whys and wherefores

whys and wherefores pl (normally plural, singular why and wherefore)

1. (set phrase) The reasons or motivations for a fact, action, or decision, especially the complete set of such reasons or motivations.
   • 1887, George Bernard Shaw, An Unsocial Socialist, ch. 5:

     I can no more tell you the whys and wherefores of myself than I can lift myself up by the waistband and carry myself into the next county.

   • 1908, Lucy Maud Montgomery, Anne of Green Gables, ch. 1:

     [I]f she noticed anything odd or out of place she would never rest until she had ferreted out the whys and wherefores thereof.

   • 2004 Sept 5, Albert M. Forget, "Question integrity of vets attacking Kerry," Seattle Post-Intelligencer (retrieved 13 May 2011):

     Of the hundreds of thousands who served in Vietnam, most still do not understand the whys and wherefores of our involvement.

• explanation

• whys and wherefores at OneLook Dictionary Search