Julius Scaliger, in his work against Cardano, in exercice #28 {1}, brings forth certain arguments against those who say that projectiles are moved by the air. </s>
</p>
</subchap2>
<subchap2>
<p>
<s id="id.5.0.14.00.00"/>
<s id="id.5.0.14.00.01">Themistius, on the subject of text #74 of Physics Book IV [216a9-21] says {1}: It is thus that since the void yields uniformly, but in fact it does not yield in any way (as indeed it is nothing, very clever the man who can fancy the void yielding), thus the result is that the differences of heavy things and things light, that is the variations of things, are suppressed, and what follows is that the speed of all things that are moved comes to be equal and indiscriminate. </s>
<s id="id.5.0.14.00.02">So much for the words of Themistius: which in fact are not only false, but in fact it is their contrary that is true; for it is only in the void that the heavinesses show their difference precisely and naturally, and it is only there that the swiftnesses of their motions show their difference to the greatest extent. </s>
<s id="id.5.0.14.00.03">Thus let a chapter be written {1}, in which these things are demonstrated. </s>
</p>
</subchap2>
<subchap2>
<p>
<s id="id.5.0.15.00.00"/>
<s id="id.5.0.15.00.01">A motor impresses contrary qualities in a projectile, namely upward and downward: because the beginning of the motion depends on the will, which has the power to move the arm upward or downward; {1} and the impelling force upward is not different from the one impelling downward. </s>
<s id="id.5.0.15.00.02">There is the example of the steel spring in clocks, which moves [the arms of] the clock either upward or downward, either forward or backward, depending on [the direction] it is turned: its intention is to unwind and straighten itself, just as the intention of the arm is to remove the stone from itself.</s>
</p>
</subchap2>
<subchap2>
<p>
<s id="id.5.0.16.00.00"/>
<s id="id.5.0.16.00.01">There will be many who, after they have read my writings, will turn their mind, not to consider whether the things I have said are true, but only to seek in what way, whether rightly or wrongly, they could undermine my opinions. </s>
</p>
</subchap2>
<subchap2>
<p>
<s id="id.5.0.17.00.00"/>
<s id="id.5.0.17.00.01">It is better to say that things that are moved naturally are moved by the medium than [to say that] things [that are moved] by violence [are moved by the medium].</s>
</p>
</subchap2>
<subchap2>
<p>
<s id="id.5.0.18.00.00"/>
<s id="id.5.0.18.00.01">Aristotle, in <i>De Caelo</i> Book I, text #89 [277b1-2], says: Things that are moved are not moved by another thing, as through extrusion. </s>
<s id="id.5.0.18.00.02">The contrary of which, however, could be defended. </s>
