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This sky is well known to those who are
astronomers. It is it that now gives us the blue
color that extends above into the air, which
we see when the air is pure and clean all around. And
it is so well balanced [=of such great equilibrium] that no violence
may happen there. This is the sky that encloses the
firmament. But I tell you very openly that whatever you may
may understand by hearing of it, no one can take
anything from it nor benefit, nor prove whether it is the truth or not by
any art of demonstration in the way one can see with one's eyes.
For man does not have any sense that is capable of it. But even so I
tell you that we can find the truth through that which is written
in certain places. For some ancient philosophers were
thinking of it, and they found certain arguments [need better word] for it.
[rubric:] This speaks of the crystalline sky and the empyrean sky. [/rubric]
Above the sky that we can see, as some of the ancient philosphers have said,
there is another sky that is all around it, above and
beneath, and that one is like the color of crystal,
white and clear and very pure, and clear and noble,
and it is called the crystalline sky. And above this crystalline sky all