The People's Economics

The hero has made his money in what was considered an honourable way — the spoils of war. (The British government would give 'prize money' to naval officers for capturing an enemy ship). Being a naval officer had another advantage — it gave you a title. In the book anyone who is just plain Mr., who might make their money by trade, is looked down upon. Another thread in the book was making sure that an old friend of Anne, a Mrs Smith, got the income due to her from her property. But that property was in Jamaica, so presumably the income came from slaves. That was seen as a perfectly reasonable way of getting an income.