In the Natural Questions, on the other hand, he returns to England after seven years, instead of a single year, of separation from his nephew, after a visit to the principality of Antioch,[111] and after a considerable period of study among the Saracens or Arabs. It is rather natural, however, to conclude that the same absence abroad is referred to in both treatises, and that Adelard wrote De eodem et diverso to his nephew after he had been absent a year, while the Natural Questions was composed after his return at the end of seven years. Thus six years would separate the two treatises. But the Natural Questions depicts a different last parting of uncle and nephew from that of De eodem et diverso. It does not allude to their having been together in Tours seven years ago, but reminds the nephew how, when his uncle took leave of him and his other pupils at Laon seven years since, it was agreed between them that while Adelard investigated Arabian learning, his nephew should continue his studies in Gaul.[112] In the De eodem et diverso, on the contrary, neither Laon nor the Arabs nor any such agreement between uncle and nephew is mentioned. Rather, the uncle seems to have at first kept secret the motives for his crossing the Alps. It therefore may be that Adelard had returned from Sicily to Gaul and had taught at Laon for a short time before setting out on a longer period of travel in quest of Arabian science. This would agree well enough with his allusion to his nephew in the De eodem et diverso as “still a boy,”[113] and the statement in the Natural Questions that his nephew was “little more than a boy”[114] when he parted from him seven years before. In this case the Natural Questions would have been written more than seven years after the De eodem et diverso. This is, I think, the most tenable and plausible hypothesis.

Some apparent indications that the De eodem et diverso was written after the Natural Questions.

There are, it is true, one or two circumstances which might be taken to indicate that the De eodem et diverso was written after the Questiones naturales. In the sole manuscript of the De eodem thus far known[115] it follows that treatise, and its title Of the same and different might be taken as a continuation with variations of the general line of thought of the other treatise. But it is perhaps just because some copyist has so interpreted its title that it is put after the Natural Questions in this manuscript. At any rate in the text itself Adelard gives another explanation of its title, stating that it has reference to the allegorical figures, Philosophia and Philocosmia, who address him in his vision, and who, he says, are designated as eadem and diversa “by the prince of philosophers,”—an allusion perhaps to some of Aristotle’s pronouns.[116] Another curious circumstance is that the problem, How far would a stone of great weight fall, if dropped in a hole extending through the earth at the center? occurs in both the De eodem and Natural Questions.[117] In the latter the nephew puts the query to his uncle: in the former a Grecian philosopher whom Adelard has been questioning concerning the properties of the magnet in attracting iron, in his turn asks Adelard this question. Now in the Natural Questions Adelard’s answer is given, as if the nephew had never heard it before, but in the De eodem et diverso it is simply stated that the Greek “listened to my explanation of this,” as if the nephew had already heard the explanation from his uncle.[118]

How long had Henry I been reigning?

In opening the Natural Questions Adelard states that Henry I was reigning when he returned to England recently. This statement, in Professor Haskins’ opinion, “would seem to imply that he originally left England for his studies in France before Henry’s accession.” I am not quite sure that this inference follows, but if it does, may one not go a step further and argue that Henry I had come to the throne since Adelard parted from his nephew at Laon to investigate the learning of the Arabs? Had Henry become king of England while Adelard was still studying or teaching in northern Gaul, he would almost certainly have heard of it, and it would have been no news to him on his return from his studies among the Arabs. If we accept this view, Adelard’s return to England would be not later than 1107. But it could scarcely be earlier, if he wrote and dedicated the Natural Questions promptly after his arrival, of which he speaks as a recent event in that work, since the dedicatee did not become Bishop of Bayeux until 1107. And if the De eodem et diverso was written more than seven years before the Natural Questions, we should have to date it back into the eleventh century, which would perhaps be too early for its dedication to William, bishop of Syracuse. And to put these two works so early is to leave a gap between them and the other known dates of Adelard’s career, 1126, 1130, and 1142-1146, and make the period of his literary productivity quite a long one. He would have been quite a graybeard when he wrote on the astrolabe for the juvenile Henry Plantagenet. On the whole, therefore, I am inclined to think that Henry I had been reigning for some time when Adelard wrote the Natural Questions.

[104] Haskins (1911) pp. 492-3.

[105] It is true that after 1109, “The queen herself, who had for a time accompanied the movements of her husband, now resided mostly at Westminster” (G. B. Adams in Hunt and Poole, Political History of England, II, 151), so that Adelard would not have had many opportunities to play before her in the English possessions across the channel after that date.

[106] De eodem et diverso, pp. 25-6, Philosophy addresses Adelard, “... cum praeterito anno in eadem musica Gallicis studiis totus sudares adessetque in serotino tempore magister artis una cum discipulis cum eorum reginaeque rogatu citharam tangeres.”

[107] P. 3, line 16, “Quoniam autem in epistola hac ...”; line 25, “Hanc autem epistolam ‘De eodem et diverso’ intitulavi”; p. 34, line 7, “Vale; et utrum recte disputaverim, tecum dijudica.”

[108] P. 3, line 9, “Nam et ego, cum idem metuens iniustae cuidam nepotis mei accusationi rescribere vererer, in hanc demum sententiam animum compuli, ut reprehensionis metum patienter ferrem, accusationi iniustae pro posse meo responderem.”