The Collaborative International Dictionary of English v.0.48:

Dialectician \Di`a*lec*ti"cian\, n. [Cf. F. dialecticien.]
   One versed in dialectics; a logician; a reasoner.
   [1913 Webster]

WordNet (r) 3.0 (2006):

dialectician
    n 1: a logician skilled in dialectic