inferior
sciences she ought not to arrogate to herself the right to judge them;
for this would be as if an autocratic prince, being neither physician
nor architect, should undertake to administer medicines and erect
buildings to the danger of the lives of his subjects.

Again, to command the professors of astronomy to confute their own
observations is to enjoin an impossibility, for it is to command them
not to see what they do see, and not to understand what they do
understand, and to find what they do not discover. I would entreat the
wise and prudent fathers to consider the difference between matters of
opinion and matters of demonstration, for demonstrated conclusions
touching the things of nature and of the heavens cannot be changed with
the same facility as opinions touching what is lawful in a contract,
bargain, or bill of exchange. Your highness knows what happened to the
late professor of mathematics in the University of Pisa--how, believing
that the Copernican doctrine was false, he started to confute it, but in
his study became convinced of its truth.

In order to suppress the Copernican doctrine, it would be necessary not
only to prohibit the book of Copernicus and the writings of authors who
agree with him, but to interdict the whole science of astronomy, and
even to forbid men to look at the sky lest they might see Mars and Venus
at very varying distances from the earth, and discover Venus at one time
crescent, at another time round, or make other observations
irreconcilable with the Ptolemaic system.

It is surely harmful to souls to make it a heresy to believe what is
proved. The prohibition of astronomy would be an open contempt of a
hundred texts of the Holy Scriptures, which teach us that the glory and
the greatness of Almighty God are admirably discerned in all His works,
and divinely read in the open book of the heavens.

_III.--FACT AND FAITH_

It may be said that the doctrine of the movement of the sun and the
fixity of the earth must _de Fide_ be held for true since the Scriptures
affirm it, and all the fathers unanimously accept the scriptural words
in their naked and literal sense. But it was necessary to assign motion
to the sun and rest to the earth lest the shallow minds of the vulgar
should be confounded, amused, and rendered obstinate and contumacious
with regard to doctrines of faith. St. Jerome writes: "It is the custom
for the pen-men of Scripture to deliver their judgments in