Jane Austen's "Pride and Prejudice" raises important moral issues concerned with the institution of marriage.
The most important one being how much money is necessary for a happy and successful marriage:"Pray, my dear aunt, what is the difference in matrimonial affairs, between the mercenary and the prudent motive? Where does discretion end and avarice begin?" (Ch.27)
Jane Austen does not explicitly answer this question by preaching a moral to her readers;but she puts things in perspective by revealing to us the importance of money in marriage and then leaving it to the readers to decide for themselves what is 'moral' or 'immoral'.
In Ch.33 Col Fitzwilliam Darcy the younger son of an earl and obviously a very rich man hints to Elizabeth that he can't marry her: "Our habits of expense make us too dependent, and there are not many in my rank of life who can afford to marrywithout some attention to money." Was he being prudent or avaricious in not marrying Elizabeth? Jane Austen leaves it to the readers to decide.
On the contrary, Darcy also a very rich man overlooks Elizabeth's impoverished financial status and goes out of the way to ensure that Wickham marries Lydia so that the Bennet's family honour is intact. His love for her compels him to virtually bribe Wickham his worst enemy into doing so. This clearly establishes that he is a noble and generous person and Elizabeth readily accepts his second marriage proposal in Ch.58.
Another important theme is the contrasting lifestyle of different social groups which is structurally central to a Jane Austen novel. In "Pride and Prejudice" the landed gentry represented by Darcy is contrasted with the newly rich trading class represented by Bingley.
The novel was written against the background of the threat of an invasion by Napoleon. The militia was a temporary voluntary force raised especially during times of a national emergency. Wickham was a member of this militia. Col.Fitzwilliam Darcy the younger son of an earl, on the contrary, is a fully commissioned officer of the regular army. In those days only an aristocrat or a member of the gentry could afford to purchase a commission in the army. In "Pride and Prejudice" Darcy purchases a commission for Wickham so that Wickham agrees to marry Lydia.
Jane Austen portrays only the elegant aspects of Regency England. The seamy side,however, is sometimes hinted at. Discipline in the army was very harsh and there is a report of a private being whipped. Similarly the prevailing poverty of the lower classes is revealed by the reference to poor feeding.
But most importantly the harsh reality of a bleak future for a dependent unwed old woman is hinted at when Charlotte Lucas' brothers are relieved that Collins is going to marry their sister, for otherwise they would have to look after her in her old age.
'Romantic love' is the central theme which unites all the incidents and the characters in "Pride and Prejudice." But there is nothing 'romantic' about Jane Austen's treatment of 'romantic love' in the novel. 'Romantic love' is checked and controlled by the incomes and financial freedom of the partners involved. In this manner Jane Austen is able to blend 'romance' and 'realism.' For example, Lydia and Wickham who elope 'romantically' have to be rescued by the generosity of Darcy before they are married.
The restraining power of money on 'romantic love' is spelt out in the thematic statement found in Ch.27, "Where does discretion end, and avarice begin?", when Elizabeth replies to her anunt's query concerning Miss King the latest lover of Wickham. Her aunt is relieved to know that Elizabeth is not in love with Wickham who has virtually no income at all and is only employed temporarily in the Militia.
Another important consideration in love and marriage was the social class to which the characters belonged:
At that time, ownership of land and not money was the single most important criterion which determined the social status of an individual. Lady Catherine tries unsuccessfully to dissuade Elizabeth from marrying Darcy,because she is poorer than him but Elizabeth angrily retorts: "In marrying your nephew, I should not consider myself as quitting that sphere. He is a gentleman; I am a gentleman's daughter: so far we are equal."(Ch.56).