it cannot be removed except by force: but it does not set out towards the center except by going down. </s>
<s id="id.5.0.26.00.08">Furthermore: what is moved naturally must be moved towards something determinate: but in what is upward, there is nothing of which we could say, This is the upward limit; on the contrary there can be infinite limits upward, and upward is extended without end: hence nothing can be moved naturally without end, towards the indeterminate -- hence, upward. </s>
<s id="id.5.0.26.00.09">Now concerning downward the same cannot be said: for there is a certain limit of the downward, one, finite, and even indivisible, from which a thing cannot be removed even by the width of a fingernail by seeking the downward; and such is the center. </s>
<s id="id.5.0.26.00.10">And do not tell me that there exists an upward limit, namely the concave sphere of the Moon {1}: for this is false. </s>
<s id="id.5.0.26.00.11">For the limit of a certain motion must be such that what recedes from it is no longer moved by the motion of which it was the limit: but the concave sphere of the Moon is not such; for the limit of upward motion is not such that what recedes from there cannot be moved further upward. </s>
<s id="id.5.0.26.00.12">But the center is so much the limit of downward motion that nothing, receding from there, can be moved downward more. </s>
</p>
<p>
<s id="id.5.0.26.01.00"/>
<s id="id.5.0.26.01.01">Remoteness from the center is infinite; but proximity is finite and determined by the center itself: hence if there is something endowed with the ability of fleeing from the center, surely this thing will be suited to be moved without end. </s>
<s id="id.5.0.26.01.02">What could be more absurd than this? </s>
</p>
<p>
<s id="id.5.0.26.02.00"/>
<s id="id.5.0.26.02.01">A motion to which a limit cannot be assigned cannot be natural: but to upward motion a limit cannot be assigned: hence upward motion is not natural. </s>
<s id="id.5.0.26.02.02">The minor is proved: a motion is delimited at a place from which, by the same motion, it is not possible to recede (for if by the same motion one could progress farther, the limit would not be there): but motion upward is nowhere delimited in such a way that from that place by the same motion, namely upward, it would be impossible to be brought farther: hence upward motion is nowhere delimited; hence it is deprived of a limit; hence it cannot be natural. </s>
<s id="id.5.0.26.02.03">Now it is evident that there is nowhere that a limit of upward motion can be placed, from which by the same motion it is impossible to be brought farther: for if any place is assigned [as a limit], it is possible to recede from it by going up, and another can be assigned which is more distant from the center than it. {1}</s>
</p>
</subchap2>
<subchap2>
<p>
<s id="id.5.0.27.00.00"/>
<s id="id.5.0.27.00.01">The disparity between upward motion and downward motion is as great as can be. </s>
<s id="id.5.0.27.00.02">For, in addition to the things that have just been said, there is also the following difference: the fact is that it never happens that downward motion is helped by the medium, but is always </s>
