Portside

If “Captain Fantastic” doesn’t cram all of human experience into that box we like to call the dysfunctional family — a category that suggests that all anyone needs to get through Thanksgiving is therapy talk and a group hug — it’s partly because its characters have politics, not simply feelings. The Cash children stumble, but they’re supremely capable and self-aware. What makes them unusual isn’t their knife skills; it’s that they talk seriously about ideas.