erical geometry on the lines which best suit our
practical intelligence. They gave mankind the framework of astronomy by
determining the relative positions of the heavenly bodies, and they
perceived and correctly stated the elementary principles of equilibrium.
At all these points the immortal group of men who adopted the Copernican
theory at the Renascence, began again where the Greeks had left off. But
modern science starts with two capital improvements on the work of the
Greeks. Measurement there had been from the first, and the effort to
find the constant thing in the variable flux; and from the earliest days
of the Ionian sages the scientific mind had been endeavouring to frame
the simplest general hypothesis or form which would contain all the
facts. But the moderns advanced decisively, in method, by experimenting
and verifying their hypotheses, and in subject-matter, by applying their
method to phenomena of movement, which may theoretically include all
facts biological as well as physical. Galileo, the greatest founder of
modern science, perfectly exemplifies both these new departures.

It is, perhaps, the most instructive and encouraging thing in the whole
annals of progress to note how the men of the Renascence were able to
pick up the threads of the Greeks and continue their work. The texture
held good. Leonardo da Vinci, whose birth coincides with the invention
of the printing-press, is the most perfect reproduction in modern times
of the early Greek sophos, the man of universal interests and capacity.
He gave careful and admiring study to Archimedes, the greatest pure man
of science among the Greeks, the one man among them whose works,
including even his letters, have come down to us practically complete. A
little later, at the beginning of the sixteenth century, Copernicus
gained from the Pythagoreans the crude notion of the earth's movement
round a great central fire, and from it he elaborated the theory which
was to revolutionize thought. Another half-century later the works of
Archimedes were translated into Latin and for the first time printed.
They thus became well known before the time of Galileo, who also
carefully studied them. At the beginning of the seventeenth century
Galileo made the capital discoveries which established both the
Copernican theory and the science of dynamics. Galileo's death in 1642
coincides with the birth of Sir Isaac Newton.

Such is the sequence of the most influential names