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

Another theme to consider is reason vs. whim. Rand and Branden assert the position that to live a virtuous life, individuals must always use reason to make decisions and analyze situations. When adopting values, individuals must ask themselves: Why is this a value? They must be able to answer this question, extracting the answer from their own minds. The employment of reason is imperative to every decision and action. Even in terms of pleasure, people must be able to provide reason for liking an art form or loving another individual. Without reason one has no control over one's reality, and one cannot live successfully without this control.