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] [Sidenote: How long had Henry I been reigning?]