The main themes in Richard Sheridan's School for Scandal are gossip and malice. The play, to a great degree, satirizes the vices of the upper classes of the period.
Another major theme is honour. The major difference between the good and the bad characters in the play is that the good characters are motivated by honour, even when they make honest mistakes or misjudgements and the evil characters have abandoned honour. A related theme is hypocrisy, which Sheridan shows to be morally bad and dishonourable.
One of the moral themes has to do with the aristocracy who engage in slander as fun. Even while malicious gossip is the most entertaining part of this, as many Restoration dramas, Sheridan shows the harm it does. This poses a thematic paradox in that it makes us question our own role as an audience who derive enjoyment from malicious gossip in the play, albeit only as spectators of a fictional text.