The Collaborative International Dictionary of English v.0.48:

Pro \Pro\, adv.
   For, on, or in behalf of, the affirmative side; -- in
   contrast with con.
   [1913 Webster]

   Pro and con, for and against, on the affirmative and on the
      negative side; as, they debated the question pro and con;
      -- formerly used also as a verb.

   Pros and cons, the arguments or reasons on either side.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "pro and con":
   agitate, argue, argumental, argumentative, canvass, combative,
   contentious, controversial, debate, dialectic, discept,
   disputatious, dispute, eristic, ill-humored, litigious, logomachic,
   pilpulistic, polemic, quarrelsome, thrash out



Bouvier's Law Dictionary, Revised 6th Ed (1856):

PRO AND CON. For and against. For example, affidavits are taken pro and con.