For Brazilian performer and teacher Angela de Castro, the honesty involved in playing the clown is not only therapeutic, it also has a spiritual dimension.

Angela de Castro looks at me, and there's nowhere to hide. Luckily I've a few props - a notebook and pen - so everyone knows I'm not really here. Not really participating in a clowning workshop.

Its title is 'How to be a Stupid' - no great difficulty there, you might think. But something about the language she's using, like "risk", "vulnerability", "honesty", suggests this is going to be a challenging week. The others seem undeterred; they've even taken off their coats. All performers - some established, some neophytes - they've come because they remember de Castro's irresistible stage presence six years ago at the Dublin Theatre Festival, in Snowshow with Slava Polunin.

Offstage, her charisma and wit are evident too, and they triumph over the sludge-green and cream environs of Archbishop Byrne Hall on a nippy Monday morning. As she speaks in her heavy Portuguese accent, telling the story of her journey from her native Rio, Brazil and her discovery of clowning, she bounces on her feet, her arms outstretched, brown eyes wide.

De Castro is here at the invitation of The Temenos Project, the Dublin-based inter- disciplinary organisation, which is running a series of workshops and masterclasses over the coming months. Visiting artists and teachers from home and abroad will explore aspects of dance, drama and music in short residencies, some aimed at professional performers, some open to everyone. De Castro's second five-day workshop, which starts on Monday, will be open to non-performers, and on Saturday she will host a 'Play Day', a day of games and fun (for adults).

Playing is what de Castro does best and what she wants to enable others to do. Whether on stage, or devising work with directors of theatre companies as a clown consultant, or at the Why Not Institute she founded as part of the Arts Ed Institute in Chiswick, London, she wants to express the gullible, innocent aspect of human nature. Because this work is personal and revealing, what happens in the workshops is confidential. Exit journalist, thankfully unexposed.

At the end of the first day, de Castro is fired up by the group's response. What happens in the workshops, she says, is a process of exploration. She is teaching a set of skills and also promoting increased self-awareness, developing participants' enthusiasm and charisma and allowing them to express their unconscious, or sides of themselves that are usually hidden or suppressed. If this sounds like a therapeutic process, that's because it is.

"We are peeling off all the layers of defence. The masks we wear - they all have to go," she says. One exercise is to ask each person to walk into the room and look directly at the audience, to make strong eye-contact. "There is no fourth wall for a clown; we look, we are open."

Whether she's teaching performers or, as she increasingly does, business people, teachers and therapists, her training method is the same. The aim is to reach "the state of clown". "This is the imaginative state and this is the beginning of everything. Each day we work with our gullible side, the part of us that is funny, crazy. Everyone has a clown and I help people to find their own clown," she says. "Clowning is a very individual thing and must be developed in solitude. I know that I have a calling, but I have to hear that call in solitude. Clowns are like angels; both bring a message, and are a message. Both are so pure, they are a link between heaven and earth, between the divine and the human."

This spiritual interpretation of her work is shared by Temenos director Marty Boroson. "It's a sacred thing that she's doing," he says. "It has enormous depth. She's finding the fool and helping bring that fool into reality. She lives for this state of innocence and truth."

For de Castro these workshops, which she gives all over the world, are just the beginning. She emphasises the importance of solitude and self-awareness in the development of clown work.

Her own preparation took five years and began by accident. When, after some years trying to find her path as a performing artist in Brazil, de Castro stumbled on a clowning course in London, she immediately changed her plans and seized the opportunity.

"This was the happiest time of my life. I knew I wasn't alone any more. I had found my family. And, because I couldn't speak, not knowing any English, I had no past. It was an opportunity to start again, a rebirth," she says.

Being a beginner is her ideal state: what she wants to teach is not knowing, not being competent, not being an expert - a Socratic pedagogy. Her opening remarks to the workshop group are: "I don't know any more than you do. I just know different things."

"When I'm teaching teachers, I focus on learning and on failing," she says. "How can you learn if you don't fail? We have been educated to be clever, to succeed, not to be a loser. But clowns are not clever. In order to be open, you have to allow yourself to fail. When you can laugh at failure, yours or others', it gives you another perspective on your own problems."

"Try again. Fail Again. Fail better" - de Castro is echoing Beckett's words, and there's no doubt that her conception of her work chimes more with Beckett's clowns than with circus clowns. The term "clown" is often misunderstood, she thinks - "people abuse it; a juggler with a red nose is not a clown" - so she tends to call herself a performer.

IF CLOWNING is a mask, it is one which, paradoxically, allows the essential self to shine through. Pathos, poignancy, fragility, naivety, wistfulness, openness, honesty - these are the characteristics of the clown, drawn from the rich traditions of the Elizabethan fool, the court jester, the commedia dell'arte clown, the white-faced Pierrot of the Harlequinade - and re-animated by Charlie Chaplin and Fellini. The legacy was formally revived and refined in the 20th century by Etienne Decroux, mime masters Louis Barrault and Marcel Marceau and, above all, by Jacques Lecoq, whose school in Paris has had a formative influence on British companies such as Théatre de Complicité and Told By An Idiot and, in Ireland, on Barabbas.

Between workshops, de Castro is developing two new shows, one celebrating the fools and clowns in Shakespeare, who, in Only Fools, No Horses, will meet up in a theatrical no-man's land, and, using movement and music, will tell their stories and give their own versions of the dramas. My Life is Like a Yo-Yo, an autobiographical piece, will present de Castro's journeys, "geographical, spiritual and personal".

"It will be about transformation," she says. Like all her work.

'How to be a Stupid', a workshop open to everyone, runs from Monday to Thursday, from 10 a.m. to 6 p.m. at Archbishop Byrne Hall, Synge Street, Dublin 8 (price: €225).

A 'Play Day' will be held on Saturday, March 9th, from 11 a.m. to 4 p.m. (price: €25). Booking and details from The Temenos Project (telephone 01-635152 or e-mail admin@temenosproject.org)

My Life as a Yo-Yo will be performed at The Pavilion Theatre, Dún Laoghaire on May 29th and June 1st