Mr. Hardcastle is a typical upper class gentleman. He is indulgent and has a keen sense of humour. His nature makes it easy for him to tolerate his wife's extravagances and pretentions, as well as bear with his mischievous, wayward stepson. Tony Lumpkin is a pampered young man who unequivocally rejects the authority exerted by his mother and the restrictions she tries to place on him. Mrs. Hardeastle thinks she is doing the best for her son, but Tony thinks otherwise. Such doting on her son, which he resents, is a source of amusement rather than annoyance for Mr. Hardcastle, who obviously does not harbour any ill towards the young man.
Being clear in his mind that any misconduct on the part of the young man stems from his mother's spoiling him, Mr. Hardcastle's feeling towards his stepson is benign enough. Indeed, through the sardonic comments that he passes about Tony, it can be seen that he holds no against Tony. When the play opens, Mr. Hardcastle is seen trying to show his wife how much she is mistaken about her own son and her attitude towards him. His comment that Tony's learning comprises "a mere composition of tricks and mischief' is quite harmless. He is not made angry by his wife's defence of Tony's pranks as "humour". Rather, he, on his part, catalogues Tony's mischiefs: "burning the footmen's shoes, frightening the maid, and worrying the kittens". These he thinks are not funny. "It was but yesterday he fastened my wig to the back of my chair" and when Mr. Hardcastle tries to bow to Mrs. Frizzle, his baldness is uncovered as the wig comes off hanging on the chair. Mr, Hardcastle good-naturedly mocks his wife's assertion that Tony is sickly and explains that the young man simply drinks too much. When Mrs. Hardcastle says that Tony is consumptive Mr. Hardcastle disagrees, saying that Tony is only "growing too fat". Tony enters while this discussion goes on but will not stay to "give Papa and I a little of your company" because he simply must be at "the ate-house, the old place: "I thought so", Mr. Hardcastle humorously remarks, Clearly, Mr. Hardcastle is not opposed to "a pair that only spoil each other".
Throughout the play, Mr. Hardcastle's attitude towards Tony Lumpkin is light-hearted. In the penultimate scene where the prankster takes his mother round and round the house to tease her, Tony notes that his mother has been spoiling him and so she must "take the fruits on't". Mr. Hardcastle's comment is in character: "There's morality, however, in his reply". This is an unusual approval of Tony's weird reaction to his mother's love and doting. Even the question of Tony's real age, as far as Mr. Hardcastle is concerned, has been a settled matter all along.
Points to note:
(1) Mr. Hardcastle's view of Tony as a pampered child and blaming it all on Mrs. Hardcastle, Tony's mother.
(2) Mr. Hardcastle's good humoured tolerance of Tony's pranks, some of which affect him directly.
(3) His disposition that Tony has already come of age and needs to be on his own,
(4) His approval of Tony teasing his own mother.