ALCHERO of CHÂTILLON (Alcherus; less accurately Alcérino or Alchiero). - A Cistercian monk of Clairvaux, where he was a disciple of St Bernard. Little is known of his life: he seems to have died around 1180. To satisfy a doubt of his concerning the intimate and mysterious union of the soul with the body, Isaac of Stella (q.v.) addressed to him the epistle or treatise *De anima* (PL 194, 1875-90). Peter of Celle (q.v.) sent him the book *De conscientia* (PL 202, 1883-98) in reply to his question “quid sit bona conscientia” (PL 202, 1089). Only from these writings can elements be drawn that define the spiritual profile of A.: a studious and devoted lover of “physica,” that is, medicine and the natural sciences (cf. PL 194, 1882), and a pious and diligent compiler (cf. PL 202, 1089). On account of these characteristics, certain short works have been attributed to him, previously circulated under the names of St Augustine, Hugh of Saint-Victor, and others.
I. Chief among these is the *De spiritu et anima* (PL 40, 779-832): a psychological treatise appended to the works of St Augustine, which summarizes the entire preceding tradition, drawing on Augustine, Gennadius, Cassiodorus, Bede, Alcuin, Boethius, Hugh of Saint-Victor, Isaac of Stella, and others. Composed around 1160 and circulated anonymously, it soon came to be attributed to St Augustine and, a century later—especially on the question of the simplicity of the soul—became a veritable battleground in the theological disputes between representatives of the Platonic-Augustinian school and those of the Aristotelian school. The former attributed it to St Augustine and defended its authenticity, citing it as an “auctoritas”; the latter attributed it instead to a Cistercian monk, whom some identified as a certain William, “qui multa falsa dixit”: thus Albert the Great (In I Sent., d. 8, a. 25, ad 2), who in his *Summa Theologiae* cites the short work some thirty times. Thomas Aquinas also cites it frequently in his various works for polemical reasons; yet while in his Commentary on the Sentences he places it under Augustine’s name, in the *Summa Theologiae* he uses the anonymous formula: “Sicut dicitur in libro de Spiritu et Anima.” Notable is what he states in the *IV Sent.*: “Ad primum dicendum, quod liber ille negatur a quibusdam esse Augustini: dicitur enim fuisse cuiusdam cistercensis qui eum ex dictis Augustini compilavit et quaedam de suo addidit” (d. 44, q. 3, a. 3, col. II, ad 1). Hence, although in some editions of the works of St Thomas, such as that of Frette (published by L. Vièvès of Paris), the name of A. has entered the text, this does not accord with the manuscripts, which instead of Alcherus have Augustinus (cf. In IV Sent., d. 44, q. 1, a. 2, quaestiuncula 3, Sed contra, in the cited edition of Frette, XI, Paris 1874, p. 30).
As for the use of this writing in controversial matters, the Angelic Doctor concludes: “Nec multum curandum de his quae in eo dicuntur” (*De Anima*, a. 12, ad 1), since “liber ille auctoritatem non habet: unde quod ibi scriptum est, eadem facilitate contemnitur, qua dicitur” (*Sum. Theol.*, I, q. 77, a. 8, ad 1).
Nevertheless, this short work was cherished by St Bonaventure, who cites it under the name of St Augustine some fifty times (cf. *Opera omnia*, X, Quaracchi 1902, p. 269, col. 3). From this same short work (chaps. 17, 49, and 50) the first two paragraphs of Meditation VII in the series of *Meditations* attributed to St Anselm were extracted (PL 158, 709-820) toward the end of the twelfth century.
A. Wilmart, examining the many manuscripts of the *De spiritu et anima* (in English libraries alone he counted about sixty), is of the opinion that the work was originally conceived in three books: this would explain the principal differences among the manuscripts. The first to attribute the short work to A. in the modern age was the Benedictine P. Coustant (*Admonitio in libro de Spir. et Anima*: PL 40, 779).
II. *De diligendo Deo*, likewise published by Coustant in an appendix to the works of St Augustine (PL 40, 847-64): a book which, in the judgment of Erasmus, is “pious and not devoid of learning.” The thoughts of which it is composed are drawn largely from Hugh of Saint-Victor, St Bernard, and St Anselm. Vincent of Beauvais (*Speculum nat.*, XXIII, 1) cites it under the name of Peter Comestor (q.v.); but the Benedictines prefer to consider it the work of A.
III. The same Benedictines (Coustant and the Maurists, authors of the *Histoire Littéraire de la France*) attribute to A. also the following short works:
1. The *Manuale*, which appears in an appendix to the works of Augustine (PL 40, 951-68), compiled from extracts of Augustine, Cyprian, Gregory the Great, Hugh of Saint-Victor, etc.: a short work famous in the Middle Ages, which Wilmart—observing that the fourteenth of the *Meditations* attributed to St Anselm derives from it—considers composed by a pious compiler at the beginning of the thirteenth century.
2. The *Soliloquiorum animae ad Deum liber unus*, likewise in an appendix to the works of St Augustine (PL 40, 863-98): dependent on the writings of Augustine and Hugh of Saint-Victor; not to be confused with Augustine’s authentic *Soliloquies*.
3. The *Liber Meditationum*, likewise in an appendix to St Augustine (PL 40, 901-42).
These three works still enjoy wide circulation, both in Latin and in modern languages, under the name of St Augustine.
4. Books I and III of the *De anima*, edited in an appendix to the works of Hugh of Saint-Victor (PL 177, 165): books which correspond, Book I to the *Meditaciones piissimae de cogitatione humanae conditionis* (PL 184, 485-508), and Book III to the treatise *De interiori domo, seu de conscientia aedificanda* (PL 184, 507-52): writings published in an appendix to the works of St Bernard.
It should be noted, however, that to guarantee all these attributions in favor of A., there is still—given the present state of our knowledge concerning the manuscript tradition of these short works—no positive evidence.
Finally, we do not know whether A. satisfied the desire of Isaac of Stella, who in his epistle *De anima* begged him to write to him on the “structure of the human body”; it is thought that at least the *De spiritu et anima* may have been a consequence of this.