may
be presumed that the trial begun at Naples and removed to Rome, combined
with the circumstances of his flight and recusant behavior, rendered the
case too grave for compromise. No one but the Pope in Rome could decide
it.

There is no apparent reason why Bruno left Toulouse, except the
restlessness which had become a marked feature in his character. We find
him at Paris in 1579, where he at once began to lecture at the Sorbonne.
It seems to have been his practice now in every town he visited, to
combine private instruction with public disputation. His manners were
agreeable; his conversation was eloquent and witty. He found no
difficulty in gaining access to good society, especially in a city like
Paris, which was then thronged with Italian exiles and courtiers.
Meanwhile his public lectures met with less success than his private
teaching. In conversation with men of birth and liberal culture he was
able to expound views fascinating by their novelty and boldness. Before
an academical audience it behoved him to be circumspect; nor could he
transgress the formal methods of scholastic argumentation.

Two principal subjects seem to have formed the groundwork of his
teaching at this period. The first was the doctrine of the Thirty Divine
Attributes, based on S. Thomas of Aquino. The second was Lully's Art of
Memory and Classification of the Sciences. This twofold material he
worked up into a single treatise, called _De Umbris Idearum_, which he
published in 1582 at Paris, and which contains the germ of all his
leading speculations. Bruno's metaphysics attracted less attention than
his professed Art of Memory. In an age credulous of occult science, when
men believed that power over nature was being won by alchemy and magic,
there was no difficulty in persuading people that knowledge might be
communicated in its essence, and that the faculties of the mind could be
indefinitely extended, without a toilsome course of study. Whether Bruno
lent himself wittingly to any imposture in his exposition of mnemonics,
cannot be asserted. But it is certain that the public were led to expect
from his method more than it could give.

The fame of his Art of Memory reached the king's ears; and Henri III.
sent for him. 'The king, says Bruno, 'had me called one day, being
desirous to know whether the memory I possessed and professed, was
natural or the result of magic art. I gave him satisfaction; by my
explanations and by demonstrations