Billionaire Ray Dalio thinks people should brush up on their Ayn Rand if they want to understand Donald Trump's economic philosophy, which raises a question for a lot of people: Who is Ayn Rand?

Rand has been dead for almost 35 years, but her novels and philosophical tracts are still top sellers, especially in the United States. She retains a large following less for the quality of her fiction than for her message of what could be called a fundamentalist version of individualism. She rejected the idea that free markets create undesirable results such as monopolies.

Rand's philosophy insists on the primacy of the individual's desires above essentially all other considerations, including God. Rand could be described as a devout atheist, and she explicitly said that self-sacrifice was immoral.

Born in 1905, Rand was traumatized as a child when her family's pharmacy business and property were seized by marauding Bolsheviks during the Russian Revolution. Rand emigrated, eventually settling in New York (a city which moved her to tears of joy when she saw it for the first time). By the 1950s, she had gathered a circle of idealistic, fiercely dedicated followers, including a young Alan Greenspan.