BMCR 2019.09.58

The Astrological Autobiography of a Medieval Philosopher: Henry Bate’s Nativitas (1280-81). Ancient and Medieval Philosophy Series 1, 17

, , , , The Astrological Autobiography of a Medieval Philosopher: Henry Bate's Nativitas (1280-81). Ancient and Medieval Philosophy Series 1, 17. Leuven: Leuven University Press, 2018. 320. ISBN 9789461662699 €85,00.


The volume under review contains the first complete scholarly edition of the Nativitas of Henry Bate as well as a collection of seven introductory chapters that provide background material about Bate’s biography, working methods, and astrological learning. The Nativitas was a natal horoscope that Bate cast in 1280, possibly in response to anxieties about the course of his career. Rather than restricting himself to astrological technicalities, however, Bate used the horoscope as a frame on which to hang a detailed narrative of his own life and engage in introspective self-analysis. The result is a unique and fascinating work that combines technical astrological analysis with a revealing exploration of Bate’s career, personal proclivities, and physical health, among other subjects.

In the opening chapter of the introduction David Juste and Carlos Steel survey the manuscript tradition of Bate’s work. Five complete manuscripts of the Nativitas survive, as well as four fragments. The textual tradition is divided into two branches, one represented by a single fifteenth-century manuscript from Segovia, the other by four manuscripts all deriving from a lost exemplar that may have belonged to William of Saint-Cloud, who appended his own nativity in imitation of Bate’s in his copy of the manuscript. All significant variants are included in Steel’s apparatus criticus. The most noteworthy divergence between the Segovia manuscript and the four others is that the former uniquely preserves Bate’s autobiographical report on the series of events that took place in his 35th year (March 1280-March 1281), whereas the other manuscripts contain an astrological prediction of what would happen during that year.

The second chapter, by Steel and Steven Vanden Broecke, provides a biographical sketch of Bate’s life. Born in Mechelen (Malines) in the Low Countries in 1246 to a prominent local family, he studied at Paris in the 1260’s and obtained the degree of master. Bate later returned to Mechelen and acquired a series of ecclesiastical benefices, culminating in the position of cantor at the cathedral of Liège. He served as a tutor in some capacity to the young nobleman Guy of Avesnes, and after Guy became bishop of Utrecht in 1301, he dedicated to him the Speculum divinorum, a massive philosophical encyclopedia. Bate wrote widely on astronomy and astrology; his works (usefully summarized by David Juste) include a treatise on the astrolabe dedicated to William of Moerbeke and a work on astrological medicine (the De diebus creticis). In addition, the planetary tables that he devised for the coordinates of Mechelen, the Tabule Machlinenses, were the earliest set of original astronomical tables compiled in the Latin West. 1 Bate also collaborated in translating several of the astrological treatises of the Spanish Jewish scholar Abraham Ibn Ezra (c. 1089-c. 1161) into Old French and Latin, and he would go on to make liberal use of Ibn Ezra in his work. Shlomo Sela, who has edited a number of Ibn Ezra’s works, details the relationship between Bate and Ibn Ezra in a separate chapter.

Bate was one of the most learned and accomplished astrologers of his era, and the sophisticated techniques that he used to cast and analyze his natal horoscope will presumably be unfamiliar to non-specialist readers. Steven Vanden Broecke provides a partial summary of Bate’s techniques, including reproductions of four astrological charts that Bate compiled, in an introductory chapter; this is one area in which the book might have been usefully expanded. In casting a natal horoscope, it was of the utmost importance to know the precise hour and minute of the subject’s birth. Bate relates (p. 128) that he questioned his mother and other women who were present at his birth, all of whom agreed that he was born slightly after midnight on the Saturday before Palm Sunday in 1246. Even this knowledge was insufficient for his purposes, however, since Bate needed to know the precise degree of the ecliptic that was rising at the moment of his birth (the ascendant). The various methods employed to determine the ascendant with greater precision were known collectively as ‘rectification.’ Bate relied upon a method (the trutina Hermetis or ‘balance of Hermes’) derived from the Sefer ha-Moladot (or Book of Nativities) of Ibn Ezra, which established that the position of the moon at birth was the same as the ascendant at conception, and vice versa. This method required the astrologer to know the moment of conception of his subject, which, as Sela points out in his edition of the Sefer ha-Moladot, rendered its utility limited. 2 In any case, as Vanden Broecke describes, Bate worked backwards from the information he had about the time of his birth to arrive at a precise date for his conception. Then, having determined that the ascendant degree at his conception was Gemini 17°, he calculated the positon of the moon as Sagittarius 12° 20′; according to the trutina Hermetis this was also his ascendant degree at birth. This is one of several places where a more detailed discussion of Bate’s astronomical methods would have been useful. Since a precise knowledge of the time of birth was needed to generate the ascendant degree of the ecliptic, it is difficult to see how any amount of mathematical shuffling could result in a more accurate number for the ascendant if the hour of birth had not been carefully observed; and indeed, the process of rectification was open to all kinds of abuse.

After establishing the ascendant, the astrologer divided the 360 degrees of the ecliptic into twelve houses. This was not usually done by simply assigning 30 degrees to each house (though Bate does refer to a hypothetical house division secundum gradus equales at various points), but typically by dividing each of the four great arcs (those bounded by the ascendant, the lower midheaven, the descendant, and the midheaven) into three arcs with equal rising times. This could be done using a table of ascensions, which calculated the rising times of the signs of the zodiac for different latitudes; the editors do not discuss Bate’s methodology in detail here except to say that he must have composed tables of ascension for the latitude of Mechelen. The intrepid reader can use Ptolemy’s Almagest (2.9), which contains an entry for latitude 51°30 (quite close to Mechelen) to get a very rough confirmation of the accuracy of Bate’s house cusps (i.e., the boundaries between houses).3 The astrologer next used planetary tables to calculate the longitude of the planets (including the sun and moon) in the ecliptic for the moment of his birth and assign them to their proper houses. The application of the information contained in such tables was by no means simple, since the astrologer had to take into account not only the deferents and epicycles of Ptolemaic planetary theory, but also factors such as the gradual movement of the longitude of the apogee of the deferent circle over time due to the precession of the equinoxes, and the necessary adjustments caused by Ptolemy’s use of the equant, i.e., a point equidistant from the earth and the center of the deferent circle, from which the angular speed of the epicycle appeared to be uniform.4 Ptolemy had included tables of planetary motion in the Almagest – later revised and separated out in the Handy Tables – and in the twelfth and thirteenth centuries The Tables of Toledo, which were compiled in Islamic Spain in the second half of the eleventh century, became a standard tool in the Latin West. Bate, however, maximized the accuracy of his own natal horoscope by composing his own tables for the longitude of Mechelen, and correcting them in accordance with his own observations down to the end of his life.

Once the technical work of dividing up the houses and assigning the planets to them had been completed, the equally complex, but more creative, work of astrological analysis began. Each of the twelve houses had its own particular signification; the first house, for example, determined ‘the complexion and form of the body’ and ‘the quality of the soul,’ while the eighth house presaged the time and manner of death. The relationship (‘aspect’) between planets was of paramount importance as well. Bate devotes the most attention (some 26 pages of Latin text in this edition) to the first house, which stretched from Sagittarius 12° 20′ to Capricorn 19°. Because Sagittarius, the sign under which Bate was born, was governed by Jupiter, Bate interpreted his complexion as sanguine. The fact that the malign planet Saturn, however, stood in a sextile aspect to Bate’s ascendant (i.e., it was separated by approximately 60° of ecliptic longitude) meant that he was also characterized by slowness ( tarditas) and lethargy ( pigritia). Bate proceeds through each of the twelve houses in order, citing a wide variety of astrological authorities to justify his interpretation of the data (indeed, as David Juste notes in his discussion of the astrological context of the Nativitas, there is virtually no contemporarily available astrological source that Bate was not aware of). Of particular interest are his descriptions of various medical afflictions that he suffered from throughout his life. Naturally, because Bate was analyzing his natal horoscope thirty-five years after he was born, there was ample room for him to adjust his interpretation of the data to correspond with the known events of his life.

This is the first complete Latin edition of Bate’s Nativitas, and it is an impressive scholarly achievement whose depths can only be hinted at in this review. Not only have the editors produced the definitive edition of Bate’s text, they have also written what amounts to a separate monograph to contextualize it. The audience for this work will probably be restricted to readers who know Latin and have some knowledge of the techniques of medieval astrology. It thus provides an opening for a scholar willing to translate the Nativitas and explain its techniques to a broader readership.

This is a very clean book, especially considering the labors involved with publishing a text of this kind. A few minor suggestions are noted below, none of which should be seen to detract from an impressive piece of scholarship that will help to make Bate’s work much more and accessible, and which also serves as a fine example of the benefits of working in scholarly teams.

On pp. 19 and 37 the Latin Responsum autem ultimo facere ardenti petitioni conveniens protelando amicis imponebatur is translated ‘For it is incumbent upon friends to finally give a suitable response to an urgent request by delaying it,’ but that cannot be what this passage means. The Latin is inelegant, but perhaps ‘Ultimately, because of his delaying, the [obligation] to provide a suitable response to [Bate’s] urgent entreaty fell upon his friends.’

p. 20: ‘conjunctives’ for ‘subjunctives’ may confuse Anglophone readers.

p. 21: something has gone wrong with the translation ‘that the revolutions of the year to not add many force to the nativity,’ which is translated correctly three pages earlier.

p. 28: should be ‘similar [to] the text’

p. 32: ‘we have no that evidence’ should be ‘we have no evidence that’

p. 42: in a passage translating Nativitas 1308-1320 on Bate’s proficiency with various musical instruments, a number of corrections need to be made. Bajulare means not ‘carry’ but ‘regulate’ or ‘control’ (See Du Cange, s.v.); in reference to the playing of the viella (‘viol’ or ‘fiddle’), tactum cordarum should be fingering or touching of ‘chords’ rather than ‘snares’; fides (‘strings’) is left untranslated in the phrase cistri fides (‘strings of the citola’); For the Latin Novit… delectabile murmur tubisoni Licii penne plectro replicare ictibus timpanizando vicissim replicatis the translation ‘[he knew how ]to replicate the delightful sound of the Lycian trumpet by playing the tympan with beats replicated in turn’ does not make sense. The three previous references have all been to stringed instruments (the viella, the citola, and the psaltery) and the words penne plectro – left out in this translation – refer to the use of a quill pick or plectrum to strike strings. Though admittedly obscure, it seems to mean something like ‘[he knew how] to replicate the delightful sound of the resounding lyre with a quill plectrum, striking with beats replicated in turn.’


1. Philipp E. Nothaft, ‘Henry Bate’s Tabule Machlinenses : the earliest astronomical tables by a Latin author,’ Annals of Science 75.4 (2018).

2. Shlomo Sela, Abraham Ibn Ezra on Nativities and Continuous Horoscopy (Leiden, 2013), p. 43.

3. See John D. North, Horoscopes and History (London, 1986), pp. 9-10.

4. By far the most useful introduction to the complexities of Ptolemaic planetary theory is found in James Evans, The History and Practice of Ancient Astronomy (New York, 1988), pp. 289-392.