John Scotus Erigena (c. 810-c. 877) was an Irish theologian and philosopher. He served as a teacher in the royal academy of King Charles I (Charles the Bald) of France. He later taught at Laon, France. He translated the works of Pseudo-Dionysius the Areopagite (fifth century A.D.), Gregory of Nyssa (331-95), and Maximus the Confessor (c.580-662) from Greek into Latin. Erigena’s major works included: De Praedestinatione (On Predestination, 851) and De Divisione Naturae (On the Division of Nature, c. 862-66).

Erigena’s Periphyseon: On the Division of Nature is a philosophical treatise on how nature may be investigated as a unity of essence, creative power, and action. Erigena uses the term ‘nature’ to refer to the unity of all things. ‘Nature’ refers to all the creative and created principles of the universe. Erigena argues that ‘nature’ itself is not divisible, but that various species of nature may undergo differentiation. The division of nature is thus a differentiation into genera and species which may each have their own distinctive properties.

According to Erigena, there are four main species of nature: 1) that which creates and is not created, 2) that which creates and is created, 3) that which does not create and is created, and 4) that which neither creates nor is created. The first species of nature refers to Divine Nature (i.e. God). The second species of nature refers to the primordial causes or divine ideas which are the causes of all things. The third species of nature refers to the final effects of the primordial causes. The fourth species of nature refers to the final return of all things to unity in God.

Erigena argues that all things which are made by God have only God as their First Cause. There cannot be any other First Cause of the universe other than God. Everything ultimately has its being from God. God establishes the unity of all being, and is the First Principle of all things.

Erigena claims that the primordial causes are produced by God, who is the beginning of all things. The primordial causes are divine ideas, which guide the creation and development of the universe. According to Erigena, the primordial causes include: goodness, essence, life, wisdom, truth, intellect, reason, virtue, justice, salvation, magnitude, omnipotence, eternity, peace, and other principles which follow from the Wisdom of God. The primordial causes are created by God as primary principles of being for all things.

Erigena also claims that God created the world from formless matter, and that God created formless matter from nothingness. All formed and unformed things have the same First Cause. All material and non-material things depend on God for their being.

According to Erigena, God’s creative power and being are eternal. God is the Creator of an infinite nmber of things. An infinite number of things may be caused by God, and may have their being in God. God is infinitely perfect, and the being of all things in God is a perfect unity.

Erigena also claims that nothing can be the negation of God. If anything could be the negation of God, then it would have to be co-eternal with God. However, nothing could be co-eternal with God without also being co-essential with God. Thus, when God is referred to by names such as "Essence," "Goodness," "Truth," "Wisdom," "Justice," or "Eternity," these names are merely metaphorical and are not adequate to describe the infinite unity of God. If God were merely "Essence" or "Truth," then "Non-Essence" or "Falsehood" would be the negation of God. However, God is not merely essential to the being of all things, God is “more than essential” (i.e. "superessential"). God is not merely eternal, God is "more than eternal" (i.e. "supereternal"). Moreover, Divine Nature is not contradictory to Itself, and thus there can be no negation of God.

According to Erigena, there is nothing accidental to the being of God. The being of God is not contingent upon any set of conditions. God is "superessential," and transcends whatever is essential or accidental. Neither "Essence" nor "Accident" can adequately describe the being of God. However, God is the First Cause of whatever is essential or accidental. All essences and accidents have the First Cause of their being in God.

Erigena argues that God is not Being itself, but that God is the source of all Being. All Being proceeds from, and ultimately returns to, God. All Being is included in the infinite unity of God. God’s Being and Creating are One, and are the same undivided reality.

Erigena also argues that God, as the First Cause of all things, surpasses all understanding. The creative power of God cannot be comprehended by the intellect. Divine Nature cannot be defined by any name, and transcends any category of being. However, divine appearances or "theophanies" may, through the grace of God, be apprehended by the intellect. These "theophanies" may provide the intellect with images of eternal causes, and may provide insight into the eternal reasons for the being of things.

According to Erigena, the being of all things is a participation in the universal reality of God. Each genus or species of being participates in the reality of a genus or species higher than itself, and is participated in by a genus or species lower than itself. Each genus or species of being receives its reality by participating in a higher genus or species of being.

Erigena claims that each species of being is good to the extent that it participates in the goodness of a higher species of being. Thus, goodness is ultimately determined by whether a species of being participates in the goodness of God. Goodness may be demonstrated by a species of being which participates in the goodness of God. Evil may be demonstrated by a species of being which fails to participate in the goodness of God. The order of the universe has been established by Divine Providence. The being of all things ultimately depends on the Will of God. All things proceed from primordial causes which are produced by the Will of God.

According to Erigena, the process by which all things return to God may include stages in which various genera and species return to their primordial causes, and the primordial causes then return to God. All things, visible and invisible, material and spiritual, corporeal and incorporeal, must ultimately return to God to find the Cause of their being.

John the Scot (Joannes Scotus Eriugena). Periphyseon: On the Division of Nature. Translated by Myra L. Uhlfelder. Indianapolis: The Bobbs-Merrill Company, 1976.