But Organ is too stubborn to believe his own son. Not only that, but Tartuffe wants to marry Organ's daughter Mariane. Now if Tartuffe was to marry Mariane, their whole marriage would be fake. The only way to prevent Tartuffe from marrying Mariane is to make Organ somehow find out that Tartuffe is a phony. Organ's role as an authority figure clearly represents nothing but foolishness. Organ's bad role as an authority figure is going to cause Tartuffe to be in charge of the household, and to marry Mariane. Both are bad and will cause nothing but trouble in future since Organ's other family members already know that Tartuffe is just a hypocrite.
In order to make Organ finally get to believe that Tartuffe is a fake, Organ's wife, Elmire makes him hide under a table. The purpose of this is so Organ can hear Tartuffe talk to Elmire. Tartuffe has been seducing Elmire and Elmire wants Organ to hear Tartuffe do that in order to make him finally believe that Tartuffe is only acting as a "good guy." So as organ is hiding under the table, Elmire and Tartuffe begin to start talking. The plan is working and Tartuffe begins seducing Elmire while Organ can hear everything under the table. Now, Organ finally believes that Tartuffe is a hypocrite. Actually, while Organ was hiding under the table, Tartuffe said some derogatory about Organ. Organ is outraged that he was led to believe that Tartuffe was a good guy when in fact he was not. .
At the end of the play, Moliere shows an example of good authority. Tartuffe gets arrested at the end of the play via the King. The King is the one who represents good authority in the play. The King is the one who now brought back order in the household. Now, Tartuffe cannot be in charge of the household, and now Tartuffe is not going to marry Mariane. Mariane was not even in love with Tartuffe; Mariane is in love with another man, Valere. So now everything is going to work out for Mariane thanks to the power of good authority represented by the King.