_Son._ It is evident that whoever wishes to become informed on such matters as those which you have now discussed must first try to determine what is most worth learning and afterwards to keep in mind all that he has heard. But in your discussion just recently you mentioned several things the nature of which I do not understand, though I have reflected upon your statements, namely, the lights of the sky and the movements of the ocean. Moreover, you urged me to learn these things and stated that there is knowledge in learning them. But I cannot comprehend them unless I shall hear them explained; and I know of no other wise master with so kind a will to teach me these matters as yourself. Therefore, with your permission, I will ask you to continue this discussion, so that I may become somewhat better informed on these subjects: how the lights of the sky and the course of the heavenly bodies wax and wane; how the time of the day is told and the hours are grouped; but especially how the ocean moves and what causes its restlessness. For sometimes the ocean appears so blithe and cheerful that one would like to sport with it through an entire season; but soon it displays such fierce wrath and ill-nature that the life and property of those who have anything to do with it are endangered. Now I have thought that, although the sun completes its course according to an established law, that fact cannot produce the unquiet of the sea. If you are disposed to explain these things further, I shall listen gladly and attentively.