Q: When we had our first child, his pediatrician encouraged "attachment parenting," and especially that we all sleep together. (We're no longer with that pediatrician, and our new one doesn't approve.) He's now 6 and this arrangement, wonderful at first, has since become very inconvenient for my wife and me. The problem is that he's terrified — not an exaggeration — of sleeping alone. If we put him in his own bed, he'll stay, but he screams like he's being attacked by demons. Otherwise, he's intelligent, creative and very confident. What can we do?

A: There are two basic types of fears: those that have some basis in reality and those that do not. The latter are products of the imagination.

If a homicidal maniac is prowling your town at night, breaking into people's houses, then a fear that he might break into yours is reality-based. If, however, no homicidal maniac is loose in your town, but you are nonetheless convinced that one is going to break into your house at night, then your fear is imagined. Obviously, your son's fear is of the second type. There is no reality that would justify his terror. If he sleeps by himself, in his own bed, nothing is going to happen to him other than he will be terrified; for a while, at least. That's important for you and your wife to understand.

You and your wife have not simply told your son that he is going to sleep in his own bed, period, because you are afraid something awful will happen to him if he is allowed to be terrified. You are afraid that he will be traumatized or lose trust in you or something along those lines. Your fear is not reality-based either. Your inability to confront your fear is preventing you from allowing him to confront his. This is known as a conundrum. As long as you are caught in this conundrum, you will not be able to help your son solve this problem.

You've probably talked yourselves blue in the face trying to convince him sleeping alone presents no clear and present danger. The problem is that you cannot talk a child out of an imagined fear. Said another way, an irrational thought is impervious to rational explanations. More talk will only turn your face bluer.

Your son needs to learn that his fantasies and reality are not one and the same. You cannot continue to sleep with him and help him learn this, nor can you talk him into this realization. You must stop sleeping with him, and you must do so cold-turkey. I've had the best results with the following method:

First, prepare yourselves. You need to convince yourselves that if your son becomes terrified at the prospect or reality of sleeping alone, that he will live. Furthermore, he will still be intelligent, creative and confident. In fact, he will be even more confident for having confronted his fear and lived to tell the tale. Needless to say, you and your wife must be on the same page about this.

Second, tell your son that his doctor has said that he can no longer sleep with you; that he must sleep in his own bed like other children. He can sleep with all of his lights on, he can even lie awake all night long, but he has to be in his own bed at night. Do not explain yourselves or try to get him to agree. Just tell him, and do so after supper on the first night of his new life so that he doesn't have a lot of time to build up lots of anxiety.

Third, put him to bed at his normal bedtime. If he says he's afraid, tell him that it's OK to be afraid. All children are afraid of something. You were afraid of things when you were a child, but you discovered, by yourself, that there was nothing to be afraid of. He's going to discover the same thing.

And let that be it. Leave his room. If he screams in terror (as he most certainly will), go back to his room every 10 minutes or so, look in (don't go in!) and say, "We're still here and all is well." Then leave and wait another 10 minutes. Do this on a night when you do not have to get up and go to work the next morning.

In the morning, remind him that he is still alive and that nothing that he imagined came true. Within a couple of weeks, this should be history. If you wait another year, it might take a month. Time's a wastin'!

Family psychologist John Rosemond answers parents' questions and includes his speaking schedule on his Web site at www.rosemond.com.