Former HP CEO Carly Fiorina was a medieval history and philosophy major at Stanford University.
Fiorina was president and CEO of Hewlett-Packard Company from 1999 to 2005 and served as chairwoman of the board from 2000 to 2005.
In addition to her undergraduate history and philosophy degree, which she earned in 1976, she holds an MBA from the Robert H. Smith School of Business at the University of Maryland, and an M.S. in business from MIT's Sloan School.
Activist investor Carl Icahn was a philosophy major at Princeton University.
Icahn is the chairman of Icahn Enterprises and is one of the most well-known and aggressive activist investors of our time, buying and eventually folding Trans World Airlines, and more recently trying to take over Netflix.
His philosophy thesis for his 1957 degree was titled "The Problem of Formulating an Adequate Explication of the Empiricist Criterion of Meaning." He also went to New York University's Medical School, but dropped out without graduating.
Former FDIC Chair Sheila Bair was a philosophy major at the University of Kansas.
Until last summer, Bair served as the chairwoman of the Federal Deposit Insurance Corporation, having been appointed by George W. Bush in 2005. She helped prevent the financial system from collapsing in 2008. She's since written a book, "Bull by the Horns: Fighting to Save Main Street from Wall Street and Wall Street from Itself."
Bair received her B.A. in philosophy from the University of Kansas and later got a J.D. from the same school.
Hedge fund manager George Soros was a philosophy major at the London School of Economics.
Soros, the chairman of Soros Fund Management, is one of the most successful hedge fund managers of all time. He's particularly well known for a 1992 bet against the pound, which earned him the nickname "the man who broke the Bank Of England."
In college while studying under renowned philosopher Karl Popper, Soros worked as a railway porter and a waiter to pay his tuition.
Former Fannie Mae CEO Herbert Allison Jr. was a philosophy major at Yale University.
Allison Jr. rose through the ranks at Merrill Lynch, eventually becoming its chief operating officer. He left the company in mid-1999 and went on to serve as CEO of Fannie Mae and to oversee the Troubled Asset Relief program.
He earned a B.A. in philosophy from Yale, served four years in the Navy, and then got his MBA from Stanford.
Former Time Warner CEO Gerald Levin was a philosophy major at Haverford College.
Levin joined Time Inc.'s HBO in the 1970s and helped develop the business model that made HBO a huge success. He later engineered the merger with Warner Carner that turned the company into a true media giant. He became CEO in the early '90s. However, his tenure ended less positively with a disastrous merger with AOL.
As a philosophy major at Haverford College, Levin studied the continuity between Jewish and Christian theology.
Overstock.com founder and CEO Patrick Byrne got a Ph.D. in philosophy from Stanford University.
Byrne almost made philosophy his career. After getting an undergraduate degree from Dartmouth in Chinese studies, he went on to get a doctorate in philosophy from Stanford.
Byrne did teach at Standford briefly but ultimately decided to pursue a career in business. He helped found Overstock in 1999, took over as CEO the same year, and took it public in 2002.
Flickr co-founder Stewart Butterfield got both a Bachelor's and Master's degree in philosophy.
Butterfield founded Flickr with his then-wife Caterina Fake in 2004. About a year later, Yahoo snapped the photo-sharing site up for $35 million. He's now working on Slack, a workplace communication tool.
Both his undergraduate degree from the University of Victoria and his Master's from Cambridge were in philosophy, focusing on the philosophy of the mind.
PayPal co-founder Peter Thiel was a 20th century philosophy major at Stanford University.
Thiel is a co-founder and former CEO of PayPal. He currently serves as president of Clarium Capital and as a managing partner at venture capital firm the Founder's Fund. He was also the first outside investor in Facebook.
Despite his well-publicized criticism of higher education, Thiel got his undergraduate degree in 20th century philosophy at Stanford in 1989, and a law degree in 1992. His pronounced libertarian streak came out at the school, and he co-founded the conservative/libertarian Stanford Review newspaper in 1987.