Isaac of Stella

Isaac of Stella, also referred to as Isaac de l'Etoile, (c. 1100, in England – c. 1170s, Étoile, Archigny, France) was a monk, theologian and philosopher.

About 1140 he abandoned the schools and joined the Order of Cistercians, during the reforms of Saint Bernard of Clairvaux, probably at Pontigny. In 1147 he became abbot of the small monastery of Stella, outside Poitiers. At some time in his later career, most likely in 1167, he was exiled to a remote monastery on the Atlantic Isle of Re, probably because of his support for Archbishop Thomas Becket. He later returned to Stella. It is known he lived at Stella on into the 1170s because in one of his sermons he refers to meeting 'Saint' Bernard - and Bernard was only canonised in 1174.

Isaac's most popular work was an allegorical commentary on the canon of the Mass in the form of a letter to John of Canterbury, bishop of Poitiers. His 55 surviving sermons (and three sermon fragments), as well as his Letter to Alcher on the Soul, constitute his real theological contribution. The Letter (1962) was addressed to Alcher of Clairvaux, and combined Aristotelian and Neoplatonic theories about psychology with Christian mysticism. It exercised a significant role in later mystical speculation due to the incorporation of large sections of Isaac's work in the anthropological compendium known as De spiritu et anima (The Spirit and the Soul), which circulated under the name of Augustine and was widely used in the 13th century.

Isaac's works make use of logical argumentation, influenced by Augustine of Hippo's Neoplatonism.