ILLUMINATION

Literally, the action of illuminating or the condition of being illuminated; in philosophy and theology, a special divine influence aiding man in obtaining certain, necessary, and universal knowledge. The latter notion is discussed here in its sources, in Augustinian thought, and in some later applications.

Sources. In ancient and medieval thought, light was considered ontologically as both a physical and a spiritual substance. On this basis a metaphysics of light developed; its offspring was a noetics of light called the theory of illumination. The premises for such a theory were found in the monistic system of emanation of plotinus, who taught that the world soul emanates from the One via the Nous. This world soul sends its rays and mirrors itself in bodies as the fourth hypostasis. Such illumination is a two-way process, however, for the rays reflected from the bodies return to the soul, to the Nous, to the One in a mystic ascent, and to a final reunion in which being and cognition are identical.

Plotinus's teaching was transmitted to the later Middle Ages through neoplatonism. The Arabs generally adopted the theory, but brought into it Aristotelian notions. In this amalgam the intellectus agens of Aristotle was no longer an individual human possession, but one for the entire human species, identified with the tenth Cosmic Intelligence.

Augustine's Theory. St. augustine utilized the doctrine of divine light in St. John's gospel to develop a theory of knowledge. Convinced of man's personal nature, Augustine was safe from Plotinus's monopsychism of the fourth hypostasis; human knowledge, for him, does not originate in an identity of man with the intelligible world, but rather in an encounter with this world without loss of personal uniqueness.

Augustine's theory of knowledge distinguishes an object, a subject, and a medium of knowledge. These three components are proportioned to, and cooperate with, one another in the noetic process. The objects are the material and immaterial things known. The knowledge of sensible things, as well as the knowledge of spiritual objects, can be obtained only under the influence of divine illumination. The senses draw the soul's attention to what is happening outside the soul, and their reports are judged in the divine light by the intellect. The true objects of knowledge are the eternal reasons, which rank higher than the created intellect, being contained in the divine intelligence. They constitute the intelligible world of truths hierarchically ordered to, and culminating in, eternal truth. By participation in these rationes aeternae a thing is what it is. Therefore, the human intellect can find these reasons in all things. It depends on these truths for its judgment and certainty.

The subject in this process of knowledge is the knowing intellect, man's soul. The soul is not the very nature of truth. Although "all men are lamps" (In Ioann. 23.3), they remain in darkness unless they are illuminated by the true Light. And while man, by virtue of his intellectual nature, corresponds to the intelligible truths in the divine light, the whole man (intellect and will) is required in knowing by divine illumination. The medium through which object and subject unite in knowledge is the divine light. God alone is the true light. It is He who enlightens and makes intelligible.

Later Developments. In the 13th century, because of contact with Arabian theories of knowledge and with translations of Aristotle's works (especially William of Moerbeke's), Augustine's theory of illumination—until then the only theory of knowledge for Christian thinkers —was gradually supplanted by the theory of abstrac tion. St. bonaventure, however, while using the Aristotelian theory to explain sense knowledge, invoked divine illumination—i.e., direct action of the eternal reasons upon the intellect—as necessary for making infallible judgments.

St. thomas aquinas replaced divine illumination by the agent intellect, a power created and given by God to man for the purpose of knowing and judging. Thus, for him, the illuminating factor is given in man's nature. In a "conversion to the phantasm" the agent intellect makes the noetic object appear in the human consciousness. But that which is seen (illuminated) is not the thing as such (a form in matter) but a form abstracted from matter, the universal abstracted from the particular, the intelligible species abstracted from the phantasm. "Therefore, we must say that our intellect understands material things by abstracting from the phantasms; and through material things thus considered we acquire some knowledge of immaterial things" (Summa theologiae 1a, 85.1).

A return to the illumination theory occurred in the 17th century with Nicolas malebranche. He says in his answer to the first objection to the tenth of his Éclaircissements sur les six livres de la Recherche de la Verité (Paris 1678, 3:124): "Naturally, the mind is capable of movement in its ideas…. But it does not move itself, it does not enlighten itself; it is God who effects everything (qui fait tout ) in the minds as well as in the bodies." This ontological premise led Malebranche directly to oc casionalism, which holds that God establishes occasional causes in order to produce definite effects—such as the individual man's recognizing and knowing the here-and-now presented object.

A 20th-century controversy arose over interpretations of St. Augustine's illumination theory, with various scholars favoring the ontologistic, the historical, the concordant, and the existential schools respectively. Although many issues of Augustinian epistemology were thus clarified, there remained a shadow of opaqueness, for Augustine himself never completely elucidated the function of the divine light in the noetic realm.

See Also: illuminism; knowledge, theories of

Bibliography: f. c. copleston, History of Philosophy (Westminster, Md. 1946) v. 2, 4. s. vanni-rovighi, Enciclopedia filosofica 2:1237–41. j. auer, Lexikon für Theologie und Kirche, ed. j. hofer and k. rahner, 10 v. (2d new ed. Freiburg 1957–65) 5:624–625. É. h. gilson and t. d. langan, Modern Philosophy: Descartes to Kant (New York 1963). a. a. maurer, Medieval Philosophy (New York 1962). k. rahner, Geist in Welt (2d ed. Munich 1957). j. ratzinger, "Licht und Erleuchtung: Erwägungen zur Stellung und Entwicklung des Themas in der abendländischen Geistesgeschichte," Studium generale 13 (1960) 368–378. c. e. schÜtzinger, The German Controversy on St. Augustine's Illumination Theory (New York 1960).

[c. e. schÜtzinger]