Sydney J. Harris (1917–1986) American journalist
Reader’s Digest (May 1979)
The Books in My Life (1952) Preface (2nd edition. New York: New Directions Publishing, 1969, p. 12)
Sydney J. Harris (1917–1986) American journalist
Reader’s Digest (May 1979)
John F. Kennedy (1917–1963) 35th president of the United States of America
1962, Address and Question and Answer Period at the Economic Club of New York (549)
Arthur C. Clarke (1917–2008) British science fiction writer, science writer, inventor, undersea explorer, and television series host
The Exploration of Space (1951), p. 111
1950s
“Make it thy business to know thyself, which is the most difficult lesson in the world.”
Miguel de Cervantes (1547–1616) Spanish novelist, poet, and playwright
Source: Don Quixote de la Mancha (1605–1615), Part II (1615), Book III, Ch. 42.
Katharine Graham (1917–2001) American publisher
Quoted by Jane Howard in The Power That Didn't Corrupt http://books.google.com/books?id=MNSxAAAAIAAJ&q=%22Bromidic+though+it+may+sound+some+questions+don-t+have+answers+which+is+a+terribly+difficult+lesson+to+learn%22, Ms. magazine (October 1974)
Muhammad ibn Mūsā al-Khwārizmī
As quoted in: Victor J. Katz (2009) A history of mathematics: an introduction. p. 271
“There is no royal road to learning; no short cut to the acquirement of any art.”
Anthony Trollope book Barchester Towers
Source: Barchester Towers (1857), Ch. 20; this derives from an expression attributed to Euclid.