Book,  Paragraph

 1   I,  3 |       As a preliminary we must explain in what sense we are using
 2   I,  8 |       8~We must now proceed to explain why there cannot be more
 3   I,  8 |    intermediate itself we will explain later on.~We have now said
 4   I,  9 |        First, however, we must explain what we mean by "heaven"
 5  II,  3 |       granted and try later to explain.) these four elements generation
 6  II,  9 |      not hear this music, they explain this by saying that the
 7  II,  13|        generate the heavens to explain why the earth came together
 8  II,  13|        so, it still remains to explain why fire stays at the extremities.
 9 III,  2 |      infinite, may be asked to explain the manner of their motion
10 III,  3 |      will be plain if we first explain what kind of substance an
11 III,  8 |     not to others, they should explain the difference, instead
12 III,  8 |         however, do attempt to explain this power, and they contradict
13 III,  8 |      inquiry will enable us to explain the differences of each
14  IV,  1 |  relative. I mean, they do not explain what the heavy is or what
15  IV,  2 |    parts, which must therefore explain any distinction of relatively
16  IV,  2 | attempted this, have failed to explain why there are bodies which
17  IV,  2 |        heavy; they had only to explain why these two things are