Who is John Galt ?

“There are four types of people in the world. There are entrepreneurs – who are the guys who get out of bed in the morning and say ‘How can I make money by making things better for people ?’ There are contra-preneurs – who are all the governments and bureaucrats and regulators who try to stop that happening, make it difficult or ban it. There are the con-trepreneurs.. who pretend to be doing the first thing but are just lining their own pockets, usually with government subsidies, with the help of the second group. And there are the non-trepreneurs – which is all the rest of us, who must be pretty bloody thankful every time we jump out of bed that the first lot keep doing it.”

Who is John Galt ?