What is the theme in Capitalism and Freedom by Milton Friedman?

Liberalism is the main theme of the book. For Friedman, liberalism is not the philosophy of social freedom, the mixed economy (the combination of capitalism and socialism) and expansive social welfare programs. Instead, it is an older creed of those who first called themselves liberals in the 19th century, of what is today called "classical liberalism." Classical liberalism is akin to modern day libertarianism, though it is not as centrally focused on equating justice with respect for private property rights.