In the province of philosophy, Gerbert’s labours extended little beyond formal logic, philosophy’s instrument. He could do no more than understand and apply as much of Boëthius’s rendering of the Aristotelian _Organon_ as he was acquainted with. Yet he appears to have used more of the Boëthian writings than any man before him, or for a hundred and fifty years after his death. Richer gives the list. Beyond this evidence, curious testimony is borne to the nature of Gerbert’s dialectic by Richer’s account of a notable debate. The year was 980, when the fame of the brilliant young _scholasticus_ of Rheims had spread through Gaul and penetrated Germany. A certain master of repute at Magdeburg, named Otric, sent one of his pupils to report on Gerbert’s teaching, and especially as to his method of laying out the divisions of philosophy as “the science of things divine and human.” The pupil returned with notes of Gerbert’s classification, in which, by error or intention, it was made to appear that he subordinated physics to mathematics, as species to genus, whereas, in truth, he made them of equal rank. Otric thought to catch him tripping, and so managed that a disputation was held between them at a time when Adalberon and Gerbert were in Italy with the Emperor Otto II. It took place in Ravenna. The emperor, then nineteen years of age, presided, there being present many masters and dignitaries of the Church. Holding in his hand a tablet of Gerbert’s alleged division of the sciences, His Majesty opened the debate: “Meditation and discussion, as I think, make for the betterment of human knowledge, and questions from the wise rouse our thoughtfulness. Thus knowledge of things is drawn forth by the learned, or discovered by them and committed to books, which remain to our great good. We also may be incited by certain objects which draw the mind to a surer understanding. Observe now, that I am turning over this tablet inscribed with the divisions of philosophy. Let all consider it carefully, and each say what he thinks. If it be complete, let it be confirmed by your approbation. If imperfect, let it be rejected or corrected.