commentary these words, written more than half a century before
Galileo was born, form on the famous expression so often quoted
because supposed to have been drawn from Galileo by the condemnation
of his doctrine at Rome: {21} _E pur se muove_--"and yet it moves!"
Cusanus was a Cardinal, the personal friend of three popes, and he
seems to have had no hesitation in expressing his opinion in the
matter. In the same manuscript the Cardinal adds: "And to my mind the
earth revolves upon its axis once in a day and a night." Cusanus was,
moreover, one of the most independent thinkers that the world has ever
seen, yet he was intrusted by the pope about the middle of the
fifteenth century with the reformation of abuses in the Church in
Germany. The pope seems to have been glad to be able to secure a man
of such straightforward ways for his reformatory designs.

The ideas of Nicholas of Cusa with regard to knowledge and the liberty
of judgment in things not matters of faith can be very well
appreciated from some of his expressions. "To know and to think," he
says in one passage, "to see the truth with the eye of the mind is
always a joy. The older a man grows, the greater is the pleasure it
affords him; and the more he devotes himself to the search after
truth, the stronger grows his desire of possessing it. As love is the
life of the heart, so is the endeavor after knowledge and truth the
life of the mind. In the midst of the movements of time, of the daily
work of life, of its perplexities and contradictions, we should lift
our gaze fearlessly to the clear vault of heaven and seek ever to
obtain a firmer grasp of, and keener insight into, the origin of all
goodness and duty, the capacities of our own hearts and minds, {22}
the intellectual fruits of mankind throughout the centuries, and the
wondrous works of nature around us; but ever remembering that in
humility alone lies true greatness, and that knowledge and wisdom are
alone profitable in so far as our lives are governed by them."
[Footnote 1] It is no wonder, then, that the time was ripe for
Copernicus and his great work in astronomy, nor that that work should
be accomplished while he was a canon of a cathedral and for a time the
vicar-general of a diocese.

It is now nearly five years since Father Adolph Muller, S.J.,
professor of Astronomy in the Pontifical Gregorian University of Rome,
and director of a private observatory on the Janiculum in that city,
wrote his his