Isaac of StellaIsaac of Stella (c. 1100, in England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 – c. 1169, Étoile, Poitiers

Poitiers

Poitiers is a city on the Clain river in west central France. It is a commune and the capital of the Vienne department and of the Poitou-Charentes region. The centre is picturesque and its streets are interesting for predominant remains of historical architecture, especially from the Romanesque...

, Poitou

Poitou

Poitou was a province of west-central France whose capital city was Poitiers.The region of Poitou was called Thifalia in the sixth century....

, France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

) was a monk

Monk

A monk is a person who practices religious asceticism, living either alone or with any number of monks, while always maintaining some degree of physical separation from those not sharing the same purpose...

, theologian and philosopher. He joined the Order of Cistercians, during the reforms of Saint Bernard of Clairvaux

Bernard of Clairvaux

Bernard of Clairvaux, O.Cist was a French abbot and the primary builder of the reforming Cistercian order.After the death of his mother, Bernard sought admission into the Cistercian order. Three years later, he was sent to found a new abbey at an isolated clearing in a glen known as the Val...

.

Isaac's works make use of logical argumenation, influenced by Augustine of Hippo

Augustine of Hippo

Augustine of Hippo , also known as Augustine, St. Augustine, St. Austin, St. Augoustinos, Blessed Augustine, or St. Augustine the Blessed, was Bishop of Hippo Regius . He was a Latin-speaking philosopher and theologian who lived in the Roman Africa Province...

's neoplatonism

Neoplatonism

Neoplatonism , is the modern term for a school of religious and mystical philosophy that took shape in the 3rd century AD, based on the teachings of Plato and earlier Platonists, with its earliest contributor believed to be Plotinus, and his teacher Ammonius Saccas...

. His main work was Letter to Alcher on the Soul (1162), addressed to Alcher of Clairvaux

Alcher of Clairvaux

Alcher of Clairvaux was a twelfth-century Cistercian monk of Clairvaux Abbey. He was once thought to be the author of two works, now attributed by many scholars to an anonymous pseudo-Augustine of the same period....

, which combined Aristotelian

Aristotelianism

Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...

and Neoplatonic theories about psychology with Christian mysticism.