I begin with a situation described by Smith in “The Theory of Moral Sentiments” and follow up with a parallel situation experienced by Austen’s characters from “Pride and Prejudice.” Smith writes
We sometimes feel for another, a passion of which he himself seems to be altogether incapable; because, when we put ourselves in his case, that passion arises in our breast from the imagination, though it does not in his from the reality. We blush for the impudence and rudeness of another, though he himself appears to have no sense of the impropriety of his own behaviour; because we cannot help felling with what confusion we ourselves should be covered, had we behaved in so absurd a manner.In the scene from “Pride and Prejudice” I quote, Lydia Bennet and her new husband, Wickham, return home after a scandalous affair and mercenary marriage in which Wickham is paid to marry Lydia. The newlyweds show no sign of embarrassment.
Their sister’s wedding day arrived; and Jane and Elizabeth felt for her probably more than she felt for herself. The carriage was sent to meet them at___, and they were to return in it, by dinner time. Their arrival was dreaded by the elder Miss Bennets; and Jane more especially, who gave Lydia the feeling which would have attended herself, had she been the culprit, was wretched in the thought of what her sister much endure….Adam Smith demonstrated conditions under which self-interest causes social good in “The Wealth of Nations.” A quote illustrates this marvelous insight.
Wickham was not at all more distressed than herself, but his manners were always so pleasing, that had his character and his marriage been exactly what they ought, his smiles and his easy address, while he claimed their relationship, would have delighted them all. Elizabeth had not before believed him quite equal to such assurance; but she sat down, resolving within herself, to draw no limits in the future to the impudence of an impudent man. She blushed, and Jane blushed; but the checks of the two who caused their confusion, suffered no variation of colour.
It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest.Jane Austen seems to struggle more with the idea that individual vice (self-interest) can lead to good outcomes but note that it is only an individual’s vice leading to a good outcome for that individual that concerns her. In the book, Elizabeth Bennet and Mr. Darcy discuss the events that lead to their engagement. Two were particularly important. Lydia revealed to Elizabeth that Mr. Darcy had attended her wedding. Anxious for details, she improperly solicited information from her aunt who also attended the wedding and would have known of the arrangements made to induce Wickham to marry. In another scene, Mr. Darcy’s officious aunt attempts to convince Elizabeth not to marry Mr. Darcy. Even though Elizabeth had no understanding with Dr. Darcy, she refused to promise that she would spurn a proposal.
I wonder when you would have spoken [proposed], if I had not asked you [about Lydia]! My resolution of thanking you for your kindness to Lydia had certainly great effect. Too much, I am afraid; for what becomes of the moral, if our comfort springs from a breach of promise, for I ought not to have mentioned the subject? This will never do.A reader might conclude that Austen was a student of Smith, but a more probable explanation is that both were products of the same culture, and with keen powers of observation, interpreted the outcomes caused by the interactions of people in much the same way.
You need not distress yourself. The moral will be perfectly fair. Lady Catherine’s unjustifiable endeavors to separate us, were the means of removing all my doubts. I am not indebted for my present happiness to your eager desire of expressing your gratitude. I was not in a humour to wait for any opening of your’s. My aunt’s intelligence had given me hope, and I was determined at once to know every thing.
Lady Catherine has been of infinite use, which ought to make her happy, for she loves to be of use.
 Biographical information on Jane Austen was found at Jane Austen.org.