"To attain knowledge, add things every day.
      To attain wisdom, remove things every day."

                         -- Lao Tzu, Tao Te Ching, ch.48, about 600 B.C..


     "Know the enemy, know yourself; your victory will never be endangered.  
      Know the ground, know the weather; your victory will then be total." 

                         -- Sun Tzu, The Art of War, ch.10, about 500 B.C..


     "Logic is the science of sciences, and the art of arts."

                         -- John Duns Scotus, 13th century.


     "Knowledge is power."

                         -- Francis Bacon, 1598.


     "The art of discovery may advance as discoveries advance." 	

                         -- Francis Bacon, 1620.


     "In mathematics the art of proposing a question 
      must be held of higher value than solving it." 	

                         -- Georg Ferdinand Ludwig Philipp Cantor, 1867.


     "As long as a branch of science offers an abundance of problems, 
      so long is it alive: a lack of problems foreshadows extinction or 
      the cessation of independent development."	

                         -- David Hilbert, 1900.


     "The formulation of a problem is often more essential than its solution,
      which may be merely a matter of mathematical or experimental skill.
      To raise new questions, new possibilities,
      to regard old problems from a new angle,
      requires creative imagination and marks real advance in science."

                         -- Albert Einstein, 1938.


     "The best theory is inspired by practice and 
      the best practice is inspired by theory."

                         -- Donald E. Knuth, 1989.