William of St-Thierry
William was born at Liège (in present-day Belgium) of a noble family between 1075 and 1080 (or 1085), and died at Signy in 1148. He probably studied at the cathedral school in Reims, though some have argued it was at Laon, prior to his profession as a Benedictine monk. He became a monk with his brother Simon at the monastery of St. Nicaise, also in Reims, sometime after 1111. From here both eventually became abbots of other Benedictine abbeys: Simon at St. Nicolas-aux-Bois, in the Diocese of Laon, and William at St. Thierry, on a hill overlooking Reims, in 1119.
In 1118 William met St. Bernard, abbot of the Cistercian monastery of Clairvaux, where they formed an intimate friendship that lasted for life. His greatest desire was to move to Clairvaux and profess as a Cistercian, but Bernard disapproved of the plan and imposed on him the responsibility of remaining in charge of the abbey at St. Thierry as a Benedictine. Their friendship, however, grew stronger while Bernard lay in the infirmary of Clairvaux convalescing after an illness in 1125.
William was instrumental in the first General Chapter meeting of the Benedictine abbots in the Diocese of Reims, in 1131, and it is possible that he hosted the chapter meeting at St. Thierry. After the second General Chapter of the Benedictines, held at Soissons in 1132, where many Cistercian reforms were adopted by the Benedictines, William submitted his Responsio abbatum ("Response of the Abbots") to Cardinal Matthew — papal legate in the diocese and critic of the abbots' reforms — successfully defending their reformation efforts. On account of long infirmities and a lifelong desire for a life of contemplation, William resigned his abbacy in 1135 and entered the newly established Cistercian abbey at Signy, also in the diocese of Reims. He did not venture to retire to Clairvaux lest his friend Bernard refuse to accept his abdication. There he divided his free time between prayer, study, and writing. According to a contemporary, his death occurred in 1148, about the time of the council held at Reims under Pope Eugenius. The necrology of Signy dates it 8 September, a few years prior to his good friend Bernard's death in 1153.
William wrote throughout all of his abbatial career as a Benedictine and his final years as a Cistercian monk. His earliest works reflect a monk seeking God continually and investigating the various and best ways of furthering the soul's ascent to God in spiritual union, William's ultimate goal. When read chronologically, one can discern the development and evolution of William's thought.
Toward the end of his career, having written extensively on spiritual life and especially on the moral interpretation of the biblical Song of Songs, William came across the writings of Peter Abelard, whose Trinitarian theology and especially Christology William found to be in error and dangerous to Christian faith. He wrote his own work against Abelard and alerted others about these concerns, urging St. Bernard to act. As a result, Abelard was condemned by the Council of Sens in 1140 or 1141. William wrote against what he saw as errors in the writings of William of Conches concerning trinitarian theology and also against Rupert of Deutz on sacramental theology.
Besides his letters to St. Bernard and others, William wrote several works, some of which he himself enumerates, though somewhat incorrectly. In total, there were twenty two works by William (twenty one extant), all written in Latin between c1121 and 1148.
In approximate chronological order, these include:
- De contemplando Deo (On Contemplating God) in 1121-1124. This is sometimes paired with De natura et dignitate amoris (below) under the title Liber solioquiorum sancti Bernardi.
- De natura et dignitate amoris (On the Nature and Dignity of Love) around the same time. This is sometimes called the Liber beati Bernardi de amore.
- Oratio domni Willelmi (Prayer of Dom. William) in 1120s.
- Epistola ad Domnum Rupertum (Letter to Rupert of Deutz).
- De sacramento altaris (On the Sacrament of the Altar) which is the earliest Cistercian text on sacramental theology and written in 1122-23.
- Prologus ad Domnum Bernardum abbatem Claravallis (Preface to Sac Alt to Bernard).
- Brevis commentatio in Canticum canticorum (Brief Comments on the Song of Songs) his first exposition of this biblical text in mid-1120s, written shortly after his time of convalescence with Bernard at Clairvaux.
- Commentarius in Canticum canticorum e scriptis S. Ambrosii (Commentary on the Song of Songs from the Writings of St. Ambrose) around 1128.
- Excerpta ex libris sancti Gregorii super Canticum canticorum (Excerpts from the Books of St. Gregory [the Great] over the Song of Songs) around the same year.
- Responsio abbatum (Response of the Abbots) from the General Chapter of Benedictine abbots in the diocese of Reims in 1132.
- Expositio super Epistolam ad Romanos (Exposition of the Letter to the Romans), written c1137.
- De natura corporis et animae (On the Nature of the Body and the Soul), written c1138.
- Expositio super Canticum canticorum (Exposition over the Song of Songs) his longer commentary on the Song of Songs, written c1138.
- Disputatio adversus Petrum Abelardum (Disputation against Peter Abelard) as a letter to Bernard in 1139.
- Epistola ad Gaufridum Carnotensem episcopum et Bernardum abbatem Clarae-vallensem (preface to Disputatio).
- Epistola de erroribus Guillelmi de Conchis (Letter on the Errors of William of Conches) also addressed to Bernard in 1141.
- Sententiae de fide (Thoughts on Faith) in 1142 (now lost).
- Speculum fidei (Mirror of Faith) around 1142-1144.
- Aenigma fidei (Enigma of Faith), written c1142-44.
- Epistola ad fratres de Monte-Dei (Letter to the Brothers of Mont-Dieu, more often called The Golden Epistle) in 1144-1145.
- Vita prima Bernardi (First Life of Bernard) in 1147 which was later added to by other authors after Bernard’s death in 1153.
Three of William's writings were widely read in the later Middle Ages. However, they were frequently attributed to Bernard of Clairvaux - a sign of their quality and also another reason for their continued popularity. Only in the early twentieth century did interest in William as a distinct writer begin to develop again and was his name correctly attached to all of his own writings.
William drew upon the existing and traditional monastic and theological authors of his day and significant authors of previous centuries, but not in a slavish way; rather he is creative and independent in his thought and exposition. His own commentaries show his remarkable insight while they also incorporate traditional authors such as Augustine of Hippo and Origen of Alexandria. Perhaps his most influential works are those dealing with the spiritual life of the contemplative monk. From his On Contemplating God to his Golden Epistle, one can see a progressive evolution of William's thought and a maturing of William's spiritual insight and experience, while also noticing an improved, more polished writing style and organization. Some scholars also argue that although William drew on texts and authors in the past, his creativity and usage of spiritual terminology was also influential on many other authors from the 12th century onward.
The Latin texts of most of William's writings are contained in J.-P. Migne's Patrologia Cursus Completus Series Latina (Patrologia Latina) volume 180, with other works also in volumes 184 and 185. All of his works are available in critical editions in the Corpus Christianorum Continuatio Medievalis series from Brepols in six volumes (86-89B). The bulk of William’s writings are available in English translation from Cistercian Publications  located in Kalamazoo along with the Institute for Cistercian Studies at Western Michigan University.
- JM Déchanet, William of Saint-Thierry: The man and his work, translated by R Strachan, Cistercian Studies series no. 10, (Spencer, MA, 1972)
- William Abbot of Saint Thierry: A Colloquium at the Abbey of Saint Thierry, translated from the French by Jerry Carfantan, Cistercian Fathers Series no. 94, (Kalamazoo, MI: Cistercian Publications, 1987)
- Bernard McGinn, The Growth of Mysticism, (1994), pp225–274
- Dégert, Antoine. "William of St-Thierry." The Catholic Encyclopedia. Vol. 15. New York: Robert Appleton Company, 1912. 6 Jun. 2013
- PL 184:365-80. A critical edition is Jacque Hourlier, Guillaume de Saint-Thierry: La contemplation de Dieu. L'Oraison de Dom Guillaume, (Sources Chretiennes 61). English translation is William of St Thierry, On contemplating God; Prayer; Meditations, translated by Sister Penelope, Cistercian Fathers Series no. 3, (Shannon: Irish University Press, 1971).
- PL 184:379-408. The English translation is William of St Thierry, The nature and dignity of love, translated by Thomas X Davis, edited with an introduction by David N Bell, Cistercian Fathers Series no. 30, (Kalamazoo, MI: Cistercian Publications, 1981)
- PL 180:341-366
- PL 184:407-435. English translation is William of St Thierry, A Brief Commentary on the Song of Songs, trans Denys Turner, in Denys Turner, Eros and Allegory: Medieval Exegesis of the Song of Songs, (Kalamazoo, MI: Cistercian Publications, 1995), 275-290.
- The Meditations of William of St. Thierry: Meditativae orationes. Translated from Latin by "A Religious of C.S.M.V." 1954. New York: Harper and Bros.
- PL 180:205-248. English translation is William of St Thierry, On contemplating God; Prayer; Meditations, translated by Sister Penelope, Cistercian Fathers Series no. 3, (Shannon: Irish University Press, 1971).
- PL 180:547-694. The critical edition in Latin is P Verdeyen, ed, Expositio super Epistolam ad Romanos CCCM 86, (Turnhout: Brepols, 1999). English translation is William of St Thierry, Exposition on the Epistle to the Romans, translated by John Baptist Hasbrouck, edited with an introduction by John D Anderson, Cistercian Fathers Series no. 27, (Kalamazoo, MI: Cistercian Publications, 1980).
- PL 180:695-726. English translation is: William of St Thierry, De natura corporis et animae, in B McGinn, ed, Three treatises on man: a Cistercian anthropology, Cistercian Fathers Series no. 24, (Kalamazoo, MI: Cistercian Publications, 1977).
- A critical edition is J-M Déchanet, Exposé sur le Cantique des Cantiques, (Sources Chretiennes 82). Also in PL 180: 475-546. English translation is William of St Thierry, Exposition on the Song of Songs, translated by Mother Columba Hart, edited with an introduction by JM Déchanet, Cistercian Fathers Series no. 6, (Shannon: Irish University Press, 1969).
- A critical edition is J-M Déchanet, Le miroir de la foi, (Sources Chretiennes 301). Also in PL 180:365-387. English translation is William of St Thierry, The Mirror of Faith, translated by Thomas X Davis, with an introduction by E. Rozanne Elder, Cistercian Fathers Series no. 15, (Kalamazoo, MI: Cistercian Publications, 1979).
- M-M Davy, Guillaume de Saint-Thierry: Deuz traités sur la foi, (Paris: Vrin, 1959). Also in PL 180:397-440. English translation is William of St Thierry, The enigma of faith, translated, with an introduction and notes, by John D Anderson, Cistercian Fathers Series no. 9, (Washington: Cistercian Publications, 1974).
- Critical edition by J-M Déchanet, Guillaume de Saint-Thierry. Lettre aux Frèrer du Mont-Dieu (Lettre d'or), Sources chretiennes 301, (1975). Also in PL 184:307-354. An older English translation is The golden epistle of Abbot William of St. Thierry to the Carthusians of Mont Dieu, now first translated into English by Walter Shewring and edited by Dom Justin McCann, (London: Sheed and Ward, 1930) [reprinted in 1980, with an introduction by Justin McCann, (London: Sheed and Ward, 1980)]. A more modern translation is printed in William of St Thierry, The golden epistle: a letter (of William of St. Thierry) to the brethren at Mont Dieu, translated by T Berkeley, edited with an introduction by JM Déchanet, Cistercian Fathers Series no. 12, (Kalamazoo, MI, 1976).
- These three works were the Epistola ad fratres de Monte Dei, sometimes called the Epistola aurea, the De natura et dignitate amoris, sometimes called the Liber beati Bernardi de amore, and the De contemplando Dei.
- "William of St-Thierry". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.
- Benedict XVI. "William Of St. Thierry : Cantor Of Love", General Audience, 2 December 2009
- William of St. Thierry: A Description of Clairvaux, c. 1143