Littleman, littleman! The word 'must' isnotto be usedto princes!

-Elizabeth I
   To Robert Cecil when, during her last illness, he told her that she must go to bed. Quoted in Christopher Haigh Elizabeth I (1988), p.24.

   Alle anderen Dinge mu«  ssen; der Mensch ist das Wesen, welches will. All other things must; man is the being who wills.

-Schiller, Friedrich
« 1794  Uber das Erhabene.

Better to use force when you should rather than when you must.

-Shultz, George P(ratt)
  On Soviet alarm at the prospect of US science'turned on' and venturing into the realm of space defence. Turmoil and Triumph.