Book, Paragraph

 1  IV, 8 |    e.g. fire upward and earth downward and towards the middle of
 2   V, 5 |    have upward locomotion and downward locomotion, which are contrary
 3   V, 6 |      respectively contrary to downward motion and rest below, these
 4   V, 6 | belongs naturally to fire and downward to earth, i.e. the locomotions
 5   V, 6 |    motions, the upward or the downward, will be natural, the other
 6   V, 6 |       motion and an unnatural downward motion: is it, then, this
 7   V, 6 |      it, then, this unnatural downward motion or is it the natural
 8   V, 6 |   motion or is it the natural downward motion of earth that is
 9   V, 6 |    natural is contrary to the downward motion of fire as being
10 VIII, 4|   motion of earthy things and downward motion of fire are unnatural.
11 VIII, 4|     also possess the power of downward locomotion. Moreover if
12 VIII, 4| upward motion of fire and the downward motion of earth are derived.
13 VIII, 4|       upward, the latter by a downward, tendency. As we have said,
14 VIII, 8|     motion is the contrary of downward motion, forward motion of