The Fourth Book of Cornelius Agrippa was much too informal, and left too much to the discretion of the operator, to be satisfactory for a science so exact as that of Ceremonial Magic. A form of procedure which bequeathed nothing to the imagination and asked no other skill than the patient exactitude of the rule of thumb was necessary to the weakness of the ordinary sorcerer. The Heptameron, or Magical Elements ascribed to Peter de Abano is an attempt to supply the want and to offer to the neophyte a complete wizard's cabinet. Cornelius Agrippa, says the introduction, which might, ex hypothesi, be that of a later hand, seems to have written for the learned, for the well-experienced in this art; he does not treat specially of the ceremonies, but mentions them in a general way. Those who have not "tasted magical superstitions" may here find them ready to their hand. "In brief, in this book are kept the principles of magical conveyances." It may be conceded at once that the undertaking is scrupulously fulfilled; what the operator must do and how he should perform it, so as to "draw spirits into discourse," are matters set forth so plainly that the wayfaring man need not err therein. Assuming the sacerdotal office of the operator, or a priest for an accomplice, it is all so simple that failure could not well be ascribed to a blunder on his part. It would be invidious to suppose that the Heptameron is more authentic as regards its attribution than the work to which it is professedly a sequel; its real authorship is involved in much the same kind of obscurity as that of pseudo-Agrippa. There are several grave reasons why the pupil of Trithemius should not have written the spurious Fourth Book, but Peter of Abano is not an unlikely personage to connect with the Magical Peter of Abano, a town in the vicinity of Padua, was born in 1250 and was a learned physician of his period, who attempted to conciliate the different medical systems and is supposed to have been the first European who quoted Averroes. He established himself at Paris, but at the instigation of jealous professional brethren he was accused of heresy and fled to his native place. At Padua a chair of medicine was created for him, but the accusation followed its victim; by some he was charged with denying the existence of demons, by others with obtaining his knowledge from seven imps whom he kept in a bottle. However this may be, the Inquisition instituted a process, but the designed sufferer was delivered by death--as some say, on the eve of his execution. The intervention infuriated the Tribunal, though the testament left behind him by Peter of Abano affirmed his belief in the orthodox faith. The magistrates of the city were ordered, on pain of excommunication, to exhume his body, but it was removed by a faithful servant and buried secretly in another church. The Inquisition clamoured for the punishment of the offender but
90:1 A sequel, moreover, which contains several direct references, as, for example: "But after what manner they appear has been described already in the former book of magical ceremonies"--The Conjuration of the Lord's Day. This recurs with slight variations throughout the Heptameron. It may be advisable to add that Agrippa was of the sixteenth century.