Here I would like to talk about "where I'm coming from when I speak of slavery.
A good deal of what I have read about slavery has come from my study of Charles Darwin, his Voyage of the Beagle, and his trip across and through the slavery-ridden South America of the mid-19th century (as well as his letters and diaries). (This for my Advanced Writing in the Natural Sciences classes.) Reading about Darwin, as I have said before, teaches one much about Austen. Darwin comes from the same class as Austen, and he is like Austen in numerous ways (the atmosphere of his family life, the clergymen all around &c). Well, when he finally laid eyes on the slave trade and saw slavery in operation, he was appalled and horrified; the Wedgewoods, to whom he was related (his mother was a Wedgewood, he married a Wedgewood--his firstcousin in fact) were strong abolitionists and produced and sold a famous set of crockery on whose face was a suffering slave. Now Darwin tells us his dislike of slavery was theoretical, until he saw and experienced what it was. Then he loathed it. This is significant for Austen. It's why the slavery issue is background not foreground, as well as, the issue itself being kept to a minimum of detail in the novel (and one cut-off conversation which goes nowhere and is only reported). Here I will share one brief piece Darwin wrote (there are many about what he witnessed) and how he felt when he saw it for the first time:
"Near Rio de Janeiro I lived opposite to an old lady, who kept screws to crush the fingers of her female slaves. I have stayed in a hose where a young household mulatto, daily and hourly, was reviled, beaten, and persecuted enough to break the spirit of the lowest animal. I have seen a little boy, six or seven years old, struck thrice with a horse-whip (before I could interfere which I did) on his naked head, for having handed me a glass of water not quite clean... And these deeds are done and palliated by men, who profess to love their neighbors as themselves, who believe in God, and pray that his Will be done on earth! It makes my blood boil, yet my heart tremble, to think that we Englishmen and our American descendants, with their boastful cry of liberty, have been and are still so guilty."
There are other passage equally unforgettable.
One important difference between Austen and Darwin is Darwins were Whigs & not Tories. This means they were for reform. Darwin gets into terrific quarrels with the captain of the ship he is aboard because the captain is a Tory and justifies slavery. I'm not saying that because Austen was from a Tory family she or her family would justify slavery; her brother apparently disliked it and mentioned it. But I am saying that before we can infer an attitude by Austen we ought to have some explicit evidence.
Which gets me to my last point on slavery in Austen. I believe that when Austen wants to make a point she is not chary. She does not try to hide her meaning. She may be ironic, satiric in mode, but she wants us to understand her and when she is definitely against or for something we can call politically or socially abstract and large she makes it clear. Now these things are _rare_ in her books. Her books remain on the level of intimate moral perspectives and conduct. Still there is one place where the word slavery is used and strongly. It's in Emma. There we get an explicit, full-throated expression of the misery of the life of a governess; there there is a reference to the slave trade so that Jane Fairfax may say governessing is (to her) worse. It is a selling of the soul as well as the body. Again slavery may be found to be implicit in the depiction of the sources of Mrs Elton's brother-in-law's wealth, and again it is part of the background characterizing Mrs Elton.
In other words in Austen's novels when she wants to condemn something she's not afraid to make her condemnation explicit. I would say the issue of slavery is not uppermost in her mind or even strongly there because she does not bring it forth. Governessing is something she dreaded because it was what she was threatened with and saw in homes she visited. Here is a striking phrase from The Watsons: "Poverty is a great Evil, but to a woman of Education & feeling it ought not, it cannot be the greatest--(I would rather be a Teacher at a school (and I can think of nothing worse) than marry a Man I did not like" (1974 Penguin, ed MDrabble, p 110) This is Emma Watson--and Jane Austen. There is no comment on slavery equivalent to this in Austen; there are many such in Darwin--after he left England and encountered slavery for real. Not to say slavery is not used further to condemn the basis of the hollow amoral points of view we find a number of the characters in Mansfield Park embodying, and it is to say that Mansfield Park is one of Austen's darker books for this background of slavery. But we must be careful what we make of it. I have thought more important in the novel is the subject of money, of class, of the distinctions these make between the people, how these drive everyone to sell themselves or others and in Maria's case eventually be destroyed. Though don't think I'm too sympathetic there; Austen has presented her as someone who coolly drunk down her poison, and then made love to the employment of the money she got--until of course our villain-hero, Henry Crawford turned up in the room once more.