The use of Substantia in Hilary of Poitiers' De Trinitate and De Synodis: consistency or confusion?

Abstract

Summary: I. Introduction. II. Substantia in De synodis and De Trinitate – an Overview. III. Substantia in De synodis. IV. Substantia in De Trinitate. V. Conclusions.

Hilary of Poitiers is renowned for his tireless defence of the Nicene faith during the great theological crisis of the fourth century. In expounding his Trinitarian theology, Hilary utilized the term substantia to refer to the ‘oneness’ within the Trinity. However, occasionally he also used substantia to refer to the divine persons. In recent times, Hilary has been criticized for employing this term in an inconsistent manner. This article shows that there are valid reasons for Hilary’s apparent inconsistent use of this significant term.