Quotation:

 Aristotle quotes (Ancient Greek Philosopher, Scientist and Physician, 384 BC-322 BC)

 Albert Einstein quotes (German born American Physicist who developed the special and general theories of relativity. Nobel Prize for Physics in 1921. 1879-1955)

 wolfdyke

 Robert M. Hutchins quotes (American Educator and Writer, active in forming the Committee to Frame a World Constitution (1945), led the Commission on Freedom of the Press (1946), and vigorously defended academic freedom, opposing faculty loyalty oaths in the 1950s. 1899-1977)

 Ralph Waldo Emerson quotes (American Poet, Lecturer and Essayist, 1803-1882)

 Epictetus quotes (Greek philosopher associated with the Stoics, AD 55-c.135)

 John Dewey quotes (American Philosopher, Psychologist and Educator, 1859-1952)

 Bel Kaufman quotes

 Socrates quotes (Ancient Greek Philosopher, 470 BC-399 BC)

 Herbert Spencer quotes (British social Philosopher, 1820-1903)