moralist may be a person who is "unduly concerned with the morals of others" (American Heritage Dictionary). This Austen certainly was not. There is no indication in her novels, early biographies or extant letters that she is "unduly" (i.e., excessively, unreasonably) concerned about morals. A moralist may also be a person who intentionally teaches or studies moral problems, such as a philosopher, like Kant or Descartes. This Austen certainly was not.

Austen lived in the upper class social realm and was a keen observer of human nature and human interactions. She had a particular fondness for love stories, also apparent in her juvenilia, perhaps especially since her own romances (two are hinted at in letters) had unfortunate endings. In this capacity--participant, observer, reporter--Austen's novels touched upon moral issues and exposed moral failings in relation to men's and women's relationship and the relationship of women to 18th and 19th century English society (her first works were written in the 1700s though published in the early 1800s).

The author’s knowledge of the world, and the peculiar tact with which she presents characters ..., reminds us something of the merits of the Flemish school of painting. The subjects are not often elegant, and certainly never grand; but they are finished up to nature, and with a precision which delights ... (Sir Walter Scott, review of Emma, Famous Reviews, R. Brimley Johnson, Editor. 1914.)

Having said this, it is true that a contemporary trend analyzes Austen as moralist even though this is not how she perceived her own work. Austen may be read as a moralist by considering what she observed and exposed about the constraints on young women to marry wealth and prestige, perhaps for the good of the family rather than for their own good. Consider Mrs. Bennet's earnest interest in having Elizabeth accept Collins' proposal so that Elizabeth would be mistress of Longbourn when the entail passed the house and estate into Collins' hands.

Austen may also be read as a moralist by considering what she exposed about a young man's own need to marry wealth, especially a second son or man without private wealth. Consider Colonel Fitzwilliam. He was not the first son so his father's wealth and title would by-pass him altogether. He needed to marry a woman with wealth of her own in order to continue in the upper class.

Also consider Wickham. He was without family wealth and depended upon gifts from friends to live according to the education Darcy Senior gave him. Since Wickham betrayed his friends with surprising regularity, he was forced to marry for greed without scruples about love or esteem.

These are some moral topics that emerge from Austen's work . A targeted reading might yield an identification of Austen as a moralist. In truth, a sincere rendering of genuine observations of society, with no moralistic motive, will reveal moral values, contradictions, issues and problems of that society.     

the little bit, two inches wide, of ivory on which I work with so fine a brush, as produces little effect after much labour ... (Jane Austen letter to nephew James Edward Austen, Monday 16 December 1816)

The original source for the idea of Jane Austen as a moralist came from a 1966 work by philosopher Peter Smith of Oxford and Cambridge Universities. In it, Smith argues that Austen is intentionally exploring the abstract moral nouns her titles reflect and that even her other novels, like Emma and Mansfield Park, explore moral abstractions, like influence versus interference in Emma. Thus he extrapolates the conclusion that Austen was intentionally a moralist. He contends this though she may not have vaunted her position by claiming such an elevated title for herself and though she may not have included moralization in her advice about novelizing in letters to nieces and nephews.  

In this energetic work, Smith's central arguments for Austen as a moralist are (1) what she says and (2) what she does not say. His central support is the influence of Aristotle and Shaftesbury--either by direct or indirect influence (studied and read or indirectly acquired)--on Austen's moral aesthetic.

What Austen says is that characters have qualities of "mind." This is defined by Smith as more than memory or cognitive construct. It is defined as a quality of moral aesthetics, an aesthetic found to have prominent place in Shaftesbury's writing. Some examples pointed out of Austen's reference to "mind" are: "delicacy of mind" and "bursts of mind" (Smith). Examples of this in Pride and Prejudice are:

presence of mind
superiority of mind
liberal-minded, just, sincere,
turn of our minds
narrow-minded, silly man;
delicacy of mind
absence of mind
her mind improved
serenity of a mind at ease
state of mind
illiberal mind (Pride and Prejudice)

What Austen does not say is that characters have mono or dual characteristics the way "Calvanistic" moralist writers who preceded Austen did (e.g., Johnson, Goldsmith and Hume (Smith)). In other words, Austen does not describe her characters by a single quality, like garrulous, nor by dualistic comparison of good versus bad characteristics, such as mean versus generous or virtuous versus immoral. She describes her characters in an Aristotelian model by comparative degrees wherein one is nicer compared to another or one is more sensible compared to another (Smith).

Smith posits that (1) since Austen wrote from a "deep interest" in questions of a serious nature, "about human nature and human conduct" according to an Aristotelian model, she is therefore a moralist; (2) since she wrote in moral aesthetic agreement with the moralist Shaftesbury, who discusses qualities of "mind," there was informed intention in her moralizations.

One textual example of these moralizations is a comparison between Darcy's good will and Wickham's good will. Darcy's good will toward Elizabeth and her family regarding Kitty is sincere and genuine with no self-serving motives. Wickham's good will toward Elizabeth is nothing but self-serving manipulation. Darcy's actions on Elizabeth's behalf are "genuine good will," while Wickham's actions are "power [and] conceit" (Smith). As a moralist, Austen draws this moral picture on her "bit" of "ivory," "two inches wide."

"I have no right to give my opinion," said Wickham, "as to his being agreeable or otherwise. I am not qualified to form one. I have known him too long and too well to be a fair judge. It is impossible for me to be impartial." (Pride and Prejudice)