ALCHER OF CLAIRVAUX—a representative of twelfth century mystical speculation, d. around 1180.
As a result of historical studies, Alcher is recognized as the author of the treatise De spiritu et anima (PL 40, 779—832), which was a response to Isaac of Stella'’s work Epistola ad quemdam familiarem suum de anima. Alcher’s work appeared anonymously, which led to many conjectures as to its true author. Some, including Albert the Great, attributed the work to St. Augustine. Others, including Thomas Aquinas, thought the work had a contemporary author. The work itself because of its erudite character had significant didactic value in the Middle Ages.
At present, the treatise is regarded as valuable from a historical point of view, since it contains many definitions of the soul and classifications of the soul’s powers, drawn from all the Latin sources accessible to the author (Lactantius, Macrobius, Augustine, Boethius, Bede, Alcuin, Hugh of St. Victor, and Isaac de Stella). Alcher also presented his own position. He regarded dynamism as the essential characteristic of the human being’s spiritual dimension. He made intense speculative investigations of this dynamism. As a result, he presented precise definitions concerning man’s hylemorphic structure. With regard to the specific status of the human soul as an imitation of divine properties, he demonstrated that the soul is the place where we experience not only God’s existence, but also his nature (his boundlessness and fullness). According to Alcher, rationality sets man apart from the other animals, and mortality sets him apart from other spiritual beings.
M. de Wulf, Histoire de la philosophie médiévale, Lv 1900, 19346, I 226–227; M. D. Chenu, La première diffusion du thomisme à Oxford, AHDLMA 3 (1928), 185–200; P. Michaud-Quantin, La classification des puissances de l’âme au XIIe siècle, Revue du Moyen Ages latin 5 (1949), 20–34; S. Swieżawski, Homo platonicus w wiekach średnich [Homo platonicus in the Middle Ages], RF 2–3 (1949–1950), 264–271; Gilson HFS 155, 577, 602, 629; J. Lewicki, Filozoficzna nauka Alchera z Clairvaux o Bogu w świetle jej źródeł [Alcher of Clairvaux’s philosophical doctrine of God in the light of his sources], RF 5 (1955–1957) 3, 79–94; E. Manning, Dictionnaire des auteurs cisterciens, Rocheford 1975, 28–29; H. Möhle, LThK 1 (19933) 349–350.