What does fundamentalists, modernists, and athiest mean in this book?

The fundamentalists would be represented by the majority of the townspeople. They believe in the literal interpretation of the Bible.

The modernists would be the in other parts of the country who are willing to entertain new ideas and theories.

The atheists are those that believe the Bible is wrong, thatbitbis just story. Bdrummond calls the story of Genesis "pleasant poetry" in one part, but this group is better represented by Hornbeck, since Drummond proves to have some faith by the end of the play as hE symbolically places the Bible and Origin of the Species in his briefcase side by side.