On the way to St Patrick's Hospital, Dublin, I ask the taxi driver (male) what he thinks of the notion that men are under threat of redundancy because women don't need men any more in order to survive either economically or biologically. Aren't men terrified at the prospect of women becoming Amazons procreating via petri dishes? The driver looks at me in the rear view mirror with an expression that says "on what planet?" What men feel like that? And why? he wants to know. Anthony Clare, I tell him. Who's Anthony Clare? asks the taxi driver.

So it wasn't a scientific survey. However, the taxi driver has the questions right. Who is Anthony Clare? And why does he feel that men are so vulnerable?

"Phallic man, authoritative, dominant, assertive - man in control not merely of himself but of woman - is starting to die, and now the question is whether a new man will emerge phoenix-like in his place or whether man himself will become largely redundant," he writes in his seventh and latest book, On Men: Masculinity in Crisis.

I know from previous media exposure that Clare has jokingly worried about his penis size, does his own ironing and regrets having smacked his children. I know he likes women and prefers them as friends.

But what I don't know is this: why is this 57-year-old media-savvy psychiatrist so afraid of women's power?

At St Patrick's Anthony Clare greets me with a charming smile and a noisy bunch of keys (St Patrick's has a multitude of doors to be unlocked and locked again). He seems softer, less brash than in the past. His hair - which used to be black - is now peppered grey, which suits him. He has stopped dying it black, he later admits, because it was "too much trouble". He immediately begins apologising. Says he regrets that he criticised me in On Men: Masculinity In Crisis. The reference runs along the lines of "Holmquist is a talented and usually informed journalist yet . . . " Very condescending. Dare I say, patriarchal?

In his book, Clare takes issue with my view that lone female parenthood in general is still stigmatised because it is seen as a threat to the male status quo. Male policymakers refuse to give lone parents subsidised, high-quality childcare, thus forcing many single parents (mostly mothers) to remain in the home and thus dependent on the patriarchy, in the form of social welfare. There is a strong argument - backed by research - that most problems of single parenthood are caused by poverty, not the absence of a father.

Clare counters that one in three Irish children is born outside marriage, so how can there be a stigma about it? He disagrees that many of the problems of single parenthood are caused by financial difficulties and could be solved by getting single parents into the workplace. Quoting reams of research, he argues that the children of single mothers tend to have more problems not because they are poor, but because they don't have fathers.

"The decline of the traditional nuclear family represents one of the less recognised but arguably the most significant of all the threats to phallic superiority," Clare believes.

Along with the trend for the disposable Dad, we have a culture that sees maleness as an unhealthy state, Clare thinks. A century ago, in Freud's day, to be a woman - hysterical, depressed, lethargic and dissatisfied - was to be pathological, while men personified health. Women wanted to be men and experienced "penis envy", Freud believed.

Today, it is men who are envious of women. Men abhor women for their biological creativity, Clare thinks. "The very traits which once went to make us the men we think we are and would like to be - logical, disciplined, controlled, rational, aggressive - are now seen as the stigmata of deviance. The very traits which once marked out women as weak and inferior - emotional, spontaneous, intuitive, expressive, compassionate, empathic - are increasingly being seen as the markers of maturity and health," Clare argues.

Tellingly, Clare writes that "men know they need women, depend on them. But for some men, many men (all men?), the female fulfilment of adult male dependency is shameful, with its connotations of a return to infancy and helplessness. Such disgust varies from man to man. But what seems uncomfortably true is that men differ from other men only in terms of the extent to which they hold hostile and resentful views of women, and not in terms of whether they do or do not."

He seems so passionate in his arguments that one wonders if the book is actually a metaphor for something deeper - Clare's own late mid-life crisis, perhaps?

Despite the fact that he has revealed the inner selves of many celebrities in his BBC Radio 4 series, In the Psychiatrist's Chair, Clare does not pay back the debt by revealing himself in this book. His publishers were "uneasy", he says, because they felt the book was too heavily researched and referenced and did not contain enough personal material. Two years late (it was due out in 1998), the book was the subject of arguments between Clare and his publishers, who asked him to add heart to the book by inserting case histories of male patients. This he did, but there is still an emotional distance - masked by intellectual vibrancy.

There is one case history missing, for example - that of Clare himself. One-to-one, Clare has an evasive eloquence, an ability to use words in a tantalising way that keeps the listener hooked, while at the same time giving little of himself away. A verbal wizard and born performer, Clare loved English at Gonzaga in Ranelagh, Dublin. (If he had been a secondary student today, he wouldn't have had the points to get into medical school, he says.) On a bookcase behind his desk at St Patrick's hang the masks of comedy and tragedy. Is it true what I've heard, that Clare is a conservative, patriarchal male behind a liberal, warm, media-friendly mask? "I think I am a typical confused male, a man who is coping with immense change," he says.

What is he confused about?

"What's the point of an awful lot of what I do. I'm in my 50s, I think one should be spending a good deal of your time doing things you want to do . . . and what is that? I want to see much more of my family and friends. I want to continue making a contribution, but how can I best do that?"

So, he is in a late mid-life crisis then. Pity it didn't make it into the book. The reserve would not let it.

Twelve years ago, Clare took a drop in income to return to the Republic and become medical director of St Patrick's Hospital, Dublin, after making his name as a media figure and as professor of psychological medicine and head of department at St Bartholomew's Hospital Medical College. Clare has maintained full caseloads of patients, while also running the hospital and until recently, teaching.

Psychiatry, he thinks, is as relevant as ever - nothing like the stereotype of the passive doctor listening without comment to a narcissist babbling about dreams on a couch. He sees himself as open-minded and "eclectic" - thanks to his training at the Maudsley in London - and he uses a bit of everything, including drugs, ECT and counselling. Not a bland psychiatrist, he confronts and argues with his patients when he thinks it's required. The only thing he has little time for is psychoanalysis, which he sees as a "flawed, secular religion" rather than a philosophy or science.

He is a rounded psychiatrist, then, but is he a rounded human being? "People who know me very well would say I have a lot of jagged edges . . . Sometimes I'm described in the media as urbane, but I'm not really," he says.