and one that seemingly had so sound a philosophical basis,
evidenced the iconoclastic nature of his genius. That he did not
rest content until he had demonstrated the validity of his
revolutionary assumption shows how truly this great theorizer
made his hypotheses subservient to the most rigid inductions.


GALILEO GALILEI

While Kepler was solving these riddles of planetary motion, there
was an even more famous man in Italy whose championship of the
Copernican doctrine was destined to give the greatest possible
publicity to the new ideas. This was Galileo Galilei, one of the
most extraordinary scientific observers of any age. Galileo was
born at Pisa, on the 18th of February (old style), 1564. The day
of his birth is doubly memorable, since on the same day the
greatest Italian of the preceding epoch, Michael Angelo, breathed
his last. Persons fond of symbolism have found in the coincidence
a forecast of the transit from the artistic to the scientific
epoch of the later Renaissance. Galileo came of an impoverished
noble family. He was educated for the profession of medicine, but
did not progress far before his natural proclivities directed him
towards the physical sciences. Meeting with opposition in Pisa,
he early accepted a call to the chair of natural philosophy in
the University of Padua, and later in life he made his home at
Florence. The mechanical and physical discoveries of Galileo will
claim our attention in another chapter. Our present concern is
with his contribution to the Copernican theory.

Galileo himself records in a letter to Kepler that he became a