The French philosopher Pascal put forward the theory that "most of our troubles in life come because we do not spend a small part of every day alone in our rooms." It is a view the monks of Holy Hill Hermitage in Co Sligo try to impress on their visitors.
At 8 p.m. the period of "grand silence" has begun in the main house and in the small hermitages dotted around the Sligo hillside. You are asked to try to keep noise levels to a minimum after this time, even when doing such tasks as washing dishes.
In your one-room hermitage the only sound is your footsteps on the tiled floor. You realise you feel lost. There are no distractions. Minutes pass very slowly and the evening stretches ahead.
Through one window you can see the light of another hermitage across the fields, through the other, the swaying branches of tall trees. As you pull the blinds it is a little eerie.
Inside the stone hermitage it is modern and beautifully finished with wood panelling. There are chairs, a bed, shower and toilet, kitchen sink small fridge and a single-ring stove. The bookshelves are filled with spiritual readings from Christianity and other religions.
As you eye the mobile phone you contemplate breaking your pledge not to turn it on to call a friend, and begin to see that being a hermit would take some getting used to.
The monks at Holy Hill in Skreen admit that theirs is "a rare vocation". There are just 20 members of their congregation worldwide, between houses in the US and Ireland. Apart from one Irishwoman, they are all from America.
The order is highly unusual in the Catholic Church as a community of apostolic hermits, with men and women living together. The Spiritual Life Institute was founded by Father William McNamara in 1960 with a mandate from Pope John XXIII. The monks live "a vowed life of solitude in poverty, celibacy and obedience", in the tradition of the early Carmelites on Mount Carmel. They also see themselves as keeping the Celtic monastic tradition alive.
A number of houses were established in the US and Canada in places of wilderness where the monks and those on retreat could have a "desert experience".
They came to Skreen in 1995 at the invitation of the Bishop of Killala, Dr Thomas Finnegan, and are based at Carrowcullen, a former landlord's house occupied by the Sisters of Mercy from 1921 until the early 1990s.
In their brown and cream ankle-length habits, they now take their walks in the marshy, green hills near Ladies' Brae at the foot of the Ox Mountains.
Mother Tessa Bielecki, the first to join Father McNamara in the institute, says their way of life is in keeping with the church tradition of hermits living in a loose-knit community. In this way, she says, it is possible to "test the authenticity of your solitude" and be sure it is not merely a selfish escape.
The monks spend some days every week in total solitude - and at times of retreat a full week or longer. "If we come out of a week of solitude and are not more generous and loving to each other, then that solitude is not for the sake of others." However, time spent alone is seen as vital. "If we are going to grow in relation with God, we need to spend time alone with God." When people come on retreat with problems she asks them when they last sat alone.
They emphasise that their way of life is not an escape from reality, but a way of living a fuller life. Through going out to give retreats and inviting people to the hermitage they help others to incorporate this philosophy into their own lives.
Mother Tessa says the periods of solitude are when they "fill up" and then the fruits of that are shared with others. "Our role is to help feed people's spiritual hunger," she says.
A major building programme since 1995 has transformed Carrowcullen. Derelict courtyard buildings have been renovated and now house a chapel and living quarters. A number of small stone hermitages, designed to fit in with the landscape, have been built at locations spread around the 28-acre estate. Longterm plans include a library and retreat rooms.
Much of the work is done by the monks themselves. They believe in the importance of manual labour and also of regular physical exercise. Morning prayers start at 6 a.m., although they usually get up at 4 a.m. They eat alone apart from two communal meals a week, and are vegetarian except when given gifts of meat.
To have men and women living together in a community like this has been unheard of for centuries in the Christian churches. Mother Tessa says she believes it is the religious life of the future and that it works because of celibacy. "There is a fullness and a wholeness when there is a man/woman dynamic. Both have something special to offer."
There is an earthiness about the monks not usually associated with the religious in this part of the world. The women all wear their hair very long beneath brown head-scarves, the men all have beards. They look at home as they go about their jobs in the wet farmyard.
Their Christmas celebrations are also somewhat unorthodox. After more than three weeks of solitude, tonight they will light a bonfire at a chosen spot and celebrate Midnight Mass outdoors. Then they will share a meal sitting around the fire and return home in the early hours.
The only Irish member of the congregation, Sister Nora Tunney, says she was drawn to the life after meeting Father McNamara in Dublin in 1991. Before then she questioned what life was about but joining the institute "felt like coming home".
She exudes cheerfulness. "If this life brings a person to the fullness of life, if it gives them vitality, then it is for them." She believes the time she spends in silent prayer has an impact on the world. "If I didn't believe that, I couldn't be here. Everything we do affects the world."
HER day begins at 3.30 a.m. She loves "the sense of mystery in the dark mornings" and says that while she knows others find her life unusual, she doesn't. "I work in the garden, I make bread - to me it seems so ordinary." Father William McNamara, now aged 73, has decided to make Skreen his home for the rest of his life. He spends a great deal of time in solitude. Suffering from pains, he moves slowly and speaks softly, but smiles frequently as he talks about his life. He says he went into solitude "to be with everyone, to become endowed with powers from on high so I could have something of importance to say".
He stresses the importance of humour and joy and of living life as "a passionate adventure", but says he has worries about the modern world.
"I become more concerned about the excessive noise, especially talking noise. The fewer words we talk, the more we become dominated by God."
People can spend up to a week at Holy Hill, although places are limited because of the number of hermitages available. The monks believe in giving "a minimum of direction" and it is up to those on retreat to decide if they want to join in communal prayers. Accommodation costs are minimal, although the monks are in need of funds to help pay for the extensive construction work.
Holy Hill is also open to the public one Sunday per month, and locals are encouraged to come for Mass and to bring food for a communal picnic.
A stay at Holy Hill is far from easy. The transition from a life where there are constant distractions and very little time for self-examination is difficult. Most people who stay say it takes a couple of days to settle into the experience.
Mother Tessa accepts that at the beginning many people find it difficult to be alone. "You learn a lot of things you don't like about yourself. It can be very painful. But we are naturally spiritual if we are living the right kind of way. If we sell out to modern life and its frantic pace, then we lose our souls."