s; and high and noble, because of its
certainty, which is without any defect, even as that which springs
from the most perfect and most regular principle. And if any one
believe that there is defect in it, it is not on the part of the
Science, but, as Ptolemy says, it is through our negligence, and to
that it must be imputed.

CHAPTER XV.

After the comparisons which I have made of the seven first Heavens, we
must now proceed to the others, which are three, as has been often
stated.

I say that the Starry Heaven may be compared to Physics because of
three properties, and to Metaphysics because of three others. For it
shows us of itself two visible things, such as the multitude of stars
and such as the Galaxy, that white circle which the common people call
the Path of St. James. It shows to us also one of the poles, and keeps
the other hidden from us. And it shows to us one movement alone from
East to West; and another, which it makes from West to East, it keeps
almost, as it were, hidden from us. Therefore, in due order are to be
seen, first the comparison with the Physical and then that with the
Metaphysical.

I say that the Starry Heaven shows us many stars; for, according to
what the wise men of Egypt have seen, even to the last star which
appeared to them in the Meridian, they place there twenty-two thousand
bodies of stars, of which I speak. And in this it has the greatest
similitude with Physics, if these three numbers, namely, Two, and
Twenty, and Thousand, are regarded well and subtly. For by the two is
meant the local movement, which is of necessity from one point to
another; and by the twenty is signified the movement of the
alteration, for, since from the ten upwards one advances not except by
altering this ten with the other nine and with itself; and the most
beautiful alteration which it receives is its own with itself, and the
first which it receives is the twenty; reasonably by this number the
said movement is signified. And by the thousand is signified the
movement of increase, which in name, that is, this thousand, is the
greater number, and to increase still more is not possible except by
multiplying this. And these three movements alone are observed in
Physics, as it is demonstrated in the fifth chapter of his first book.

And because of the Milky Way, this Heaven has a great similitude with
Metaphysics. Wherefore, it is to be known that concerning this Galaxy
the Philosophers have had