Among the Ibo the art of conversation is regarded very highly, and proverbs are the palm-oil with which words are eaten.

-Achebe, Chinua originally Albert Chinualumogo
  Things Fall  Apart, ch.1. The title is taken fromYeats's poem 'The Second Coming'.

It is a fatal defect of current principles of administration that, like proverbs, they occur in pairs. For almost every principle one can find an equally plausible and acceptable contradictory principle. Although the two principles of the pair will lead to exactly opposite recommendations, there is nothing in the theory to indicate which is the appropriate one to apply.

-Simon, Herbert A
  Administrative Behavior.