CHAPTER XXVI
GERBERT

Life. Gerbert was born in Aquitaine, about the middle of the tenth century. He became a monk at the monastery of Aurillac, and there, according to Richer, a contemporary and disciple, he met the count of Barcelona, with whom he went to Spain in order to study mathematics and the physical sciences. Thence, at the request of Otho II, he went to Rome. From Rome he went back to France, and in 991 became archbishop of Rheims. In 997 he was transferred to the see of Ravenna. In 999 he became pope, taking the name of Sylvester II. He lived until 1003.

Gerbert is credited with being the first to introduce the Arabic numerals into Christian Europe.^{1} He is said also to have constructed clocks and other mechanical contrivances. It was probably his acquaintance with astronomy and his success as a mechanical inventor that earned for him the reputation of magician. The legends collected and published by Benno in the eleventh century represent Gerbert as in league with the devil. The less ignorant, however, among Gerbert's contemporaries acknowledged him to be a pious monk and a man of extraordinary learning.

Sources. Migne, in his Patrologia Latina, Vol. CXXXIX, publishes the following works of Gerbert: Libellus de Numerorum Divisione; De Geometria; De Sphaerae Constrictione; and Libellus de Rationali et Ratione Uti. Gerbert's letters were published by Masson in 611, and republished by Duchesne in 1636. Richer's Histories, which throw so much light on the life and character of Gerbert as well as on some important points of his doctrine, were first published by Pertz in the Monumenta Germaniae.^{2} To these sources must be added a poem by Adalbero, published in the Patrologia Latina, Vol. CXLI, and a letter of Leo, abbot and papal legate, which is found in Vol. CXXXIX of the Patrologia Latina. The work De Corpore et Sanguine Domini, attributed to Gerbert by Pertz and others, is of doubtful authenticity.

An excellent monograph of the life and teaching of Gerbert is M. Picavet's Gerbert, un pape philosophe (Paris, 1897). cf. Catholic University Bulletin, Vol. IV, pp. 295 ff. (July, 1898).

DOCTRINES

Gerbert as a Teacher. In the midst of the wars and other external circumstances which combined to bring about a state of almost universal neglect of learning, Gerbert revived at the school of Rheims the best traditions of the early days of the Scholastic movement. He taught the dialectic of Aristotle, using a translation of the Categoriae in addition to the Isagoge of Porphyry and the commentaries of Boethius. He also taught rhetoric, employing, it is said, a mechanical contrivance in order to express the different combinations of figures of speech, and in one of his letters he speaks of a sphere by means of which he illustrated "the horizon and the beauties of the heavens." His work De Divisione Numerorum shows that he occupied himself with the task of popularizing the theory of multiplication.

Gerbert as a Philosopher. 1. Richer, a contemporary and disciple of Gerbert, gives a most interesting description of an encounter which took place at Ravenna in the year 980 between Gerbert, master of the schools at Rheims, and Otric, the most famous of the masters of the German schools. The Emperor, Otho II, and many distinguished prelates lent solemnity to the scene by their presence. Gerbert opened the discussion by defining philosophy as "divinarum et humanarum rerum comprehensio veritatis," thus identifying philosophy with knowledge. Then he proceeded to divide philosophy into theoretical and practical. He further distinguished physics, mathematics, and theology (theologia intellectibilis) as parts of theoretical philosophy, and moral (dispensativa), economic (distributiva), and political (civilis) philosophy as subdivisions of practical philosophy. After a discussion as to the place which physiology and philology should occupy in this classification of philosophical sciences, the disputants passed on to the question, "What is the aim of philosophy?" Gerbert answered that the final cause of philosophical study is a knowledge of things human and divine, in other words, that philosophy is, so to speak, its own reward. At this point the argument veered round to the Platonic account of the cause of the world. Next the disputants took up the discussion of the cause of shadows, and when, at the close of the day's debate, the Emperor put an end to the disputation, the question under discussion was whether mortal is to be subordinate to rational or vice versa, or, as we should say, whether the term mortal or the term rational has the greater extension.

2. The Libellus de Rationali et Ratione Uti, addressed to the Emperor, takes up the problem of predication at the point where the oral discussion had been interrupted, and inquires whether ratione uti should be predicated of rationale. It was a principle admitted by dialecticians that the predicate should possess wider extension than the subject; since, therefore, reasonable is of wider extension than using reason, is not Porphyry wrong when he says that using reason may be predicated of reasonable? Gerbert approaches the problem by stating the objections which may be urged from three sources, namely, from the relation of power to act, from the relation of the accidental to the substantial, and from the relation of the higher concept to the lower. He then proceeds to elucidate these notions, determining the nature of act and power, thus using the objections in order to throw light on the problem, so that when he comes to the thesis that ratione uti may be predicated of rationale he has no difficulty in proving his proposition by the use of the concepts, act, power, etc., on which the objections rested.

This little treatise is, therefore, the first sample of the use of the Scholastic method, which, a century later, was employed in Abelard's Sic et Non, and was perfected by the philosophers of the thirteenth century. It is by reason of its method rather than of its contents that the treatise occupies so important a place in the history of Scholastic philosophy.

3. Adalbero, who was at one time a disciple of Gerbert at Rheims, and who died in 1030, mentions in a poem addressed to Robert II of France certain theories concerning the origin of the universe and adds, "I found these things, being not unmindful of what I have heard." If the theories in question are those of Gerbert, and it is natural to suppose that Adalbero is speaking of his former teacher, it is evident that our philosopher did not confine his philosophical teaching to the problems of dialectic, but that he carried his inquiries into the region of cosmogony and anthropology.

4. The letter of Leo, the papal legate appointed to inquire into the rival claims of Gerbert and Arnoulf to the see of Rheims, bears further testimony to the many-sidedness of Gerbert's teaching. It implies that Gerbert included in his curriculum the study of nature and, perhaps, the study of animal life. This is all the more remarkable when we recall that Gerbert belonged to an age to which Aristotle's treatises on the natural sciences were completely unknown.

Historical Position. Gerbert must have exercised considerable influence on his own generation. The very grotesqueness of the notions which the superstitious entertained concerning him is proof of his preeminence. He is in the tenth century what Erigena was in the ninth and what Abelard will be in the twelfth. His influence, however, was exercised by his oral teaching rather than by his written works. To his disciples, and to the masters who succeeded him in the schools in France, the dialectical movement which was continued by Roscelin, Abelard, and St. Anselm, and by them transmitted to the thirteenth century, owes a larger debt than can be accurately determined.

{1} On the use of Arabic numerals by Boethius, cf. Lavisse Ct Rambaud, Histoire générale du IV^e siècle à nos jours (Paris, 1896), Vol. I, p. 785, n.

{2} Richer's Histories are published by Migne (juxta Pertz), Patr. Lat., Vol. CXXXVIII, coIl. 17-170. For bibliography cf. Potthast, Wegweiser durch die Geschichtswerke des Europäischen Mittelalters, p. 501.