Quotation:

 Plato quotes (Ancient Greek Philosopher He was the world's most influential philosopher. 428 BC-348 BC)

 Bertrand Russell quotes (English Logician and Philosopher 1872-1970)

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

 Galileo Galilei quotes (Italian natural Philosopher, Astronomer and Mathematician who made fundamental contributions to the development of the scientific method and to the sciences of motion, astronomy and strength of materials. 1564-1642)

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

 Roger Bacon quotes

 S. Gudder quotes

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

 Charles Caleb Colton quotes (English sportsman and writer, 1780-1832)

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