Human beings, each considered as a single actor within society
- Paine, Thomas - American Revolutionary leader, author of the Common Sense pamphlet
- Paterson, Isabel - Canadian-born, American literary critic, author of The God of the Machine
- Paul, Ron - Texas Republican Congressman, 1988 Libertarian Presidential candidate, 2008 Republican Presidential prospective candidate
- Peart, Neil - Drummer and lyricist for the Rush rock band
- Philosophers - Students and teachers of fundamental principles
- Poirot, Paul L. - Editor of The Freeman (1956-1987)
- Politicians - People who hold or are running for a political office
- Poole, Jr., Robert W. - Founder of Reason Magazine and the Reason Foundation
- Popper, Karl - 20th century Austrian-born British philosopher
- Postrel, Virginia - Author, columnist, former editor of Reason magazine
- Powell, Jim - Historian, author of The Triumph of Liberty
- Presidents, United States - Heads of the Executive branch of the United States government
- Presley, Sharon - Psychologist, executive director of Resources for Independent Thinking
- Professors and teachers - Faculty members at schools, colleges and universities
- Psychologists and Psychiatrists - Non-medical and medical practitioners in the study of the mind and human behavior