Jane Austen, in Pride and Prejudice, uses Mr. Darcy's first marriage proposal to shed a great deal of light on Mr. Darcy's character, and also show society's opinion of the Bennet family.
When Mr. Darcy first walks into the room, Austen makes a point of showing that he asks how Elizabeth is feeling in a "hurried manner" (Ch. XI, pemberley.com). She also portrays him as being "agitated," or unrestful. The fact that he asks about her health so hurriedly demonstrates that he came to call on Elizabeth with a great deal more on his mind than just the headache that prevented Elizabeth from joining the company for tea at Rosings. In addition, the fact that he cannot sit still demonstrates that he is struggling with whatever is on his mind. Finally, he bursts out with "In vain have I struggled...My feelings will not be repressed" (Ch. XI, pemberley.com). His use of the words "vain" and "struggle" prove that he feels it is beneath his dignity to be in love with Elizabeth and has tried to stop himself.
Elizabeth is very correct when she accuses Mr. Darcy of stating that he loves her "against [his] will, [his] reason, and even against [his] character" (Ch. XI, pemberley.com).
However, Mr. Darcy is also correct when later in his letter he explains that he resisted the idea of marrying her, not just because her family is not of noble birth, but because he repeatedly saw her family behave disrespectfully in society. He states that he saw them behave with a "total want of propriety...betrayed by [her mother], by [her] three younger sisters...and even by [her] father" (Ch. XII, pemberley.com).
In sum, even though Mr. Darcy's first proposal seems harsh and rude, it is an extremely honest proposal. Mr. Darcy neither hid the struggle he felt with respect to wanting to marry into a family that is socially, and ethically beneath him, nor did he hide his reasons for thinking her family beneath him--and he was right.