One book I took to read on holiday was Robert Musil's The Confusions of Young Törless, which I recommend. I always like novels that discuss Kant explicitly, as this one does. It has been compared to Lord of the Flies, but it's at least as much like The Brothers Karamazov, with the crime being (extreme) bullying rather than murder. The root of the problem, as it seemed to me, is not the absence of adult authority figures but the absence of any reason to believe in conventional, traditional ideas about how to behave. It is pretty much taken for granted that Christianity is out of the question, and the uninspiring figures of the teachers at the military academy where the novel is set are like the opposite of an advertisement for conventional morality. These are the people you are supposed to look up to, this is what it is promised you will become if you do as you are told. And they are weak, dull, and rather poor. (Musil doesn't go into this, but part of the problem here might have to do with capitalism as much as it has to do with the death of God.) So the boys look for something else to believe in.
Törless is bothered by the limits of reason. He has a longish and disappointing conversation with his mathematics teacher about imaginary numbers, how much we don't know or understand, and how much students are asked to take on trust from their teachers (who, he finds out, themselves do not know all the answers). If reason is limited then not only is there room for faith, as Kant says, but there is a need for faith. But faith in what? Here's where writing about a book that you read two weeks ago in an airport becomes a problem. I don't remember which character is which, and even at the time I found myself forgetting who was being described. So I'll just speak vaguely. One of his friends, I think, has a roughly Schopenhauerian belief in some sort of Indian mysticism. For this mysticism he will overstep the bounds of conventional morality, and because of this mysticism he sees no reason not to do so. Life is little more than a dream, after all, as Schopenhauer sees it. The other one (again: I think) is more 'Nietzschean,' in the crude, will-to-power, master morality sense. He's a bully, in short. The result is bullying, of course. The all-male environment of the military school perhaps encourages the kind of contempt for weakness that goes with this, and the sexual desires of the boys have no outlet except with an understandably cynical prostitute or else with each other. So the bullying takes on a sexual aspect, although it's not really clear (to anyone, I think) how much of it is really gay and how much is merely sensual. One of Musil's points seems to be that this kind of distinction is inherently vague. In fact he suggests at times that everything is inherently vague, which I suppose is a more or less Kantian or post-Kantian thing to think.
If a story has an ending (happy or sad) then there isn't much of a story to the novel. The victim of the bullying goes away and Törless learns nothing much. All that is definite, determinate, fixed, intelligible is concrete things, things with names. But all that really matters exists in a different, psychological (I'm not sure that's the right word) realm, which can never really be understood or articulated. So the twin temptations are into nonsensical mysticism, or something like it, some kind of irrationality, on the one hand, and into a desperately conventional materialism, on the other. (Between the two is the skin, and a third option would be to focus on one's own physical sensations in an infantile and masturbatory way, like Leo Wojtys in Witold Gombrowicz's Cosmos.) Musil offers no solution.
Perhaps Wittgenstein offers a kind of solution, insofar as his work is a response to Kant or the post-Kantian condition. I don't know how to articulate what this solution might be though. Something like the gradual disappearing of the apparent problem, perhaps. Apparent dilemmas cease to be apparent, not once you apply the conceptual scheme of phenomena and noumena, but when you think out the supposed problem and its terms.
Another kind of solution might be provided by art, to the extent that it can give some expression to the inarticulate chaos of the psyche. The other book I read on vacation was Geoff Dyer's Otherwise Known as the Human Condition, in which Dyer suggests that although poetry might be impossible after Auschwitz, photography might take its place. If this is true then the best advice might be don't speak (or think) but look. This also, of course, has a Wittgensteinian flavor.