Calisthenics are a form of exercise that originated in Ancient Greece. They include Jumping Jacks, Crunches, Sit-ups, Pull-ups and Squats.
Locke (1632-1704) was the first of the British Empiricist philosophers. Known as the 'Father of Liberalism', his ideas had great influence in Britain and France amongst thinkers such as Rousseau, Montesquieu and Voltaire, ultimately inspiring the American Declaration of Independence.
Robert Pirsig mentions him here for his belief that we are born tabula rasa, with a 'blank slate', meaning that all knowledge is passed into consciousness through our sensory perception.