1
general::
Phrase(s): on the contrary
Go to to the contrary.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
It's the opposite, as in Is his shoulder hurting?? On the contrary, it's all better, or We thought you didn't like opera.? On the contrary, I love it. This phrase, at first put as by or for or in the contrary, dates from the late 1300s; on has been used since the mid-1800s.
American Heritage Idioms