Individualism in Moby Dick.
Robert Shulman uses concepts from Philip Greven's 1977 book "The Protestant Temperament" to argue that Evangelical Protestants suppress their will and desires to subordinate themselves to God's will. In his view, this can create a lot of anger and hatred that can be hidden or directed outward at others like enemies, blacks, foreigners (these days, it would be illegal aliens), American Indians, or the White Whales of conservative Christian culture like gays, Muslims, and liberals. Shulman explains that this is why Captain Ahab has so much anger to direct against Moby Dick, and uses his individualism to fight for metaphysical goals, not material goals (581). In my view, there may be Evangelicals who feel angry about having to do God's will who direct that anger against others that they demonize, but in my view they are not what one would consider "true believers" because a true Christian would rely upon the Holy Spirit to help him want to satisfy God's will, and this happens without creating anger or hatred. Furthermore, it is Christ who admonished us to love our enemies (Matthew 5:44) and not to kill others (Mark 10:19).
According to Rita Brown in Novels for Students Vol. 43, Melville was brought up, in the Dutch Calvinist Church, which taught that God predestined every detail of everything that will happen on earth, making it a puzzle why God would allow evil things to happen as well as good things (151). Melville left the Calvinists for the Unitarian Church, which didn't have any simple answer to the problem of where evil comes from. Melville was pessimistic about the world like his other romantic writer peers such as Nathaniel Hawthorne and Edgar Allen Poe.
Shulman indicates that in Melville's novel Moby Dick, he questions traditional answers about where evil comes from. Captain Ahab is portrayed as an ungodly man who often considers himself to be godlike in his power and lords over his crew as if he were their creator.