Jane Austen’s main subject is courtship and marriage. In "Pride and Prejudice" she describes three different kinds of marriage: (a) marriage based on economics, (b) marriage on passion and physical attraction and (c) ideal kind of marriage based on mutual understanding.
Charlotte’s marriage to Mr. Collins is an example of mercenary marriage. Mr. Collins a clergyman, wants to marry Jane. But when he learns that Jane is going to marry Bingley he shifts his attention to Elizabeth. He offers Elizabeth twice and Elizabeth refuses his proposal. Having rejected by Elizabeth he proposes to Charlotte Lucas and she readily accepts his proposal. Charlotte is very happy at the proposal because at the age of twenty seven she has not much beauty to boast of and she fears being spinster. She has no romantic ideas that marriage must be based on love. Through marriage, she only seeks a comfortable home and settled life, free from financial crisis. Thus Charlotte’s marriage to Mr. Collins is not based on love. It is purely a marriage of convenience based on worldly advantages and practical considerations.
The runaway marriage of Lydia and Wickham is based on passion and physical attraction. Lydia is attracted towards Wickham on account of his external charm. She falls for infatuation not for love. She is so infatuated with him that she does not hesitate to lose her virginity to him before her marriage to him. As for Wickham he had no intention of marrying Lydia. But he eloped with her only to get money from her parents. He married her when Darcy paid all of Wickham’s debts and bought him a commission in the army. Thus Lydia-Wickham marriage takes place for infatuation on the side of Lydia and for economic pressure on the side of Wickham. Soon after their marriage they sink into indifference towards each other.
The marriage of Mr. and Mrs. Bennet is also based on physical attraction and ends in mutual forbearance. Mr. Bennet married this woman being captivated by her youth and beauty but he had subsequently discovered that she was a woman with a weak intelligence and narrow mind which put an end to his affection for her. Thus Mr. Bennet’s hope of a happy married life had totally separate lives without any affection or communication between them.
We find the ideal kinds of marriage characterized by the relationships between Darcy and Elizabeth and between Jane and Bingley. The marriage of Jane and Bingley is not simply based on physical attraction but is rationally founded and they possess similarity of feelings and taste. The marriage of Elizabeth and Darcy represents a much more complex state of affairs. They achieve admiration and respect only through the painful process of melting away misunderstanding and self deception. At first they were experienced helped them understand each other and their marriage will be stable because of this mutual experience and understanding.
Thus Jane Austen shows in "Pride and Prejudice" that marriage based on sex and physical attraction leads to unhappiness and marriage based on calm judgment and mutual understanding leads to happiness.