and
saturated with the ecclesiastical divinity of the schoolmen.

[Footnote 124: This theological conception of history inspired the
sacred drama of the Middle Ages, known to us as Cyclical Miracle Plays.]

These forces of the philosophy he sought to supersede, had to be
attacked with their own weapons and by methods adapted to the spirit of
his age. Similar judgment may be passed upon his championship of the
Copernican system. That system was the pivot of his metaphysic, the
revelation to which he owed his own conception of the universe. His
strenuous and ingenious endeavors to prove its veracity, his elaborate
and often-repeated refutations of the Ptolemaic theory, appear to modern
minds superfluous. But we must remember what a deeply-penetrating,
widely-working revolution Copernicus effected in cosmology, how he
dislocated the whole fabric upon which Catholic theology rested, how new
and unintelligible his doctrine then seemed, and what vast horizons he
opened for speculation on the destinies of man. Bruno was the first
fully to grasp the importance of the Copernican hypothesis, to perceive
its issues and to adapt it to the formation of a new ontology.
Copernicus, though he proclaimed the central position of the sun in our
system, had not ventured to maintain the infinity of the universe. For
him, as for the elder physicists, there remained a sphere of fixed stars
inclosing the world perceived by our senses within walls of crystal.
Bruno broke those walls, and boldly asserted the now recognized
existence of numberless worlds in space illimitable. His originality
lies in the clear and comprehensive notion he formed of the Copernican
discovery, and in his application of its corollaries to the Renaissance
apocalypse of deified nature and emancipated man. The deductions he drew
were so manifold and so acute that they enabled him to forecast the
course which human thought has followed in all provinces of speculation.

This leads us to consider how Bruno is related to modern science and
philosophy. The main point seems to be that he obtained a vivid mental
picture (_Vorstellung_) of the physical universe, differing but little
in essentials from that which has now come to be generally accepted. In
reasoning from this concept as a starting-point, he formed opinions upon
problems of theology, ontology, biology and psychology, which placed him
out of harmony with medaeival thought, and in agreement with the thought
of our