Taken up by the Origenian tradition, just as ousia in order to emphasize the three divine realities in an anti-Sabellian way, hypostasis found a more ample consensus in the Synod of Alexandria (362). The Cappadocians, who contrasted the three hypostases with the one nature, the formula sanctioned also by the Council of Constantinople (381), nevertheless explained the term by emphasizing its characteristic aspect, individuality. Based on the new interpretation of the concept of hypostasis, Basil, and later Cyril of Alexandria, compared the trinitarian usage with the Porphyrian doctrine of the three hypostases. In the same period, Apollinaris of Laodicea introduced the term in christology, emphasizing by it the one reality of Christ. Hypostasis with this meaning became prominent through Cyril of Alexandria. Clearly distinguished from “nature,” it entered also into the faith of Chalcedon (DS 302). Nevertheless, in later discussions, in which there was an awareness that both of the natures in Christ, as Nestorius had intended, must be hypostatic, i.e., individual, the Byzantine authors emphasized in the hypostasis the aspect of subsistence, as well as that of characterizing property, so as to be able to use the term justly in both trinitarian theology and christology” (B. Studer, Encyclopedia of Ancient Christianity, vol 2, p. 308).