Modernist ambiguity, or realist emotional ambivalence, is unknown to Tolkien—the good people are very good, the bad people very bad, and though occasionally a character may be tossed between good and evil, like Gollum, it is self-interest, rather than conscience, that makes him tip back and forth. Betrayal and temptation happen; inner doubts do not. Gandalf and Aragorn never say, as even the most patriotic real-world general might, “I don’t know which side I should be on, or, indeed, if any side is worth taking.” Nor does any Mordor general stop to reflect, as even many German officers did, on the tension between duty and morality: there are no Hectors, bad guys we come to admire, or Agamemnons, good guys we come to deplore. (Comic-book moralities, despite their reputation, are craftier; the “X-Men” series is powerful partly because it’s clear that, if you and I were mutants, we would quite possibly side with the evil Magneto.)
It’s okay not to like Tolkien — it really is — but what I find annoying is that so many of the people who criticize him do so by saying things that are manifestly untrue. It obviously is conscience that troubles Gollum, his awareness that Frodo is a “Good Master” who deserves to be obeyed or at least treated honestly. (Moreover, Gollum and Frodo are bound by a shared suffering.) While it’s true that Aragorn has no “inner doubts” about whether Sauron might be a nice guy after all, he is afflicted by many doubts about his own role in the story, his own fitness to lead. Boromir doubts the wisdom of the Council, and can’t overcome those doubts. The doubts of his father Denethor consume him and send him over the edge and into despair. And of course Gopnik has forgotten completely about Saruman, who at a slightly earlier stage in the story than the one told in LOTR proper was a leader among the Wise — along with Gandalf, Elrond, and Galadriel — before undergoing corruption.
It has just become the tale that middle-to-highbrow critics tell — ever since Edmund Wilson was saying his own manifestly untrue things about Tolkien in the New Yorker fifty years ago — that Tolkien’s fictional world is morally simplistic and rigidly Manichaean. It may be true that the story of the Ring is less morally ambiguous than the average realistic novel, but that’s primarily because Tolkien wasn’t especially interested in the problem of knowing right from wrong. His concern was to explore the psychology of the moment when you know right from wrong but aren’t sure whether you have the courage and fortitude to do the right thing.
Modern liberalism likes to think that all our problems are epistemological: we are afflicted by never knowing with sufficient clarity what we ought to do. Our fictions tend to reflect that assumption. Tolkien, not being a modern liberal, thought it more interesting to explore situations when people know what they need to know but may lack the strength of will to act on that knowledge. He might say, and with some justification, that contemporary literary fiction is not simplistic in regard to such problems but oblivious to them.