Book,  Paragraph

 1   I,  2 |           a circular movement. By constraint, of course, it may be brought
 2   I,  7 |       move either naturally or by constraint: and if by constraint, it
 3   I,  7 |          by constraint: and if by constraint, it possesses also a natural
 4   I,  8 |         and move naturally and by constraint. A thing moves naturally
 5   I,  8 |         in which it rests without constraint, and rests naturally in
 6   I,  8 |         to which it moves without constraint. On the other hand, a thing
 7   I,  8 |      other hand, a thing moves by constraint to a place in which it rests
 8   I,  8 |        place in which it rests by constraint, and rests by constraint
 9   I,  8 |          constraint, and rests by constraint in a place to which it moves
10   I,  8 |        place to which it moves by constraint. Further, if a given movement
11   I,  8 |          given movement is due to constraint, its contrary is natural.
12   I,  8 |       natural. If, then, it is by constraint that earth moves from a
13   I,  8 |          there rests here without constraint, its movement hither will
14   I,  8 |     mutually contrary, are due to constraint? No, for a body which has
15   I,  8 |         at all cannot be moved by constraint. If then the bodies have
16   I,  8 |         the other down; nor is it constraint, like the "extrusion" of
17   I,  8 |         the end if it were due to constraint or extrusion; for a constrained
18   I,  8 |         in speed as the source of constraint becomes more distant, and
19   I,  8 |          and a body moves without constraint to the place whence it was
20   I,  8 |      place whence it was moved by constraint.~A consideration of these
21  II,  1 |       since the movement involves constraint, being imposed on the first
22  II,  9 |           of animate nature or of constraint. It is as though nature
23  II,  13|          is any natural movement, constraint will not be the sole principle
24  II,  13|          rest. If, then, it is by constraint that the earth now keeps
25  II,  13|           at the centre is due to constraint; but there must be some
26  II,  14|         from the centre except by constraint. For a single thing has
27  II,  14|          the downward movement to constraint, and it is better to keep
28  II,  14|          than that which it is by constraint and contrary to nature.
29 III,  2 |        movement they must move by constraint: and the constrained is
30 III,  2 |  somewhere, and there rest not by constraint but naturally. But a natural
31 III,  2 |          must cause motion not by constraint but naturally. If there
32 III,  2 |         series is always moved by constraint, we shall have an infinite
33 III,  2 |           have been due either to constraint or to their nature. And
34 III,  2 |      other bodies, moving without constraint, as they came to rest in
35 III,  2 |       lightness, must be moved by constraint, and must continue its constrained
36 III,  2 |        due either to nature or to constraint, movement which is natural,
37 III,  2 |       That is why a body moved by constraint continues to move when that
38 III,  6 |          it might move, either by constraint, i.e. unnaturally, or in
39 III,  6 | unnaturally, or in the absence of constraint, i.e. naturally. If, then,
40  IV,  5 |          place of fire, except by constraint; and in that way water also