But what really throws me off is that, though you have people being scammed to greater or lesser extents (and, so far, the greater is not even all that great), it almost seems like Melville (via the omniscient narrator) is talking about the virtue of being trusting. That, it's better to be trusting and get duped than being cynical. A lengthy paragraph was given on Tacitus being a terrible thinker for his cynical views on humanity.
There is a wooden-legged man, who is very cynical towards anyone on the steamer (where the story takes place) who seeks charity and especially towards those that give the charity. At one point, meeting again a Methodist clergyman who he had previously mocked for helping a cripple (the wooden legged man assuming the cripple was faking it), he gets into a conversation with 2 other men who are more trusting towards mankind:
It's the man with the wooden leg who makes the bolded statement.“So I did, so I did; how unfortunate. But look now,” to the other, “I think that without personal proof I can convince you of your mistake. For I put it to you, is it reasonable to suppose that a man with brains, sufficient to act such a part as you say, would take all that trouble, and run all that hazard, for the mere sake of those few paltry coppers, which, I hear, was all he got for his pains, if pains they were?”
“That puts the case irrefutably,” said the young clergyman, with a challenging glance towards the one-legged man.
“You two green-horns! Money, you think, is the sole motive to pains and hazard, deception and deviltry, in this world. How much money did the devil make by gulling Eve?”
Not done with the book yet. Pretty enjoyable though Melville's writing in this book (compared to Moby Dick) is a bit run-on at times. Commas chopping up thoughts to inject sides that seem to muck up the flow of the narrative. But the dialog between various characters is really good in this book.