Who is the narrator, can she or he read minds, and, more importantly, can we trust her or him?
Third Person Omniscient
There are omniscient narrators, and then, there are omniscient narrators. And the narrator of Adam Bede is the second—as omniscient as omniscient gets. Seriously people, this narrator drops references to the history of Methodism (37.4) and Dutch paintings (185.17) the way some people drop "ums" and "likes" and "yeahs."
This narrator—this narrator!—can get into anyone's head. We get to see Mr. Irwine's intellectual life, but also get a bird's-eye view of the local schoolteacher's dog,
[…] whose affections were painfully divided between the hamper in the chimney corner and the master, whom she could not leave without a greeting. (248.21)
This is more omniscienter than omniscient. It's the omniscientest! And Eliot needs an omniscience-meister like this to help her deliver a chronicle of an entire community. Adam Bede is all about the knotty connections between different social classes. So you need a narrator who knows how a variety of characters—upper-, middle-, and lower-class—think. On with the omniscience.