Tony Lumpkin is a character who is important in this play for two reasons. Firstly, he is connected to the important theme of truth and falsehood, which is linked to the theme of appearances and reality. It is he who tells the lie to Marlow and Hastings that makes them believe that the residence of Mr. Hardcastle is actually an inn and that Mr. Hardcastle himself is a member of the working class with pretensions to rise above his station in society. At the same time, he is also introduced in a way that draws a distinction between the way characters are perceived and the actual reality, as the very differing opinions of him that his mother and Mr. Hardcastle have demonstrate. As such, he could be said to be something of a parallel to Marlow, who likewise attracts very different opinions of his character.
However, one of the most important parts of the play places Tony Lumpkin centre stage: it is at the end of the play, when he realises he is actually of age, that he is able to free Constance from their engagement and gain his own freedom from his mother's plans for him:
Witness all men by these presents, that I, Anthony Lumpkin, Esquire of BLANK place, refuse you, Constance Neville, spinster, of no place at all, for my true and lawful wife. So Constance Neville may marry whom she pleases and Tony Lumpkin is his own man again!
Tony Lumpkin is therefore an important character in the way that he is used to introduce important themes, but also in the way that he is the agent that is able to clear the way for one of the couples, Hastings and Constance to marry, simultaneously destroying his mother's plans for him.