Mansfield Park is the most controversial of Austen's major novels. Regency critics praised the novel's wholesome morality, but many modern readers find Fanny's timidity and disapproval of the theatricals difficult to sympathise with and reject the idea (made explicit in the final chapter) that she is a better person for the relative privations of her childhood. Jane Austen's own mother thought Fanny "insipid", and many other readers have found her priggish and unlikeable. Other critics point out that she is a complex personality, perceptive yet given to wishful thinking, and that she shows courage and grows in self-esteem during the latter part of the story. Austen biographer Claire Tomalin, who is generally rather critical of Fanny, argues that "it is in rejecting obedience in favour of the higher dictate of remaining true to her own conscience that Fanny rises to her moment of heroism." But Tomalin reflects the ambivalence that many readers feel towards Fanny when she also writes: "More is made of Fanny Price's faith, which gives her the courage to resist what she thinks is wrong; it also makes her intolerant of sinners, whom she is ready to cast aside."
The story contains much social satire, targeted particularly at the two aunts.
At one point, Edward Said implicated the novel in western culture's casual acceptance of the material benefits of slavery and imperialism (a connection already made by Vladimir Nabokov in his Lectures on Literature, delivered in the 1940s although not published until 1980), citing Austen's failure to mention that the estate of Mansfield Park was made possible only through slave labour. At another point, however, he seems to have acknowledged that Jane Austen disapproved of slavery:
"All the evidence says that even the most routine aspects of holding slaves on a West Indian sugar plantation were cruel stuff. And everything we know about Jane Austen and her values is at odds with the cruelty of slavery. Fanny Price reminds her cousin that after asking Sir Thomas about the slave trade, "there was such a dead silence" as to suggest that one world could not be connected with the other since there simply is no common language for both. That is true."
Critics such as Gabrielle White, have criticised Said's condemnation of Jane Austen and western culture, maintaining that Austen and other writers, including Samuel Johnson and Edmund Burke, opposed slavery and helped make its eventual abolition possible. Claire Tomalin, following literary critic Brian Southam, claims that Fanny, usually so timid, questions her uncle about the slave trade and receives no answer, suggesting that her vision of the trade's immorality is clearer than his. However, Ellen Moody has challenged Southam's interpretation, arguing that Fanny's uncle would not have been "pleased" (as the text suggests) to be questioned on the subject if Southam's reading of the scene were correct.
It could also be argued that Jane Austen was sublimely indifferent (at least in her novels) to the outside world. Mansfield Park was written at the height of the Napoleonic War, yet the war is barely even mentioned in this or any other of her novels. The Industrial Revolution was in full swing and the country was in turmoil as a result, again barely a mention—her novels contain not a single mention of the steam engine, the growth of the manufacturing cities or even the turnip (which had a much more profound effect on the British economy than any plant with the exception of cotton—also not mentioned). She even manages to omit any mention of the abolition of the slave trade of 1808, four years before she started the novel and the culmination of a huge, controversial public campaign - although slavery itself had not been abolished in the British Empire.