光的意象在西方古典時期被廣泛運用來描述神的神性。卡帕多西亞教父尼撒的格列高利在其教義著作中常運用這一意象。然而，學界並未給予格列高利這一意象應有的關注。本文將探究格列高利在其三一論中如何運用光的意象來辯護聖子和聖父的同等神性問題。我們將集中討論光的意象在其教義著作中相互聯繫的三個方面：光作為表示基督神性的基督名稱、「出自光明的光明」作為強調聖子和聖父同等地位的尼西亞信條、用以闡釋聖子如何既和聖父同等又生於聖父的光的意象。我們的研究表明格列高利在教義著作中用光的意象將三位一體的關係展現為聖父和聖子共同參與的內在的和外在的互動活動。這樣的互動活動提供了理解神如何將自身同時展現為既是一又是三的一種有效的方式。

The image of sun and light is widely used to address the divinity in classical antiquity. The Cappadocian Father, Gregory of Nyssa, uses it frequently in his doctrinal works on Trinitarian theology. Unfortunately, this imagery has not received much studies in either historical studies on light imagery in classical antiquity or theoretical studies of Gregory’s theology. This article investigates how Gregory uses the light imagery to defend the equal eternity of the Son and the Father in his Trinitarian theology. We focus on the three interrelated aspects of the light imagery in his doctrinal works: light as Christological title which signifies Christ’s divinity, the Nicene formula “Light from Light” as highlighting the equal eternity of the Son with the Father, and the light imagery as a way to illustrate how the Son being both equal with and generated from the Father. Our investigation shows that the light imagery in Gregory’s doctrinal works translates the mystical Trinitarian relation into internal and external dynamic activities that both the Father and the Son engage in together, and the dynamics between them gives a way to understand how God manifests himself as one and three simultaneously.