is entitled in a Munich Ms. "Contra Mag. Sogerum," but chiefly by an examination of the extant works of Siger, in particular the De anima intellectiva, to which he is convinced Thomas Aquinas's treatise above mentioned is a reply. And in fact, whether Aquinas's work is directed specially against Siger or not, it seems quite evident from the seventh chapter of Siger's De anima intellectiva that he inclines to the belief in the unity of the human intellect. Whether his view is identical in all details with that of Averroes is irrelevant to the matter in question. Siger does not enter into all the particulars of the knotty problem, and he may reserve a certain degree of independent thinking, and yet belong to the Averroistic school, as it was then named. There is at any rate no doubt that all indications point to Mandonnet's view as the true one.
There was also a disagreement about the time of Siger's death, Baeumker maintaining, on grounds in themselves plausible, that he died in the years 1290-91, whereas Mandonnet on the strength of a letter of John Peckham, Archbishop of Canterbury, puts his death before 1284. This letter is dated November 10, 1284, and though it does not name Siger or Boethius of Dacia, the reference to the "two chief defenders" of the heretical doctrine (the unity of forms), "who ended their days miserably on the other side of the Alps, though not having originated in those parts," is, from what we know of the situation, not at all obscure or ambiguous. Siger and Boethius of Dacia are the two persons meant, and Peckham believed them dead when he wrote his letter in 1284.
Since the publication of Mandonnet's first edition in 1889, a number of things have happened. A new text was discovered containing a reference to Siger to the effect that, being unable to remain in Paris on account of his advocacy of heretical opinions, he went to Rome and there at the Roman Curia he was after a little while stabbed by his secretary in a fit of madness ("a clerico suo quasi dementi perfossus periit"). This important document enabled Baeumker (Archiv für Geschichte der Philosophie, Vol. XIII, 1900, pp. 73 ff.) to identify with certainty the Siger of Dante, i.e., our Siger, with the Siger of the Italian poem Il fiore who, we know, died in Orvieto. Of the three available periods of the Papal visits to Orvieto, Baeumker now decided with Mandonnet for the first, under Martin IV, 1281-84, an d since we know that Siger had left Paris in 1277, and the text above referred to puts his death shortly after, 1282 is the date Baeumker finally decided upon. In 1907 Bruckmüller presented a dissertation to the University of
