Book,  Paragraph

 1   I,  2 |      motion, while the upward and downward movements are in a straight
 2   I,  2 |        away from the centre, and "downward" motion towards it. All
 3   I,  2 |          contrary; and upward and downward motion are the contraries
 4   I,  2 |       will be fire or air, and if downward, water or earth. Further,
 5   I,  2 |        and earthy bodies straight downward towards the centre-since
 6   I,  2 |          case with the upward and downward movements, which are natural
 7   I,  2 |        just as unnatural to it as downward movement; for any one can
 8   I,  3 |           of all things that move downward, and the lightest that which
 9   I,  3 |           that case, if it is the downward movement which is unnatural,
10   I,  3 |           which is unnatural, the downward will be natural. For we
11   I,  3 |   violently aside in an upward or downward direction. For neither naturally
12   I,  6 |      infinite. For the upward and downward motions are contraries and
13   I,  6 |          to the bottom starts its downward motion, it cannot go farther
14   I,  7 |          neither that which moves downward, nor, by the same reasoning,
15   I,  8 |          For as superior speed in downward movement implies superior
16   I,  8 |     slower would be the upward or downward movement; but the fact is
17  II,  1 |       enough to overpower its own downward tendency, and thus has been
18  II,  13|          and it will continue its downward movement with nothing to
19  II,  13|    prevented from moving with the downward movement which is natural
20  II,  13|          this be upward motion or downward or what? It must have some
21  II,  13|         motion; and if upward and downward motion are alike to it,
22  II,  13|        could air below it prevent downward movement. For the same cause
23  II,  13|   indifference. Motion upward and downward and sideways were all, they
24  II,  14|           Only they attribute the downward movement to constraint,
25 III,  2 |     movement which is natural, as downward movement is to a stone,
26 III,  2 |          and qua heavy produces a downward motion. In either case the
27 III,  5 |       many things move the faster downward. For these reasons, then,
28  IV,  1 |        which is towards it I call downward movement. (The view, urged
29  IV,  1 | absolutely heavy that which moves downward or to the centre. By lighter
30  IV,  1 |          the speed of its natural downward movement.~
31  IV,  2 |       reverse movement from above downward, the small mass will move
32  IV,  2 |       some move upward and others downward. The fact, again, that the
33  IV,  2 |          which nevertheless moves downward as constantly as the other
34  IV,  2 |        which have weight and move downward, while, on the other hand,
35  IV,  2 |          of the less, just as the downward movement of a mass of gold
36  IV,  2 |           and of a plenum to move downward, and therefore each causes
37  IV,  3 |       naturally upward and others downward, while others again move
38  IV,  3 |        again move both upward and downward. After that we will inquire
39  IV,  3 |         which produces upward and downward movement is that which produces
40  IV,  3 |        things that move upward or downward is the extremity and the
41  IV,  3 |       fire moves upward and earth downward is the same as to ask why
42  IV,  3 |        goes upward, a heavy thing downward. The only difference is
43  IV,  4 |           moves upward, and earth downward; and, if the quantity is
44  IV,  4 |           own nature always moves downward, if no obstacle is in the
45  IV,  4 |      upward movement of fire, the downward movement of earth and all
46  IV,  5 |         is heavy and always moves downward. Bodies composed of kinds
47  IV,  5 |           both the upward and the downward motion. Hence air and water
48  IV,  5 |       withdrawn such a body moves downward until it reaches the body
49  IV,  5 |           enough to overpower the downward impulse of the water. Nor
50  IV,  5 |     upward, so fire fails to move downward when air is withdrawn from
51  IV,  5 |     lightness. The other two move downward when the body beneath is
52  IV,  5 |           or all things will move downward, and the second motion will
53  IV,  5 |           has been shown that the downward and upward movements are
54  IV,  5 |         nothing to move uniformly downward. Further, it will follow
55  IV,  5 |          intermediate bodies move downward in some cases quicker than
56  IV,  5 |     portion of air whatever moves downward. And the same reasoning
57  IV,  5 |         be void, earth, as moving downward, plenum; and in air, it
58  IV,  5 |          a certain quantity moves downward more quickly than a little
59  IV,  5 |          not have, and earth goes downward because it has plenum, so
60  IV,  5 |    something else, and water goes downward because of some special
61  IV,  5 |        and air excel water in the downward movement, as we have already
62  IV,  6 |        for their moving upward or downward in general, though it will
63  IV,  6 |         force responsible for the downward motion of the heavy body