I've read about this phenomenon before as it concerns cats who were separated from their mothers and siblings too soon--it seems like it's a cat socialization-learning thing. Animals, just like human children, need role models for good behavior. So the only thing I'd add to Cary's answer is for future rescuers of abandoned kittens: consult a veterinarian EARLY about socialization issues.

If not, that would be my first suggestion. Intact male animals tend to be aggressive: it improves their ability to survive and pass on their genes in the wild, but makes it hard on any humans that try to share their own space with them.

If the cat was neutered - and still acts like this - then by all means the next step should be an animal behaviorist.

That totally makes sense about the lack of cat role models to teach proper behavior. (So if this cat is modeling your behavior, how scary are you and your spouse?)

After three years, cats don't adapt easily to change. But Cary is headed in the right direction.

Consulting a cat behavior expert is a great idea. You might also consider whether there is a veterinary college nearby where students might study and evaluate your cat, or for a small bribe accidentally have it end up in the disection lab (just kidding!!!) Seriously, the cat could be a great behavioral case study.

You can try a dog crate/kennel large enough for the cat and litter box. Cats sleep most of the day, so being in a crate could provide a safe territory for the cat to protect without terrorizing the entire house. A cover might be calming as well.

You can try cat videos on your television, much safer than exposing a real companion to FrankenKitty. Maybe by modeling cat behavior, the videos might calm the cat. (Use an old television in case it just enrages your little critter and it claws the screen.) My cat really loves watching other cats on my computer screen, then looks around back of the laptop to find out where they're hiding.

You can find a "cat lady." If she has 100 cats, she might be happy to take one more and it could thin the herd, doing her a favor. (Kidding again, couldn't resist).

If that doesn't work, try an extension office or co-op or some other organization that works with farmers or rural residents. It is not right to dump a cat on a rural road, but there may be some animal rescue program that could help find a home that could use a very aggressive cat to keep mice and rats out of the barn.

In the end, I do not feel that putting the animal down is morally weak, if the cat is suffering from its inability to bond with anyone or anything. This is not a good life for you or it.

I had a friend who let a girlfriend move in -- and celebrate the event with a new cat. The girlfriend left three weeks later and my friend ended up with a psychotic cat for 24 YEARS. Every time he got on the phone the cat screamed. Whenever he invited anyone over, the cat turned into a tiny cougar. My friend has Asperger's, so the lack of human companionship and the cat's lack of affection worked out OK, but it sounds like you need a life.

Humane society or animal rescue folks can help you through this. They are very level-headed about when cats can and can't be saved, and it has more to do with behavior than physical health.

Do your level best. That's all you can do... and remember, without you the cat would have died three years ago.

We had a similar problem, the one real variable being that we have kids. In the end, the threat he posed to our infant daughter made us choose euthanasia, after we'd exhausted every other option. Once you have an aggressive animal, no one wants to take him.

Cary's advice is only for the truly patient with the best of hearts. Best of luck to you.

This is a BBC show that is run on Animal Planet every weekday morning at 8:30 a.m. It's like a Nanny 911 for pets. It may give you some sense of optimism that this problem can be solved with the services of a behavioral consultant. Barking Mad works with all of them--dogs, cats, ducks, geese, overly aggressive turtles and overly shy hampsters. Not all problems can be solved, nor will your cat necessarily become the pet you want him to be, but you could end up with something slightly less awful.

I'm already willing to bet that this has something to do with the cat's sense of his territory. Dogs are all about hierarchy; cats are all about real estate. Read a book called "the Tribe of Tiger" if you want to get some sense of why the cat brain is wired this way. Your cat may need his own "space," i.e., some sort of rearrangement of your apartment/house or the way you use it so that he feels there is some area that he can effectively protect from territorial incursion. It may well be that your living space is too small for him, in which case a farm may be the best answer, but you'll never know if you don't check it out.

For those of you who insist that cats can't be trained, actually, you can find any number of professional animal trainers who insist that cats are easier to train than dogs. The key is to understand that you have to make them want to do something; unlike dogs, they're never going to take orders from you just because you're the alpha male, because, again, they don't respond to hierarchy in that manner.

Certainly have him neutered first, if he hasn't been. Find a cat behaviorist. And consider medication if that doesn't work.

But sometimes there is no kind way to let an animal live in our world.

I'm a senior volunteer at a no-kill shelter; I work with the dogs, but adopted my own cat there. The terrible secret of no-kill shelters is that it's an impossible goal. Sometimes animals must be euthanized for reasons of physical health, when their quality of life cannot be made tolerable with the full effort of a very good veterinary hospital.

But sometimes a dog--and yes, sometimes a cat--while we work with them to try to socialize them and make them happy and safe to live with, can't adapt. If we have a dog that we realize can't be trusted not to bite, unexpectedly, and through no blame of its own (something in his experience or brain tells him it's the thing to be done, and you can't always even tell if it's nature or nurture): that's a dog we can't adopt out.

And it's true for a cat, too.

Two or three years ago an article in the New Yorker recounted the author's tragic history with a little dog she'd adopted from a rescue. It turned out the rescue knew the dog was unpredictable and dangerous--it seemed to have neurological issues, and would even, horribly, attack itself--but didn't tell her. She, of course, loved the dog, who could be very sweet when not wrestling his demons, and tried everything, absolutely everything, all kinds of trainers, medicines, everything. Even as it injured her, injured visitors, injured her partner.

Whatever had gone wrong in this dog's brain turned out not to be fixable. It was only when she realized the dog was as unhappy, living in what must have been to its perceptions an unrelentingly hostile world, that with much mourning she let it go.

If you end up having to do the same, it's a small, real tragedy; and not your fault. I hate when we lose a dog at our shelter, but I know we do everything we can before concluding the dog can't live happily and safely with humans (and there aren't other options--we used to send some to a very crowded really-truly no-kill shelter but the conditions became too inhumane; see the documentary "Shelter Dogs" for footage of the miserable animals trapped in stereotypic behaviors like eternally pacing in small circles: like that: not an option).

Your cat isn't content and at home in the world. Give him a chance to learn to be. But be prepared to let him go if you have to.