ns. The burning at the stake of
Giordano Bruno, in the year 1600, was, for example, an object-lesson
well calculated to restrain the enthusiasm of other similarly minded
teachers.

Doubtless it was such considerations that explained the relative silence
of the champions of the Copernican theory, accounting for the otherwise
inexplicable fact that about eighty years elapsed after the death of
Copernicus himself before a single text-book expounded his theory. The
text-book which then appeared, under date of 1622, was written by the
famous Kepler, who perhaps was shielded in a measure from the papal
consequences of such hardihood by the fact of residence in a Protestant
country. Not that the Protestants of the time favored the heliocentric
doctrine--we have already quoted Luther in an adverse sense--but of
course it was characteristic of the Reformation temper to oppose any
papal pronouncement, hence the ultramontane declaration of 1616 may
indirectly have aided the doctrine which it attacked, by making that
doctrine less obnoxious to Lutheran eyes. Be that as it may, the work of
Kepler brought its author into no direct conflict with the authorities.
But the result was quite different when, in 1632, Galileo at last broke
silence and gave the world, under cover of the form of dialogue, an
elaborate exposition of the Copernican theory. Galileo, it must be
explained, had previously been warned to keep silent on the subject,
hence his publication doubly offended the authorities. To be sure, he
could reply that his dialogue introduced a champion of the Ptolemaic
system to dispute with the upholder of the opposite view, and that, both
views being presented with full array of argument, the reader was left
to reach a verdict for himself, the author having nowhere pointedly
expressed an opinion. But such an argument, of course, was specious, for
no one who read the dialogue could be in doubt as to the opinion of the
author. Moreover, it was hinted that Simplicio, the character who upheld
the Ptolemaic doctrine and who was everywhere worsted in the argument,
was intended to represent the pope himself--a suggestion which probably
did no good to Galileo's cause.

The character of Galileo's artistic presentation may best be judged from
an example, illustrating the vigorous assault of Salviati, the
champion of the new theory, and the feeble retorts of his conservative
antagonist:

"Salviati. Let us then begin our discussion with the