Roger Bacon

Life and Works of Roger Bacon

by Yael Kedar

A cloud of uncertainty envelops many details of Bacon’s life. His date of birth is but one example. The disagreement between scholars  concerning that date revolves around a passage from the Opus tertium (written in 1267), in which Bacon reports that 40 years had passed since he had first learned the alphabet, and that except for two years he had been in studio ever since (Opus tertium 20, 65). The various estimated dates result from the different interpretations attached to the phrases didici primo alphabetum and in studio. If in studio is taken to be “in a University”, then Bacon’s date of birth should be set to 1214 (This is the view held by Sharp, 1930, 12; Easton, 1952, 1–12; Maloney, 1988, 2; and Hackett, 1997, 11).  However, if the phrase “learned the alphabet” should be interpreted literally, then the forty-years-period should be counted from the beginning of Bacon’s primary education. Accordingly, his date of birth should be set in 1219 or 1220 (This is the opinion of Crowley, 1950, 18; Crombie and North, 1970, 377; Lindberg, 1983, xvi; and Clegg, 2003, 8).

The details of Bacon’s education are, again, doubtful. He was probably matriculated first at Oxford. The date of his M.A. degree would be about 1240, assuming that he was born in 1220 and that a scholar typically earned the M.A. at the age of 20 (Lindberg, 1983, xvii).

Bacon went to Paris in the early 1240s – surely before 1245, since he reports to have seen Alexander of Hales (ca. 1183–1245), who died in that year (Opus minus, 325). Easton (1952, 34) thinks he first taught at Oxford for a few years, thereby deepening his knowledge of Aristotle and the commentators, and perhaps gaining some reputation. He suggests that, on the strength this reputation, Bacon was invited to Paris when the faculty of arts in that university needed a man to teach Aristotle. Little and Steele (1914, 4; 1921, 129) make a similar point, suggesting that Bacon’s reputation was good enough for him to be taken up by the Chancellor of Paris, Philip (1160s–1236), and recommended to pursue further studies in medicine. The outcome of these studies was the Epistola de accidentibus senectutis, dedicated and sent to Innocent IV.

Since Philip died in 1236, Steele holds to the view that Bacon came to Paris in the late 1230s rather than the early 1240s and explains the gap between Bacon’s arrival in Paris and the dates of his recorded lectures (from 1244 to 1247), by the assumption that he spent the interval studying medicine. Crowley (1950, 24–25), however, claims that the Epistola was wrongly attributed to Bacon. He argues that the entire case for Bacon’s authorship rests on a reference to the Opus majus which it contains, which is clearly a later addition, since the Epistola was dedicated to Pope Innocent IV, who died in 1254, about thirteen years before the composition of the Opus majus.  Moreover, in the Opus majus and in several other works Bacon refers to the Epistola, and in none of these passages does he suggest that he himself was the author. Crowley concludes that since the Epistola is the only alleged evidence of Bacon’s early arrival to Paris, there is no reason left to assume that this arrival occurred in the 1230s.

In Paris Bacon heard William of Auverge (d. 1249) disputing on the agent intellect (Opus majus 2.5) and John of Garlandia (1190–1255) denouncing the ignorant etymologists (Compendium studii philosophiae, 453). He may have become acquainted there with Albertus Magnus (ca. 1200–1280), who was in Paris at the same time (Crombie and North, 1970, 377), and he may have been Robert’s Kilwardby’s student (Weisheipl, 1965, 79). During the 1240s Bacon was lecturing in the faculty of arts at Paris. His lectures covered Aristotle’s Metaphysics, Physics, De sensu et sensato, probably De generatione et corroptione, De animalibus and De anima perhaps also De Caelo et mundo, De causis and De plantis (Easton, 1952, 49). It thus appears that Bacon was one of the early lecturers, perhaps indeed a pioneer, on Aristotle’s libri naturales in Paris after the bans of 1210, 1215, 1233 (Crombie and North, 1970, 7; Lindberg, 1983, xvii; Weisheipl, e, 454; Maloney, 1988, 4). His Quaestiones were probably the lectures he gave in class, copied down much as he gave them in Paris. Besides those, Easton (1952, 27) thinks that there are reasons to suppose that Bacon also gave courses on logic and grammar at the time. He therefore dates the Summa grammatica, the Sumulae dialectics and the Summa de sophismatibus et destructionibus to Bacon’s first Parisian period.  

About 1247, or perhaps as late as 1250, Bacon gave up his membership in the arts faculty at Paris and returned to Oxford. The evidences for such a return are his reported encounter with Adam Marsh (ca. 1200–1259), who lectured in Oxford between the years 1247 and 1250, and with Thomas of Wales, who lectured to the Franciscans at Oxford from 1240 to 1247 (Sharp, 1930, 115; Crowley, 1950, 27–29). Hackett (1997, 14) suggests the possibility that Bacon had met with Adam Marsh at Paris in 1245 or at a later date such as 1259.

The move to Oxford has been assumed to mark the turning point in Bacon’s interests. This turn involved an escape from the confines of the Aristotelian tradition and a dramatic broadening of his outlook in the direction of Robert Grosseteste’s philosophy and the contents of various Arabic sources. It supposedly marked the beginning of his campaign on behalf of mathematics and experimental science. According to Crowley (1950, 29) this turn occurred following Bacon’s acquaintance with Robert Grosseteste (1168–1252), after his return to Oxford. Easton (1952, 78), however, ascribes the turn in Bacon’s interests not to his return to England but to his reading of the pseudo-Aristotelian Secret of Secrets. He read this book toward the end of his life in Paris, and Easton (1952, 86) believes that “His whole later life and the emotional intensity with which he pursued it can be traced to the impact of this book”. When Bacon decided to undertake his study of science, he probably returned to England – a home to many of the older generation of scientists so highly praised by him – at once. His return was, according to Easton (1952, 87), the outcome of the turn, not its cause.

Right after returning to England, Bacon had sat down to write the glosses for the Secret of secrets. We also know that he heard Richard Rufus of Cornwall (d. after 1259) lecture on the Sentences at Oxford about the year 1250 (Compendium studii theologiae 4.86, 87).

There is a controversy among scholars concerning Bacon’s theological education. Crowley and Kuper (1950, 26; 1996, 30) believe that Bacon studied theology both in Paris while he was teaching and later on in Oxford under Adam Marsh. Crowley (1950, 27–28) adduces two references from the Opus tertium in which Bacon reports to have heard Adam Marsh. These references – so Crowley believes – indicate a relation of pupil and master. Crowley’s other rationale is that Bacon would not have taken upon himself to expose the vices in the theological teachings of his time had he never been an auditor in the faculty of theology.

Easton, Lindberg and Hackett (1952, 94; 1983, xix; 1997, 15), on the other hand, found no evidence that Bacon was lecturing or studying theology at Oxford. They all agree that Bacon never became a Master of Theology. Little (1914, 6, n. 1) notes that no thirteenth century manuscript refers to him as doctor or master of theology and that Bartholomew of Pisa (d. ca. 1401), who was very careful to distinguish between friars who were masters of theology and those who were not, always refers to him as frater, never as magister.  Easton (1952, 20-21) adds that no commentary on the Sentences by Bacon has been found, nor does he once quote from the Sentences. Since every student of theology at Paris and Oxford had to learn to comment on the Sentences of Peter Lombard as part of their training, such a commentary would surely exist had Bacon studied theology. Likewise, Bacon shows no familiarity with the writings of Alexander of Hales, Albertus Magnus and Thomas Aquinas (1225–1274) – the theologians of his time.

Another controversy involves the nature of Bacon’s relations with Robert Grosseteste. Steele and Kuper (1921, 128; 1996, 22) think Bacon was Grosseteste’s student in the 1230’s, that is, before he went to Paris. Little and Crowley (1917, 97; 1950, 29–31) argue that on returning to Oxford Bacon became Grosseteste’s disciple, perhaps even his assistant. Little even finds traces of Bacon’s influence in the treaties De impressione aeris, written by Grosseteste in 1249, and Crowley concurs. Lindberg (1983, xix) opposes such a contention, since from 1235 Grosseteste was no longer in Oxford. From that year on he was serving as the bishop of Lincoln, whose episcopal duties must have precluded heavy work in natural philosophy. Moreover, Bacon makes no claim to have met Grosseteste. Lindberg concludes that Bacon surely had felt Grosseteste’s influence, but only through the written word. Crombie (1953, 139) reaches a similar conclusion, stating that even though it is improbable that Bacon heard Grosseteste’s lectures at Oxford, he seems to have become a member of Grosseteste’s ‘circle’ by 1249 and there is no doubt he had access to his manuscripts. Hackett (1997, 11) thinks it likely that Bacon had seen Grosseteste. Bacon’s use of nam vidimus of Grosseteste implies that he had seen him and was clearly influenced by his example. Crombie (1953, 139) believes that Bacon could have visited Lincoln, especially in view of his interest in logic and the presence there of William of Sherwood (1190–1249), whom Bacon ranked as the best representative of the philosophia communis. Another possibility raised by Hackett (1997, 15) is that Bacon met both Grosseteste and Marsh in France when the two came to prepare for the Council of Lyon in January 1245.

Bacon joined the Franciscans in the mid-1250s or later (1257 is widely held to be the likely date), probably because he thought that it would somehow further his studies and his grand designs for the reform of Christendom (Lindberg, 1983, xx). A contributing factor could have been Grosseteste’s library, which he bequeathed to the Franciscan convent at Oxford (Easton, 1952, 91).

In many descriptions of Bacon’s course of life we find that the first ten years of his life as a Franciscan are characterized by severe illness, which kept him from study. Lindberg (1983, xxl), however, reminds us that: “Everything we know about this period of Bacon’s life comes from excuses offered to explain to the Pope why he had put so little on paper, and we must surely take these excuses with a grain of salt.”

It is not quite clear whether Bacon’s superiors and brothers supported or obstructed his studies, although the picture Bacon paints in his complaints to the pope is gloomy. He accuses them of burdening him with other duties and punishing him with isolation, hunger and “unspeakable violence” (Opus tertium 3, 15). Bacon’s trouble in the order could have had any of several causes, but the most likely was his apocalyptic leanings. Bacon had identified himself with the radical elements of his order, including Joachim of Fiore (ca. 1132–1202) and the “spirituals”, and thus opened himself to the same discipline to which they were subject (Easton, 1952, 126–37; Lindberg, 1983, xxiv). The Joachites and Spirituals were accused of provoking a schism within the order. Easton (1952, 137) claims that Bacon was “… steeped in the Joachitic and apocalyptic literature of his time, and is greatly influenced by it in his own work and his attitude to life, and he is especially impressed by the idea of the imminent approach of Antichrist.”

He is thought to have been displaced to the parent convent in Paris and ordered to undertake menial duties, without being allowed any contact with the outside world (Easton, 1952, 134–5; Clegg, 2003, 76).

The restrictions inflicted upon Bacon may have stemmed from the general chapter of Narbonne, which extended to the whole order and not have been directed specifically against him. The Chapter of Narbonne was issued in 1260 against Gerard of Borgo San Donnino (d. 1276/7), whose apocalyptic work Introduction to the Everlasting Gospel was declared heretical (Witzel, 1912).

Thorndike (1923, 627–628) offers a different picture of Bacon’s first years as a Franciscan. He thinks that the task of providing the Pope with a Magnum opus which Bacon had taken upon himself was beyond the powers of any one man. The fault of Bacon’s superiors, according to Thorndike, lay in not providing him with the expensive equipment he required for his experiments and continuing to require of him to perform the usual duties of a friar. Their attitude therefore, in Thorndike’s view, should not be described as one of persecution or hostility.

In those first years as a Franciscan (until 1266) Bacon wrote the De mirabilis potestate artis et naturae, and the De computo naturali (Little, 1914, 9–10). This was the period of his most intense occupation with optics, and in the late 1250s or the early 1260s he wrote the De multiplicatione specierum – his most fully thought-out piece, which he himself also thought was his best – and the De speculis comburentibus (Easton, 1952, 104; Lindberg, 1983, xxxiil).

Bacon presumably had sent out a steady stream of requests for external sponsors, asking permission to return to Oxford. One of the people he wrote to in 1263–4 was the cardinal-bishop of Sabina, Guy de Foulques (Lindberg, 1983, xxii; Clegg, 2003, 92). The Cardinal responded by asking Bacon to send him his writings, but Bacon had nothing yet to send. In February 1265 Guy de Foulques was elected Pope as Clement IV, and Bacon then sent him another letter, which was partly an apology that nothing had yet been done and partly a request for financial aid with his scientific study (Easton, 1953, 146; Hackett, 1997, 17; Clegg, 2003, 95). In June 1266 the Pope replied, directing Bacon to send the work previously requested “notwithstanding any prohibitions of his order”, but to keep the commission a secret (Steele, 1921, 140; Easton, 1952, 148; Hackett, 1997, 17). This statement released Bacon from the censorship imposed by the Chapter of Narbonne, which forbade issuing books outside the Order, and even their composition, without the license of the Minister-General of the Franciscan Order. However, it did not provide him with any funds, and so left him empty-handed before an extremely demanding task. (Lindberg, 1983, xxiii; Clegg, 2003, 80).

Bacon replied with three works: the Opus majus, Opus minus and Opus tertium. The Opus majus, along with the De multiplicatione specierum, was sent to the Pope in 1267, followed by the Opus minus and possibly by some works on astrology and alchemy, perhaps even the De speculum comburentibus (Crombie and North, 1970, 378; Lindberg, 1983, xxv; Hackett, 1997, 22). There is considerable disagreement over the order and manner of writing the three works and whether the Opus tertium was ever sent. Thorndike (1923, 624) thinks that Bacon prepared the Opus minus and the Opus tertium in case the Opus majus did not arrive or the Pope found it too long to read. Mandonnet (1913), on the other hand, thinks that the Opus minus and Opus tertium were composed before or at the same time with the Opus majus and that they were eventually not sent at all but incorporated instead in the major work. Crowley (1950, 43–46) strongly objects to this theoretical sequence of events; he thinks the Opus tertium was written only after the Opus majus and the Opus minus had been sent to the pope. To support this chronology he relies in this contention on Bacon’s explicit statement at the beginning of the Opus tertium that he had already sent two kinds of writings to the Pope: one, the major work, divided into four parts because of its size; the other, a kind of compendium and supplement to the first (Opus tertium 1, 1965, 3). He further alludes to the innumerable expressions in the latter work implying that the Opus majus was no longer in his possession: for example, Bacon cannot recall how many reasons he had given for the necessity of studying languages, nor can he remember in what order he had given them (Opus tertium 11, 1965, 38). In some places, Bacon seems to be correcting in the Opus tertium mistakes that have crept to the Opus majus (For example, Opus tertium 67, 273–274). Crowley (1950, 48) believes the three works were written within eighteen months, that is, Bacon had begun writing only upon receiving the papal mandate.

Easton (1953, 151–54) agrees with Thorndike and Crowley that most of the Opus tertium consists of afterthoughts to the Opus majus and it was written after the latter work’s completion. Furthermore, he believes it was never sent to the Pope, nor ever completed, since the Pope had died in the meantime. He suggests the following sequence: three years after the first mandate, Bacon had completed the Opus majus and sent it off to the copyists. This would take some time, for the work was of considerable length. Meanwhile Bacon began to think of all the things he had omitted from the great work; so he started to work at once on another text. To ensure that this new work would be of some use if the major work were lost, Bacon gave in it the digest of the most important material in the Opus majus. This new work is the Opus minus. Having written it, Bacon cannot bear not to send it; so off it goes, too, to the copyists to be put into good script. Now Bacon begins what should have been an introduction to both works, and in the Opus tertium he gives a long and moving account of his “impediments”. Yet along with that he states that he has “gained the remedies for his former impediments” and is now able to add some necessary things which he could not put in before (Opus tertium 1, 5). Easton (1952, 164) assumes that at this point, when financial troubles were threatening to overwhelm him, he finally gave up the attempt to dispatch the works secretly and turned to his superiors for support. When the Opus majus returned from the copyists, Bacon was no longer satisfied with it. He then revised it by inserting extracts from the Opus tertium. Later he wrote a brief introduction, including a recommendation for his student John, who was to carry the works to the Pope; this letter is the Gasquet fragment (Easton, 1952, 165–166). Hackett (2018) suggests that the abovementioned John was no other than Peter John Olivi (1248–1298). Once the works were on their way, probably early in 1268, Bacon started to work once more on the Opus tertium, many passages of which are superior to the similar parts of the Opus majus. However, it was never finished or sent. The Pope died in the same year, and his successor was not elected until 1271; so Bacon received no answer, and no result had followed from his writings (Steele, 1921, 141; Easton, 1952, 166).

Tradition has it that after completing the three works, Bacon returned to England. Little (1914, 20) argues that the fact that the glosses to the Secret of secrets were written in England is an evidence for Bacon’s return. Easton (1952, 187), however, thinks the glosses were written long before the introduction to the same work; so the introduction itself, written much later, cannot serve as definite evidence. On the other hand, he believes that the fact that Bacon’s manuscripts have been found scattered through English libraries, along with the many stories and legends told about him around England, could serve as evidence for such a return. Steele (1921, 141) too notes the many legends of how Bacon constructed magical mirrors and perspective glasses. Easton (1952, 188) further suggests that if Bacon had indeed made peace with his superiors in Paris –  by showing them that he was not writing anything subversive, and if indeed the Pope’s mandate had increased his prestige and importance within the order, then the reasons for keeping him in France would be at an end.

Most scholars agree that perhaps at this time (the late 1260s and early 1270s) Bacon wrote his Communia naturalium and Communia mathematica, mature expressions of many of his theories (Easton, 1952, 111, 158, 186; Crombie and North, 1970, 378; Lindberg, 1983, xxv; Hackett, 1997, 22). Crowley (1950, 64–5) places these two works after the Compendium studii philosophiae from 1271-2 and sets the Communica mathematica before the Comminia naturalium. Hackett (1997b, 284–285) argues that the fourth part of the first book of the Communia naturalium is in fact a section of the Opus tertium. The Communia naturalium may have been composed over a long period of time and was only revised and enlarged after Bacon completed his works for the Pope (Easton, 1952, 42(. Both Little (1914, 11) and Sharp (1930, 116) believe that it was the Communia naturalium that Bacon had begun writing upon receiving the first request from Guy de Foulques. It was meant to present an exhaustive account of the various branches of knowledge; but when Bacon realized the enormity of the task, he laid it aside in January 1267 and turned to the less ambitious introduction which he named Opus majus. This is why Bacon sometimes calls the latter Tractatus praeambulus, thereby distinguishing it from the great systematic work on all the sciences he had hoped to write (Little, 1914, 11–12). Little and Sharp therefore identify the Communia with the scriptum principale of Crowley.

Now comes the period – a period beginning, in fact with the Opus majus – of Bacon’s intense occupation with language. The Greek and Hebrew grammars belong to the phase immediately following the Opus majus (Easton, 1952, 186).

These were followed in 1271 or 1272 by the polemical Compendium studii philosophiae, in which Bacon abuses the Franciscan and Dominican orders for their educational practices. This work, which was written within the turbulent period of a struggle between the seculars and the orders, accompanied by a rivalry between the two orders, shows Bacon’s despair at the condition of society (Easton, 1952, 189–190). We know the approximate date of its composition, because Bacon refers in it to the interregnum preceding the election of Gregory X in September 1271 (Compendium studii philosophiae 1, 399).

A chronicle from about 1370 reports that Bacon was condemned and imprisoned by his order for “certain suspected novelties”. The chronicle further tells us that Bacon’s works and doctrines were to be avoided by all, since the order had rejected them (Chronica XXIV Generalium Ordinis Minorum. Reprinted in Crowley, 1950, 67). Although this account was written a hundred years after the event and identifies Bacon as a “master of sacred theology”, which he probably never was, most recent biographers accept it as reliable (Lindberg, 1983, xxv-xxvi; Crowley, 1950, 67–72; Easton, 1952,  192–202; Crombie and North, 1970, 378). Crowley (1950, 69–71) dates the event to between 1277 and 1279 and notes that the imprisonment cannot have been too rigorous nor of very long duration. He rather thinks of some form of “correction” imposed on Bacon. We know that his works were condemned and that he himself was supposedly confined to the Paris convent, perhaps until 1292, by Jerome of Ascoli (d. 1292), the Franciscan minister-general, who later became Pope Nicholas IV (Sharp, 1930, 117).

The reason for this condemnation is unknown. Little (1914, 26) links it with a meeting in Paris in 1277 between John of Vercelli (1205–1283), the Dominican master-general, and Jerome of Ascoli, a meeting whose purpose was to device measures against the quarrels between the two orders. Among other things, they have decided to decree that the friars of both orders should abstain from mutual detractions. In the Compendium studii philosophiae Bacon had clearly violated that decree.

Bridges (1914, 29–32) and Easton (Easton, 1952, 191) attributes this imprisonment to repercussions resulting from the Compendium studii philosophiae. They believe that whether it was published or not, Bacon’s views were well known to his fellow-friars. The Compendium was a political tract, likely to give offence both to the more conservative members of his own order and to the Dominicans. It was soaked with the spirit of the prophetic literature of the day, favoured by the spirituals, at a time when the most urgent problem the Franciscan authorities had to deal with of the schism within the order (Easton, 1952, 197). In the same spirit, Sharp (1930, 117) ascribes the condemnation to Bacon’s “obnoxious attack on his contemporaries, Franciscans as well as Dominicans and seculars.” Her examples of such attacks are all taken from the Opus tertium and the Compendium. Add all this to Bacon’s general attitude toward authority, and there is no need to find offending doctrines in his writings. More than any of his theories, it was his personality that was condemned. “Suspected novelties” then becomes then a convenient blanket term for all that (Easton, 1952, 200).  

Sidelko (1996, 70), however, suggests a different motive for the condemnation. He argues that the novelties referred to by the chronicle are certain points in Bacon’s astrological doctrine concerning the influence of the conjunction of Jupiter and Saturn on the human nature of Christ at his birth and the advent of Christianity. Bacon derived his ideas almost exclusively from pagan and occult sources, the same sources which the condemnation of 1277 and the resolution of the Spiritual Franciscan controversy were meant to eradicate (Sidelko, 1996, 80–81). Bridges (1914, 32) also ascribes the condemnation to this reliance on Pagan authorities. He notes the high esteem that Bacon gave to Seneca (ca. 4 B.C.–65 A.D.) and the Stoics in moral matters, as well as the high ethical value that he set on the Muslim writers al-Farabi (ca. 872–950/1), Avicenna (980–1037) and al-Gazali (1058–1111). Crombie and North (1970, 378) concur, assuming that Bacon’s condemnation was related to the censorship of heretical Averroist propositions by Tempier in 1277. Crowley (1950, 70) reminds us that the text of the chronicle refers not to Stephen Tempier as Bacon’s jailer but to Bacon’s superiors within the Franciscan order. He suggests that Tempier’s action encouraged the theologians at the Franciscan convent in Paris to take steps to ensure the purity of doctrine within the Order.

In 1292, at a chapter of the order held in Paris, just after Jerome of Ascoli’s death, certain prisoners condemned in 1277 were set free. Some writers (for example, Bridges, 1914, 35) think Bacon may have been one of them. Others (Easton, 1952, 201–202; Crowley, 1950, 71) think his house arrest was of a much shorter duration.

The last evidence of Bacon’s life is that in 1292 he wrote the Compendium studii theologie, which he left unfinished. This was a grammatical work, repeating many of the themes and ideas that had appeared long before in his De signis. It is reasonable to assume that he died in 1292 or soon thereafter (Easton, 1952, 205; Lindberg, 1983, xxvl).


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