What is the theme in The Virtue of Selfishness by Ayn Rand?

Individualism is a theme in this book. The foundation of the ethical theory of Objectivism described and explained by Rand and Branden in this book is the individual. When searching for the "meaning of life" Rand had to look no further than the self. She believes that the survival of the human race demands the survival of individual humans. Therefore, a human must live using her own mind to guide her actions. Such is the principle of individualism. While Rand concedes that humans are social animals and their chances for survival are greater as individuals if they live in a society with other humans, they must still uphold the principle of individualism.