Letter 15: Leo, bishop, to Turribius, bishop, greeting. Your laudable zeal for the truth of the Catholic Faith, and the painstaking devotion you expend in the exercise of your pastoral office upon the Lord's flock is proved by your letter, brother, which your deacon has handed to us, in which you have taken care to bring to our knowledge the nature of the ...

Pope Leo the GreatTurribius|c. 442 AD|leo great
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Barbarian peoples/invasions; Theological controversy; Imperial politics

Leo to Turribius, Bishop of Astorga, concerning the errors of the Priscillianists.

I. Introduction: Leo has received Turribius's report on heresy in Spain

We have read with deep concern, dear brother, the letter in which your loving zeal for the Catholic faith brought to our attention the errors that have taken root among you through the influence of the Priscillianist heresy. These errors, born of the old Manichaean impiety and clothed in new disguises, threaten the integrity of the faith in your provinces. The matter demands our urgent attention, for unless these poisonous doctrines are exposed and condemned with full clarity, they will spread their corruption still further.

We commend your diligence in reporting these things to us, for this is how the body of Christ functions: the members must communicate with the head, so that remedies may be applied where the disease has been found. We therefore address ourselves to each of the errors you have identified, so that every bishop in your province may know precisely what must be condemned and why.

II. On the Trinity: the Priscillianist errors are condemned

The Priscillianists, following the Sabellian heresy, confuse the Persons of the Holy Trinity so as to claim that the Father, the Son, and the Holy Spirit are one and the same Person under different names, rather than a Trinity of distinct Persons in one divine substance. This is a grave error. The Catholic faith confesses one God in Trinity and Trinity in Unity: Father, Son, and Holy Spirit -- three Persons, but one essence, one majesty, one power. The Father is not the Son, nor is the Son the Holy Spirit, yet the Father and the Son and the Holy Spirit are one God. Whoever confuses the Persons or divides the substance has departed from the faith.

III. On the origin of souls

They teach that human souls are a portion of the divine substance, thereby making the Creator and the creature one and the same. This blasphemy must be utterly rejected. The soul is God's creation, not a fragment of His being. To say that the soul is of the same substance as God is to subject the divine nature to change, suffering, and degradation -- all of which are impossible for the unchangeable God. The Catholic faith holds that God created the soul out of nothing, endowing it with free will, and that whatever goodness the soul possesses comes from its Creator's gift, not from identity of substance.

IV. On the assumption of flesh by the Son of God

The Priscillianists deny that the Son of God assumed true human flesh in the womb of the Virgin Mary. Some of them say He had only an apparent body; others say His body was of a celestial or spiritual substance, not real human flesh taken from the Virgin. Against these fictions we affirm: the Son of God took true flesh from the Virgin Mary through the operation of the Holy Spirit. He was truly born, truly suffered, truly died, and truly rose again. His body was real, not phantasmal. His human nature was complete -- possessing a true body and a rational soul -- and was united to His divine nature in one Person, without confusion, without conversion, without division, without separation. Whoever denies the reality of the Incarnation makes void the entire mystery of our redemption.

V. On the authority of the Old Testament

These heretics reject the patriarchs and prophets of the Old Testament, claiming that the God who spoke through them is a different and inferior deity. This Manichaean blasphemy we utterly condemn. The God of the Old Testament and the God of the New are one and the same. The Law and the Prophets prepared the way for the Gospel. Christ Himself testified: "Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill" (Matthew 5:17).

VI. On the devil and the origin of evil

They assert that the devil was never a good angel, but emerged from chaos and darkness, having no creator but being himself the principle of evil. This contradicts the clear teaching of Scripture, which declares that all things were made by God and that God saw all He had made and pronounced it very good (Genesis 1:31). The devil fell from his original goodness by his own free will, not by the defect of his nature. Evil is not a substance but a corruption of the good.

VII. On marriage and procreation

The Priscillianists condemn marriage and the begetting of children, holding that all flesh is the work of the devil. The Catholic faith declares that God instituted marriage from the beginning and blessed it, saying: "Be fruitful and multiply" (Genesis 1:28). The body is not evil; it is God's creation. The resurrection of the body confirms its dignity. Those who condemn what God has created speak with the voice of demons, not of truth, as the Apostle warns: "In later times some will depart from the faith, paying attention to deceitful spirits and doctrines of demons, forbidding marriage and commanding abstinence from foods that God created to be received with thanksgiving" (1 Timothy 4:1-3).

VIII. On astrology and fatalism

They claim that human souls and bodies are bound to the influence of the stars, and that our lives are governed by the movements of the heavens. This fatalism destroys free will and makes God the author of sin. The Catholic faith affirms that while God governs all things by His providence, He has endowed humanity with free will, and each person bears responsibility for his own choices. No star compels a man to sin, and no celestial configuration excuses wickedness.

IX. On the canonical Scriptures

The Priscillianists employ a vast number of apocryphal writings, which they place on the same level as the canonical Scriptures or even above them. We decree that only those books are to be received which the authority of the Church has approved. The apocryphal writings employed by these heretics are to be not merely rejected but condemned and burned, for they contain false teachings concealed under the names of the Apostles. As the Apostle says: "Test everything; hold fast what is good. Abstain from every form of evil" (1 Thessalonians 5:21-22).

X. Conclusion: a synod must be convened

We urge you, brother, to convene a council of the bishops of your province -- and of neighboring provinces as well, if it can be arranged -- so that these errors may be formally investigated and condemned. Let every priest make a clear and public confession of faith. Let those who are found to be infected with these errors be given the opportunity to repent; but let those who persist in them be expelled from the communion of the Church. For it is better that a few diseased members be cut off than that the whole body be corrupted.

We have committed this letter to our brother Pervinquus, who will convey it to you. See that it reaches all the bishops of your province.

Dated in the consulship of the illustrious Maximus and Paterius (AD 443).

Modern English rendering for readability. See the 19th-century translation or original Latin/Greek for scholarly use.

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