"Antithesis"

       Shakespeare studied rhetoric growing up, and this way of thinking by contrasts and opposites is persistent in his work:  antithesis.

       Many poets and writers use it.   John F. Kennedy's inaugural:  "Ask not what your country can do for you; ask what you can do for your country." 

       I just received Barry Edelstein's book Thinking Shakespeare and found it saying, in part, if you want to get into Shakespeare as a reader or performer, you've got to get with the antithetical mode of thought.  I close with the couplet at the end of  Sonnet #43.    Each day a lover misses seeing his absent love and is only able to see her at nights by imagining her:

               All days are nights to see till I see thee,
               And nights bright days when dreams do show thee me.