WorkBoethius

A Treatise Against Eutyches and Nestorius

Two opposite heresies, one splitting Christ and one fusing him: Boethius answers both by fixing what the words *nature* and *person* are allowed to mean.

by Boethius33 passages held

English, a translation held here, and your language

Original title: Contra Eutychen et Nestorium
First published: 512(aged 35)
Original language: Latin

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Overview

A letter reached Rome around 513 in which Eastern bishops proposed a formula to heal a Christological quarrel, and Boethius, sitting in on the discussion, went home dissatisfied and wrote this short tractate to settle the terms properly. His targets are two heresies pulling in opposite directions: Nestorius, who so divided Christ that he made him two persons, and Eutyches, who so merged him that he left only one nature. Boethius treats the dispute as a problem in logic — what exactly the words nature and person can mean — and works toward definitions precise enough that both errors become sayable, and therefore refusable. His definition of a person as an individual substance of a rational kind outlived the controversy that produced it and passed into the standard vocabulary of medieval theology and philosophy. It is a technical piece, arguing that the doctrine holds only if the words are held steady.

Key concepts

What is Boethius's definition of a person?

An individual substance of a rational nature, naturae rationabilis individua substantia. Each word does work: substance, so a person is a real subsisting thing, not a quality; individual, so it is this one and not a shared kind; and of a rational nature, so it is the sort of thing capable of reason. The formula outlived the quarrel that produced it and became the standard definition of person in medieval philosophy and theology.

What did Nestorius and Eutyches each teach?

They erred in opposite directions on how Christ can be both God and man. Nestorius so divided the two that he made Christ effectively two persons joined together. Eutyches so fused them that Christ was left with only one nature, the human absorbed into the divine. Boethius sets his definitions of nature and person to make each error precisely stateable, and therefore refutable, steering between the two.

How does Boethius distinguish nature from person?

Nature answers what a thing is, the kind it belongs to, and can be shared by many; person picks out the individual that bears a nature. Christ, on the orthodox view Boethius defends, has two natures, divine and human, in one person. Keeping the two terms apart is exactly what lets him affirm the union without either splitting Christ into two or collapsing his two natures into one.

Why does Boethius treat theology as a problem in logic?

Because he holds that the doctrine stands or falls with the precision of its terms. If nature and person are used loosely, both heresies can hide in the vagueness; if they are defined exactly, each becomes sayable and so can be refused. The tractate is a technical piece arguing that a mystery of faith can still be examined with the tools of Aristotelian logic, which Boethius spent his life translating.

Themes of the book

What this book returns to, gathered into themes and ordered by how much of the text each one occupies.

Fixing what nature and person mean

Can a doctrine be defended without first pinning down its words? Boethius treats a Christological quarrel as a problem in logic: settle what nature and person can mean, and the errors become sayable and so refusable.

Two heresies pull in opposite directions. Nestorius so divides Christ that he makes two persons; Eutyches so merges him that only one nature is left. Boethius argues the dispute holds together only if the terms are held steady, so he works toward definitions precise enough that both errors can be stated exactly and rejected. His account of person, an individual substance of a rational nature, outlived the controversy and became standard vocabulary in medieval thought. Nature he ties to what a thing is; person, to the individual that bears it. In theology as in logic, he shows, an argument is only as firm as the words it turns on.

ontology
personhood
nature
substance
definition
metaphysics
unity
christology
incarnation
human nature
matter

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Within this work

passages held: 33
distinct concepts: 54
by passages held, corpus-wide: #253

What this book thinks together

Every arc around the wheel is one concept in this book. A ribbon joins two the text reaches for together, and its width is how many of its passages hold both. Strongest: metaphysics with ontology.

Concept co-occurrence, strongest first 8 concepts, joined by 17 pairings. 54 shared passages in all. 12 weaker pairings reach beyond these concepts and are not drawn.
Concept	Paired concept	Shared passages
metaphysics	ontology	8
logic	nature	4
logic	theology	4
metaphysics	nature	4
ontology	personhood	4
personhood	theology	4
logic	personhood	3
metaphysics	personhood	3
metaphysics	theology	3
ontology	substance	3
logic	metaphysics	2
metaphysics	substance	2
nature	ontology	2
nature	personhood	2
ontology	semantics	2
personhood	substance	2
semantics	theology	2

Works held

The author's work in order, this book marked in place. Your-language title first, the original beneath it where the two differ; side chips show which full texts are held.

512 A Treatise Against Eutyches and Nestorius (Contra Eutychen et Nestorium) you are here LAEN
520 How Substances Can Be Good In Virtue of Their Existence Without Being Absolute Goods (Quomodo substantiae in eo quod sint bonae sint cum non sint substantialia bona)
Argued from stated axioms rather than scripture, this is the most purely philosophical of Boethius's theological tractates, and important enough that Aquinas later wrote a commentary on it.
LAEN
520 On the Catholic Faith (De Fide Catholica)
Doubted for centuries and restored to the set on the strength of its manuscript transmission and style, this is a plain confession of faith rather than one of the logical tractates.
LAEN
520 The Trinity (De Trinitate)
Prompted by a sixth-century controversy over the Trinity, it brings the Aristotelian logic Boethius spent his life translating to bear on the doctrine, and drew close attention from later medieval schools.
LAEN
524 The Consolation of Philosophy (De Consolatione Philosophiae)
Written in prison as Boethius awaited execution, this dialogue of alternating prose and verse became the most widely read book of the Latin Middle Ages after the Bible, translated by kings and poets for a thousand years.
LAEN

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