The aggression was provoked by all those gratuitous insults.

As Paul says, it is really perfectly gratuitous ("es ist im grunde reine willkur") to call the case we have in German (and Old English) a dative, for besides the functions of the dative it fulfils the functions of the old locative, ablative, and instrumental.

People gratuitously making fools out of themselves is a consequence of a pluralistic and permissive society.