"How can anything be foreseen that has no
cause and no distinguishing mark of its coming?
Eclipses of the sun and also of the moon are predicted for many years in advance by men who
employ mathematics in studying the courses and
movements of the heavenly bodies; and the unvarying laws of nature will bring their predictions
to pass. Because of the perfectly regular movements of the moon the astronomers calculate when
it will be opposite the sun and in the earth's shadow
—which is 'the cone of night '1
necessarily, it will become invisible. For the same
reason they know when the moon will be directly
between the earth and the sun and thus will hide
the light of the sun from our eyes. They know in
what sign each planet will be at any given time
and at what time each day any constellation will
rise and set. You see the course of reasoning
followed in arriving at these predictions.