Casuist

6 clues
Sophist's cousin
Specious debater
Quibbler of a sort
Student of morality
Disingenuous reasoner
His reasons are false and misleading
Similar answers:
Abacas
Abcas
Acas
Acase
Acaseforholding
Acaseofhives
Acaseofidentity
Acast
Acastle
Acastofthousands
Accas
Accusativecase
Actcasual
Activecase
Adjustincase
Africas
Africasiargentinaruba
Aircastle
Aladdincasino
Alcash