This book was revolutionary at the time of its publication because Yates rejected the imposition of 20th century categories on earlier periods. Those who studied Bruno's scientific and mathematical advances ignored his interest in magic and mysticism, and vice versa. Yates surmounted this division and showed how inseparable the two truly were. For instance, Bruno's involvement with Copernicus occurred because he needed more accurate astronomical calculations for his astrological work. This study showed how much overlap there was between the commencement of scientific humanism and the continued belief in magic. Yates' groundbreaking work remains an important call for historians to treat the ideas and thinkers of the past on their own ground rather than imposing modern judgments of their validity.