epiplexis

from WordNet (r) 3.0 (2006)

epiplexis
    n 1: a rhetorical device in which the speaker reproaches the
         audience in order to incite or convince them

from The Collaborative International Dictionary of English v.0.48

Epiplexis \Ep`i*plex"is\, n. [L., reproof, fr. Gr. ?, fr. ? to
   strike at, reprove; 'epi` + ? to strike.] (Rhet.)
   A figure by which a person seeks to convince and move by an
   elegant kind of upbraiding.
   [1913 Webster]