One of the last jobs in FF III (DS) is Sage, a better version of Redmage (thaty´s what my brother told me).
But Sage can cast both White magic and Black magic (all levels) so the question is: Why even have Devout and Magus???
Sage can cast both White and Black magic (all 8 levels) BUT you get the Sage the same time as Devout and Magus.