His Holiness Pope Pius XI, proclaiming Albertus Magnus a Saint and a Doctor of the Church, said of him, that he knew everything that was to be known. And indeed his outstanding characteristic was the universality of his learning. In his writings he covered the whole field of knowledge, and he was as great in philosophy and theology as in meteorology, astronomy, geography, mineralogy, chemistry, physics, zoology, botany, physiology, and in the other natural sciences. It is, therefore, not surprising that on account of the eminence and universality of his learning he was known among his contemporaries, as he has been known ever since, as the Doctor Universalis, and as Magnus, ‘ the Great.’
His complete works were printed for the first time in 1651 at Lyons, in twenty-one volumes in folio, and again at Paris in 1890-98, in thirty-eight volumes in quarto. Besides these, many authentic writings are still in manuscript in the libraries and archives of various cities of Europe. Scholars consider that, if published, they would fill at least ten folio volumes.
But it is impossible to appreciate the imposing personality of the Doctor Universalis without having a thorough knowledge of his writings, and that is an exceedingly difficult task without a sure guidance, as all those who are acquainted with mediaeval studies well know. At the moment this difficulty is the greater owing to the lack of a critical edition of his works, and to the fact that some of those published are either dubious or clearly spurious.