Zweig selected these individuals because they represent three distinct yet complementary approaches to mental healing that emerged in different periods, each making lasting contributions to how we understand the relationship between mind and body in healing processes.

The book remains highly relevant as it explores themes that are central to contemporary discussions about alternative medicine, the placebo effect, and the integration of mental and physical health treatment approaches, all of which continue to be debated in modern healthcare.

Zweig takes a balanced, nuanced approach, acknowledging both the revolutionary contributions and the controversies surrounding each healer. He presents their stories with historical context and psychological insight, allowing readers to understand their impact while maintaining critical perspective.