The theme of Scandal v/s Morality, in the play School for Scandal

 The School for Scandal, as a comedy of manners, written by Richard Brinsley Sheridan , focuses on the lives and flaws of upper-class people, it is fitting that money or wealth is a strong theme in the play. A major question in the play is whether characters and the audience should believe Charles or Joseph to be the more moral and/or worthy brother.

The critic and essayist William Hazlitt called R B Sheridan’s 1777 play The School for Scandal, ‘if not the most original, perhaps the most finished and faultless comedy which we have.

 The main theme centers around morality.  There are distinct groups of characters - those who are members of the "school for scandal" and those who are not.  In the first group, we see characters who maintain a facade of morality (or "sentiment"), but who spend their days gossiping and manipulating to destroy others.  These are the members of the "school for scandal" - Lady Sneerwell, Joseph Surface, Snake, Sir Benjamin Backbite, and others.  In the moral group, we see Peter Teazle , Sir Oliver, Maria, Moses  his friends, who try to live morally and uprightly.  Then there is a group that doesn't fit either category.  Charles Surface and his friends; this group behaves badly (drinking and womanizing, etc.), but makes no excuses for it.  

Sheridan paints the first group as the most corrupt and the ones who rightly deserve the punishment they receive (banishment from society) when their duplicitous ways are discovered by the end of the play.  Lady Teazle is forgiven for consorting with them, as she is genuinely apologetic and contrite.  Charles, who is nothing but honest, is rewarded for that, in spite of his immoral behavior. 

Morality in The School for Scandal seems to be most judged by the way they treat their  family. This theme is shown through the comparison between Charles and Joseph Surface, brothers who both seek inheritance from their rich uncle Sir Oliver Surface. Sir Oliver goes to each in disguise. He goes to Charles disguised as Mr. Premium, a money lender, and is appalled when Charles agrees to sell the collection of their family's portraits. This act represents him disregarding and disrespecting his family and lineage. However, he refuses to sell the portrait of Sir Oliver, and Sir Oliver completely forgives him. 

Sir Oliver goes to Joseph, who is generally regarded as the more moral and proper brother, dressed as Mr. Stanley, a destitute family member. Joseph is shown to lie and not help Mr. Stanley, even though Sir Oliver knows he has the money to do so. However, Charles, who is deeply in debt and thought to be a selfish young man, does send 100 pounds to Mr. Stanley. Weighing all of this, Sir Oliver decides that Charles will be his heir. This shows that, other moral failings aside, Sir Oliver sees the loyalty and willingness to support one's family as the most worthy trait in a man. It can be surmised that Sheridan wanted to promote this value, especially in cases where it might conflict with perceived social propriety.

Rumour and reputation play a large part in Sheridan’s meticulously crafted play, with gossip being a weapon one can use against someone.

 Sheridan's main message is about being truthful and upfront, not playing games with others' feelings.  The play, which is a Sentimental Comedy, can very much be seen as reaction to the excess of the English Restoration.