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. [Sidenote: Some apparent indications that the _De eodem et diverso_ was written after the _Natural Questions_.]