Salusbury, Thomas Mathematical collections and translations 1667
author indexprevious page134 / 1206next page
 show/hide xml  show page   search  

116
instead of Aristotle, to prove that they do not.

The answer to
Aristotles first ar­
gument.

SIMPL. This is proved by Aristotle in the same place, when he
saith, that the natural motion of the parts is the right motion
downwards to the centre of the Universe; so that the circular
motion cannot naturally agree therewith.

SALV. But do not you see, that those very words carry in them
a confutation of this solution?

SIMPL. How? and where?

SALV. Doth not he say that the circular motion of the Earth
would be violent? and therefore not eternal? and that this is ab­
surd, for that the order of the World is eternal?

SIMPL. He saith so.

SALV. But if that which is violent cannot be eternal, then by

conversion, that which cannot be eternal, cannot be natural: but
the motion of the Earth downwards cannot be otherwise eternal;
therefore much lesse can it be natural: nor can any other motion
be natural to it, save onely that which is eternal. But if we make
the Earth move with a circular motion, this may be eternal to it,
and to its parts, and therefore natural.

That which is
violent, cannot be
eternal, and that
which cannot be e­
ternal, cannot be
natural.

SIMPL. The right motion is most natural to the parts of the
Earth, and is to them eternal; nor shall it ever happen that they
move not with a right motion; alwayes provided that the impe­
diments be removed.

SALV. You equivocate Simplicius; and I will try to free you
from the equivoke. Tell me, therefore, do you think that a
Ship which should sail from the Strait of Gibralter towards Pale­
stina can eternally move towards that Coast? keeping alwayes an
equal course?

SIMPL. No doubtlesse.

SALV. And why not?

SIMPL. Because that Voyage is bounded and terminated be­
tween the Herculean Pillars, and the shore of the Holy-land; and
the distance being limited, it is past in a finite time, unlesse one by
returning back should with a contrary motion begin the same Voy­
age anew; but this would be an interrupted and no continued
motion.

SALV. Very true. But the Navigation from the Strait of Ma­
galanes by the Pacifick Ocean, the Moluccha's, the Cape di buona
Speranza, and from thence by the same Strait, and then again by
the Pacifick Ocean, &c. do you believe that it may be perpe­
tuated?

SIMPL. It may; for this being a circumgyration, which re­
turneth about its self, with infinite replications, it may be perpetu­
ated without any interruption.

SALV. A Ship then may in this Voyage continue sailing eter­
nally.