They're often bracketed together, Tolkien and Lewis, which I suppose is fair because they were great friends - both Oxford writers and scholars, both Christians. Tolkien's work has very little of interest in it to a reader of literature, in my opinion. When I think of literature - Dickens, George Eliot, Joseph Conrad - the great novelists found their subject matter in human nature, emotion, in the ways we relate to each other. If that's what Tolkien's up to, he's left out half of it. The books are wholly male-oriented. The entire question of sexual relationships is omitted.