Thanks for all the comments about Narnia. I'm into the third book now. (The Horse and his Boy) One slightly disturbing aspect is a racist undertone. I say "slightly disturbing" because, unfortunately, it was all too common in books of that era. The hero of the book is a young Narnian boy who was shipwrecked as a baby in the southern empire of Calormen. The Calormenes are described as haughty, cunning and cruel. And swarthy of skin.
"This boy is manifestly no son of yours, for your cheek is as black as mine but the boy is fair and white like the accursed but beautiful barbarians who inhabit the remote North."
There is also the militarist angle which showed up in the other books, a playing out of the good vs. evil dualism implicit in Lewis' version of Christianity.
But it's a literary angle that I'd like to blog about; I find it irresistible to compare Lewis' Narnia to Tolkien's Middle Earth. The two men knew each other, were in fact close friends and members of an informal literary society called the Inklings. They would read manuscript chapters to each other and no doubt influenced one another's thinking. There is some obvious similarity of both style and substance (although it is only fair to compare the Narnia books to the Hobbit so far as style goes - both being intended for the young.)
One striking difference is the much higher degree of verisimilitude and internal consistency in Tolkien. The Narnia stories I've read so far show a lot of quite loose continuity. For example, in the Lion, the Witch and the Wardrobe much is made of the visiting English children being "children of Adam and Eve" and the various talking animals, satyrs and nymphs of the world apparently regard humans as quite an oddity.
Now, in the Horse and his Boy, there seems to be a whole race of (beautiful white) Narnian humans amongst the other creatures.
Also, the geography of Narnia is sketchy at best, and there is certainly no attempt at developing languages or real histories for the various races. Tolkien's world, on the other hand, was worked out in painstaking detail. In fact, Tolkien was a linguist and his first creation in the oeuvre were the languages of the elves and Numenoreans, which he did as an exercise in linguistic structure. He then began speculating about what kind of people might speak these languages, and worked up the SIlmarillion as a result. The published books came later, and were fitted into a pre-existing history and geography.
Narnia, on the other hand, seems almost an afterthought. A colourful backdrop for fairy stories with a Christian message. Tolkien too, was a Christian, but his message is much less overt (and perhaps even less orthodox and more pagan in spirit.) Some critics of Tolkien have indeed charged him with not including a religion for his world. This charge seems to me totally unwarranted. The men and elves of Middle Earth were so close to the gods (the Valar) that no formal religion was needed.
Changing gears a little, it's also occurred to me to wonder whether the Narnia movies coming out just now aren't possibly a Christian counter-stroke to the success of the Harry Potter books.