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 to his own experience, convincing him that it was not an affair of magic but of science.' Henri, who might have been disappointed by this result, was taken with his teacher, and appointed him Reader Extraordinary--a post that did not oblige Bruno to hear Mass.