Abstract

This dissertation examines St. Thomas Aquinas's teaching on the way that divine illumination is exercised on the human intellect. God's illuminative causality is an instance of His creative causality, and Aquinas's mature teaching on the divine illuminative influence is found in the Summa theologiae's treatise on creation . Aquinas holds that God is efficient, exemplar, and directive cause of the intellect. ;Chapter 1 discusses Aquinas's use of the term "light" itself. For Aquinas, "light" is predicated of spiritual being properly, and not just metaphorically. ;Chapter 2 examines the doctrines of illumination of Robert Grosseteste and Bonaventure. Grosseteste's metaphysics of light, and his teaching on the nature of the intellect are examined. Bonaventure articulates his doctrine of divine illumination in the Itinerarium and the disputed questions De scientia Christi. For Bonaventure, the presence of the divine light explains both the certitude of human knowledge and the intimacy of God to the mind. ;Chapter 3 examines Aquinas's teaching. As efficient cause of the light of the human intellect, God communicates an inherent, participated light-form which is the source of the intellect's proper activity. As exemplar cause, God signs or stamps the light of the intellect with a likeness of the divine light and of the eternal reasons. Through this stamp, man knows in the eternal reasons. ;Chapter 4 examines God's moving and directing of the light of the intellect to action. God both impresses the inclination of the participated light to action, and illuminates the participated light. Impressio is a continuous motion from God in the creature, by which God gives to the creature the inclination that follows upon its form. Impressio is a motion that directs. Illuminatio moves and directs the intellect to its proper operation, which is the knowledge of truth. ;Chapter 5 shows that God's moving of the intellectual light accounts in part for the content of the first speculative and practical principles, which are contained in the habits of intellectus and synderesis. The habits themselves arise in us through the intrinsic causality exercised by the human intellectual light. Because this light is the locus of a divine impress, however, first principles are the bearers of a divine extrinsic measure. Thus, Aquinas retains one of Augustine's central insights: through divine illumination the mind knows according to a divine measure