"Under Saturn's Shadow" primarily focuses on the psychological and spiritual wounds that men carry, rooted in ancient myths and societal expectations. It provides insights into the hidden fears and vulnerabilities that men often conceal and offers a perspective on their struggles and paths to healing.

James Hollis uses the myth of Saturn, the Roman god who devoured his children to prevent them from usurping his power, to illustrate how men have been conditioned to suppress their emotions and vulnerabilities. This myth serves as a metaphor for the destructive patterns imposed by societal expectations on men's mental health.

Some key themes explored in "Under Saturn's Shadow" include the legacy of Saturn, the wounding of men, and the path to healing. These themes delve into how societal expectations impact men's mental health, the various ways men are psychologically and spiritually wounded, and the roadmap for men to heal by embracing their vulnerabilities and seeking support.