I’m re-reading Dune for the first time in 50+ years. The earlier part is a political intrigue story to which the science-fiction element is almost incidental. As a teen I read it as a heroes-and-villains story, but it seems to me now that I was reading that in: there may be valorous individuals, but none of the factions/parties are the Good Guys. An interesting theme is that our mental powers are far greater than we suppose, and are only held back by unwillingness to develop them.