Skip to main content

Psellus, Michael (Baptized Constantine)


(b. near Constantinople, 1018; d. Constantinople April/May 1078)

philosophy, transmission of knowledge.

Born in a western suburb of Constantinople near the monastery of Narses,1 psellus belonged to an aristocratic but impoverished family originally from Bithynian Nicomedia. He studied under Nicetas of Byzantium and John Mauropus, but at the age of sixteen was forced by financial need to enter the Byzantine provincial administration. On the death of his sister, he returned to Constantinople and entered the legal profession. He became associated with the court of Michael IV Paphlagon (1034–1041) and was soon appointed judge in Philadelphia, under the protection of his former schoolmate Constantine Leichudes. During the brief reign of Michael V Calaphates (1041-1042), Leichudes became prime minister and Psellus the head of the imperial secretariat. During these years of developing his political career Psellus had continued his studies independently; and when Constantine IX Monomachus (1042–1055) reorganized higher education in Constantinople, Psellus became the head of the philosophical faculty (1045–1054) while retaining his high position at the court.

His teaching of pagan, and particularly Neoplatonic, philosophy, however, combined with the jealousy of his political rivals, opened the way for attacks upon Psellus. In 1053 he was forced to reaffirm his religious orthodoxy in a confession of faith.2 His troubles were compounded by the death of his only child, his daughter Styliane.3 Finding his relations with the emperor worsening, Psellus pleaded illness and retired to the monastery of Olympus in Bithynia in 1054; upon becoming a monk, he took the name Michael. On the death of Constantine in 1055, however, he was recalled to a position of influence in Constantinople by Empress Theodora (1055–1056) and participated in the intrigues that resulted in the elevation of Isaac I Comnenus (1057–1059) to the throne.

Although he had previously composed a group of works on alchemy, divination, and the like4 for Patriarch Michael Caerularius (1043–1058), Psellus now attacked him for his interest in these nefarious subjects.5 But, with the accession of a new emperor, Constantine X Ducas (1059–1067), Psellus was forced by his former protector, Leichudes, who had succeeded Caerularius as patriarch (1059-1063), to honor his monastic vows; he was forced to stay at the monastery of Narses, near his birthplace, from 1059 to 1063. In the latter year his old friend John Xiphilinus became patriarch and allowed Psellus, upon delivering a eulogy of Caerularius, to leave the monastery and return to his political activities. His influence at court continued, with various vicissitudes, until his death in April or May of 1078.6

During his very active political life Psellus found time to write an astonishing number of works: letters, history, poems, essays, orations, and treatises on grammar, rhetoric, law, philosophy, and science. An autodidact in philosophy and science, he was instrumental in reviving an interest in those subjects in Byzantium. In particular, he was concerned to promote later Neopiatonism and its theurgical component. He accepted the idea that a knowledge of the divine is acquired in stages through a study of the sensible objects in this world, followed by a thorough investigation of mathematics, which leads directly to theology.7 In this spirit he wrote compendia of excerpts8 concerning the sciences and theology derived from various sources; since some of these sources are otherwise lost to us, Psellu’ excerpts are frequently of great historical value. He also was instrumental in preserving for us various works of laniblichus and Proclus9, and one version of the Corpus Hermeticum.10 He was not an original thinker but did his best to explain what he had learned; his best in technical subjects, such as chronology,11 is not very impressive. Through his interpretation we are able to gain access to the theurgy, demonology, and alchemy of the third, fourth, and fifth centuries, an access extremely valuable to intellectual historians. Also, Psellus’ activities stimulated in others an interest in philosophy and science. These two contributions more than compensate for the derivative character of the material he so assiduously compiled.

A list of Psellus’ works on philosophy and science is given below. For unpublished treatises, see G. Weiss, “Untersuchungen zu den unedierten Sehriften des Michael Psellos,” in BvlavTivd, 2 (1970), 335–378, reprinted with corrections, ibid., 4 (1972), 1–52. Collected works are Bidez: J. Bidez, Catalogue des manuscrits alchimiques grecs, VI (Brussels, 1928); Boissonade: J. F. Boissonade, Michael Psellus De operatione daemonum (Nuremberg, 1838; repr. Amsterdam, 1964); Boissonade,Anccdota: J. F. Boissonade,Anecdota Graeca, I (Paris, 1829), 175–247; Boissonade, Tzetzes: J. F. Boissonade, Tzetzae Allegoriae lliados. Acceduni Pselli Allegoriae quarum una inedita (Paris, 1851; repr. Hildesheim, 1967), 341–371; Ideler: I. L. Ideler, Physici et medici Graeci minores, 2 vols. (Berlin, 1841–1842; repr. Amsterdam, 1963); Kurtz and Drexl: Kurtz and Drexl: E. Kurtz and F. Drexl, Michaelis Pselli Scripta minora, 2 vols. (Milan, 1936–1941); PG 122: J.-P. Migne, Patrologia Graeca, vol. 122 (Paris, 1889), cols. 476–1186; Sathas: C. N. Sathas, Bibliotheca Graeca Medii Aevi, IV and V (Paris, 1874–1876); Weinstock: S. Weinstock, Catalogus codicum astrologorum Graeco-rum, IX, pt. 1 (Brussels, 1951), 101–128.

I. Philosophy

Ia. In general. “That the Movements of the Soul Resemble the Motions of the Heavenly Bodies,” in Boissonade, Michael Psellus, 56–57; and PG 122, cols. 1075–1076; “On Philosophy,” in Kurtz and Drexl, 1, 428–432; “To Those Who Ask How Many Are the Kinds of Philosophical Discourses,”ibid., 441–450; “That Substance Is a Self-Subsistent,” ibid, 451–458; and “Greek Arrangements Concerning the Divine Creation,” in Weinstock, 111–114. See also M. Sicherl, “Platonism und Textiiberlieferung,” in Jahrbuch derÖsterreichischen Byzantinischen Gesellschaft, 15 (1966), 201–229, esp. 206–212.

Ib. Plato. “On Plato’ Psychogony,” edited by A.J.H. Vincent, “Notice sur divers manuscrits grecs relatifs à la musique,” in Notices et extraits des manuscrits, XVI, pt. 2 (Paris, 1858), 1–600, esp. 316–337; C. W. Linder, editor, M. Pselli in Platonis De animae Procreatione praecepta commentarius (Uppsala, 1854); and PG 122, cols. 1077–1114. That this work is based on Proclus’ commentary on the Timaeus is shown by J. Bidez, “Psellus et le Commentaire du Timée de Proclus,” in Revue de Philologie, new series 29 (1905), 321–327; “Commentary on the Platonic Chariot-Driving of the Souls and the Army of the Gods in the Phaedrus,” in Kurtz and Drexl, I, 437–440, based on Hermeias’ commentary on the Phaedrus; and “On the Ideas Which Plato Mentions,” ibid., 433–436, based on Plotinus. Psellus also exertpted passages from Proclus’ commentary on Plotinus’ Enneads; see L. G. Westerink, “Exzerpte aus Proklos’ Enneaden-kommentar bei Psellos,” in Byzantinische Zeitschrift, 52 (1959), 1–10.

Ic. Aristotle. In Physicen Aristotelis Commentarii, Latin translation by I.B. Camotius (Venice, 1554). Part of the beginning of the Greek text was edited by C.A. Brandis in Aristotelis Opera, IV (Berlin, 1836; repr. Berlin, 1961), 322b-324a; and Bidez, 211–212. A complete edition is promised by L. Benakis; for now see P. Joannou, Christliche Metaphysik in Byzanz I. Die Illuminationslehre des Michael Psellos und Joannes Italos (Ettal, 1956); L. Benakis, “Studien zu den Aristoteles-Kommentaren des Michael Psellos,” in Archiv für Geschichte der Philosophie, 43 (1961), 215–235, and 44 (1962), 33–61; “Michael Psellos’ Kritik an Aristoteles und seine eigene Lehre zur “Physis’-und “Materie-From’-Problematik,” in Byzantinische Zeitschrift, 56 (1963), 213–227; and “Doxographische Angaben über die Vorsokratiker im unedierten Kommentar zur “Physik’ des Aristoteles von Michael Psellos,” in Κάρις Κωνσταντίνω̨ ̓Ι. Βо½ρβέρῃ (Athens, 1964), 345–354. “Opinions Concerning the Soul,” PG 122, cols. 1029–1076, is based on John Philoponus” commentary on Aristotle’ De anima; see also E.A. Leemans, “Michel Psellos et les Δо́ξαι περὶ ψυχη̑ς,” in L’antiquité classique, 1 (1932), 203–211; and a collection of four meteorological tracts, in Bidez, 49–70, based on Olympiodorus’s commentary on Aristotle’s Meteorologica. C. Zervos in Un philosophe néoplatonicien…mentions two other works, but I have not been able to check their existence and the reliability of their attribution to Psellus: Paraphrase of the De interpretatione (Venice, 1503), Latin translation by S. Boetius (Venice, 1541) and by C. Gesner (Basel, 1542); and Synopsis of Aristotle’s Logic, edited by E. Ehingerus (Vienna 1597).

Id. Theurgy. “Commentary on the Chaldaean Oracles,” edited by J. Opsopoeus, in Oracula magica Zoroastris (Paris, 1607), 52–113; PG 122, cols. 1123–1150. See also N. Terzaghi, “Parergon de quibusdam Oraculis chaldaicis,” in Studi italiani di filologia classica, 16 (1908), 433–440; “Brief Exposition of the Doctrines of the Chaldaeans,” in Ospsopoeus, op. cit., 112–121; PG 122, cols. 1149–1154; and D. Bassi “Notizie di codici greci nelle bibliotheche italiane III; Michele Psello,” in Rivista di filologia e d’istruzione classica, 26 (1898), 122–123; and “Summary Description of the Ancient Doctrines of the Chaldaeans,’ in W. Kroll, De Oraculis Chaldaicis (Breslau, 1894; repr. Hildesheim, 1962), 73–76. Psellus made two excerpts from Proclus’ commentary on the Chaldaean Oracles: Proclus From the Chaldaean Philosophy, edited by A. Jahn (Halle, 1891), and “Proclus on the Hieratic Art According to the Greeks,” in Bidez, 137–151.

That Psellus’s knowledge of the Chaldaean Oracles is derived from Proclus is demonstrated by Kroll, op. cit.; J. Bidez, “Proclus περὶ τη̑ς ίερατικη̑ς τένης,” in Annuaire de l’Institute de Philologie et d’histoire orientales et slaves, 4 (1936), 85–100; and H. Lewy, Chaldaean Oracles and Theurgy (Le Caire, 1956), 473–479. See also E. Des Places, “Le renouveau platonicien du XI[sup(e)] siècle: Michel Psellus et les Oracles chaldaïques,” in Comptes rendus de l’Académie des Inscriptions et Belles-lettres (1966), 313–324; “On Sacrifice,” in Bidez, 155–158; and “different Greek Opinions About the Soul,” in Weinstock, 106–111. M. Sicherl, “Michael Psellos und Iamblichus De mysteriis,” in Byzantinische Zeitschrift, 53 (1960), 8–19, has shown that Psellus wrote the scholium that appears at the beginning of the De mysteriis in all extant manuscripts, in which it is stated that Proclus attributed the work to Iamblichus, and that he also wrote the lemmate. Various of Psellus’ excerpts from the De mysteriis are in Weinstock, 114, and in M. Sicherl, Die Handschriften, Ausgaben und Übersetzungen von Iamblichos De mysteriis (Berlin, 1957), 134–137.

Ie. Corpus Hermeticus. R. Reitzenstein, Poimandres (Leipzig, 1904), 319, surmised that Psellus’ manuscript of the Corpus was the ancestor of the extant ones and that he made some corrections and additions to the text (p. 326). Indeed, one manuscript of the fourteenth century (Vat. Gr. 951) contains a scholium by Psellus on Corpus Hermeticum I, 18, which is in Boissonade, Michael Psellus, 153–154; PG 122, cols. 1153–1156; and Reitzenstein, op. cit., 333–334. There are other indications that Psellus had read the Corpus : for example, Bidez, 214–215, 218. But it seems most probable that only the text of Vat. Gr. 951 represents the recension of Psellus, and that the other manuscripts descend from an independent archetype—see A. D. Nock and A.-J. Festugière, Corpus Hermeticum, I (Paris, 1945), xlix–li.

If. Demonology. “Timotheus, or On the Operation of Demons,” in Boissonade, Michael Psellus, 1–36; PG 122, cols. 819–976. See also M. Wellnhofer, “Die thrakischen Euchiten und ihr Satanskult im Dialoge des Psellos ‘Tιμо́θεоς ἠ περὶ τω̑ν δαιμо́νων’,” in Byzantinische Zeitschrift, 30 (1929–1930), 477–484; “What the Greeks Thought About Demons,” in Boissonade, Michael Psellus, 36–43; PG122, cols. 875–882; “On Demons,” in Bidez, 113–131; “Greek Classifications of Demons,” in Weinstock, 114–120. See also A. Delatte and C. Jesserand, “Contribution à l’étude de la démonologie byzantine,” in Annuaire de l’Institut de philologie et d’histoire orientales, 2 (1934), 207–232; K. Svoboda, La démonologie de M. Psellos (Brno, 1927); and P. Joannou, Démonologie populaire—démonologie critique au XIe siècle. La vie inédite de S. Auxence par M. Psellos (Wiesbaden, 1971).

Ig. Marvels. The following four works apparently were all addressed to the Patriarch Michael Caerularius: On the Powers of Stones, edited by P. J. Maussacus and J. S. Bernard (Leiden, 1745); Ideler, I, 244–247; and PG 122, cols. 887–900; “On Marvelous Readings,” edited by A. Westermann, in Scriptores rerum mirabilium Graeci (Brunswick-London, 1839), 143–148; “On Looking at Shoulder-Blades and Birds [as Omens],” edited by R. Hercher, in Philologus, 8 (1843), 166–168; and “On How to Make Gold,” in Bidez, 1–47.

Ih. Astrọlogy. “Solutions of Astrological Questions in Thirty Chapters"—what appears to be the unique manuscript, Monacensis Gr. 537, fols. 1–8v, ends in the middle of the sixth chapter; “On Seven-Month, Eight-Month, and Nine-Month Embryos,” in Weinstock, 101–103; and “Is Astrology True?” edited by M. A. Šangin, in Catalogus codicum astrologorum Graecorum, XII (Brussels, 1936), 167.

II. Science.

IIa. Encyclopedias. “Instruction of All Sorts,” edited by L. G. Westerink, appeared as Michael Psellus. De omnifaria doctrina (Utrecht, 1948). Four different redactions were composed by Psellus : “Brief Solutions of Physical Problems,” in 137 sections; “Brief Solutions and Explanations of Physical Problems,” in 193 sections, dedicated to Michael VII Ducas (1071–1078; co-emperor from about 1060); “Synoptic Answers and Explanations to Different Questions and Problems,” in 201 sections, also dedicated to Michael; and “Instruction of All Sorts and Entirely Necessary,” in 193 sections, addressed to Michael after he had become sole emperor in 1071. Westerink follows the order of “Synoptic Answers…,” the longest redaction. See also P. Tannery, “Psellus sur la grande année,” in Revue des études grecques, 5 (1892), 206–211, reprinted in his Mémoires scientifiques, IV (Toulouse-Paris, 1920), 261–268; and F. Boll, “Psellus and das ‘grosse Jahr,’ “ in Byzantinische Zeitschrift, 7 (1898), 599–602. “Solutions to Various Problems” is in Boissonade, Michael Psellus, 63–69. Not by Psellus is Brief Solutions to Physical Problems, in two books, edited by G. Seebode (I, Gotha, 1840; II, Wiesbaden, 1857); and PG 122, cols. 783–810. In reality this is an incomplete text of Symeon Seth’s “Synopsis of Physical Problems,” edited by A. Delatte, in Anecdota Atheniensia et alia, II (Paris, 1939), 1–89. On this work see also C. Giannelli, “Di alcune versioni e rielaborazioni serbe delle ’Solutiones breves quaestionum naturalium’ attribuite a Michele Psello,” in Studi byzantini e neoellenici, 5 (1939), 445–468, reprinted in ibid., 10 (1963), 1–25.

IIb. Numbers. “On the Properties of Numbers,” in Weinstock, 103–106; “On Numbers,” in P. Tannery, Revue des études grecques, 5 (1892), 343–347, reprinted in his Mèmoires scientifiques, IV (Toulouse-Paris, 1920), 269–274; “From Diophantus’ Arithmetic,” edited by P. Tannery, in Zeitschrift für Mathematik and Physik, Historisch-literarische Abtheilung, 37 (1892), 41–45, reprinted in his Mémoires scientfiques, IV, 275–282, also in Diophanti Alexandrini Opera omnia, II (Leipzig, 1895), 37–42—these three works were apparently extracted from lamblichus’ Collection of Pythagorean Dogmas; and “On the Purpose of Learning Geometry,” in Boissonade, Michael Psellus, 159–163.

IIc. Music. “Introduction to the Science of Rhythm,” edited by J. Cäsar, in Rheinisches Museum für Philologie, new series 1 (1842), 620–633—see also R. Westphal, Griechische Rhythmik and Harmonik, second edition (Leipzig, 1867), supplement, 18–21. Three fragments on music are published as Psellus’ by A. J. H. Vincent, op. cit., 338–343; they belong to an Anonymus De musica (Paris, 1545), which Vincent claims is entirely by Psellus. But this work seems to be a part of the Anonymi logica et quadrivium, edited by J. L. Heiberg (Copenhagen, 1929), which was once incorrectly ascribed to Psellus; see also L. Richter, “‘Des Psellos kurzen Inbegriff der Musik’ bei L. Chr. Mizler,” in Studia Byzantina (Halle, 1966), 149–157.

IId. Chronology. Psellus’ work on chronology was partially edited by A. Mentz in Beiträge zur Osterfestberechnung bei den Byzantinern (Königsberg, 1906), 102–108; the complete text was edited by G. Redl, “La chronologie appliquée de Michel Psellos,” in Byzantion, 4 (1927–1928), 197–236, and 5 (1929), 229–286. See also G. Redl, “Untersuchungen zur technischen chronologie des Michel Psellos,” in Byzantinische Zetschrift, 29 (1929–1930), 168–187, and “Studien zur techischen Chronologie des Michael Psellos, “ in Byzantinische-neugriechische Jahrbicher,, 7 (1930), 305–351.

IIe. Medicine. “Medical Work in Iambs,” in Boissonade, Anecdota, 1750232; and Ideler, I 203–243; “On Common Terms in Illnesses,” in Boissonade, Anecdota, 233–241; “Bathing,” in Ideler, II, 193; and “On Foods and Drinks,” ibid, 257–281—see also E. Renuad, “Queslques termes médiaux de Psellos,” in Revue des etudes graceques, 24 (1909), 251–266.

IIf. Minor seicentific works. “On Athenican Places and Names,” in Boissondade, Michael Psellus, 44–48; and PG 122, cols. 1155–1160; and “On Agriculture,” in Boissonade, Anecdota, 242–247.


1. P. Jaonnou, “Psellos ed le Monastére τὰ Ναρσоν͂,” in Byzantinische Zeitschrift, 44 (1951), 283–290.

2. Garzya, “On Michael Psellus’ Admission of Faith,” in ̒Επετηρὶς ̒Εταιρείας Βυζαντινω̑ν σπоυδῶν, 35 (1966–1967), 41–46.

3. A. Leroy-Molinghen “Styliane,” in Byzasntion, 39 (1969), 155–163. On Psellus’ adopted daughter see R. Guilland, “À propos d’un texte de Psellos,” in Byzantionoslavica, 20 (1959), 205–230, and 21 (1960), 1–37, repr. in is Recherches sur les institutions byzantines, I (Berlin-Amsterdam, 1967), 84–143; and A. Leroy-Molinghen, “La déscedance adopative de Psellos,” in Byzantion, 39 (1969), 284–317; and “À proos d’un jugement rendu contre Psellos,” ibid., 40 (1970), 238–239.

4. See section lg. in text.

5. L. Bréhier,“Un discours inédit de Psellos. Accusation de patriarche Michel Cérulaire devant la Synode (1059),” in Revue des études graceues, 16 (1903), 375–516, and 17 (1904), 35–76.

6. P. Gauiter,“Monodie inedite de Michel Psellos sur le Basileus Andronic Doucas,” in Revue des études byzantines, 24 (1966), 153–170.

7. S.A. Sofroniou, “Michael Psellos’ theory of Science,” in ̓Αθηνᾶ, 69 (1966–1967), 78–90.

8. See section IIa. in text.

9.Ibid. Id.

10.Ibid. Ie.

11.Ibid. IId.


Much of our information about Psellus comes from his Chronography, which is a history of Byzantium from 976 to 1077; the best ed. is by E. Renauld, 2 vols. (Paris, 1926–1928); see also R. Anastasi, Studi sulla Chronographia di Michael Psello (Catania, 1969). Additional information is in his orations and letters, some of which are in Boissonade, Michael Psellus, 170–188, PG 122, cols. 1161–1186; Saths, V; and Kurtz and Drexl; see also J. Darrouzés indites de Psellus,” in Reveu des etudes byantines, 12 (1954), 177–180. Still useful is C. Zervos, Un philosophe néoplatonicien du XIe siecle. Michael Psellos (Paris, 1920). The most recent, but not entirely satisfactory, study is the article by E. Kriaras in Pauly-Wissowa, Real-Encyclopädie der classischen Altertumswissenschaft, supp. XI (Stuttgart, 1968), cols. 1124–1182, trans. into Greek in Βυζαντινά4 (1972), 53–128.

David Pingree

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Psellus, Michael (Baptized Constantine)." Complete Dictionary of Scientific Biography. . 21 Aug. 2017 <>.

"Psellus, Michael (Baptized Constantine)." Complete Dictionary of Scientific Biography. . (August 21, 2017).

"Psellus, Michael (Baptized Constantine)." Complete Dictionary of Scientific Biography. . Retrieved August 21, 2017 from

Learn more about citation styles

Citation styles gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, cannot guarantee each citation it generates. Therefore, it’s best to use citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

The Chicago Manual of Style

American Psychological Association

  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.