MADRID » Pope Benedict XVI denounced the profit-at-all-cost mentality that he says is behind Europe’s current economic crisis as he arrived in hard-hit Spain on Thursday, and said morals and ethics must play a greater role in formulating economic policy in the future.

Benedict made the comments as he traveled to Madrid for the Catholic Church’s World Youth Day, a weeklong Catholic festival that is taking place against a backdrop of the European debt crisis and social unrest among the young that exploded recently in the riots in Britain.

Benedict said the crisis and sense of desperation among young people proved that ethics have been increasingly left out of formulating economic policy at local and international levels. He said: "Man must be at the center of the economy, and the economy cannot be measured only by maximization of profit but rather according to the common good."

"The economy doesn’t function with market self-regulation but needs an ethical reason to work for man," he told reporters traveling aboard the papal plane. He said the current crisis shows that a moral dimension isn’t "exterior" to economic problems but "interior and fundamental."

Benedict explored the theme more fully in his 2009 encyclical "Charity in Truth," in which he called for a new world financial order guided by ethics, dignity and the search for the common good.

Benedict arrived in a cloudy Madrid to a boisterous welcome from young people with their faces painted the colors of the Spanish flag chanting: "These are the pope’s young people!" A cordon of youngsters decked out in faux Swiss Guard uniforms greeted Benedict on the tarmac at Madrid’s Barajas airport, along with Spain’s King Juan Carlos and Queen Sofia.

Socialist Prime Minister Jose Luis Rodriguez Zapatero and conservative opposition leader Marian Rajoy, the man forecast to take power in November elections, were also present.

Clouds and a breeze kept Madrid’s notoriously hot August temperatures down to a relatively comfortable 25C (77 Fahrenheit).

This is Benedict’s third trip to Spain as pope, cementing its reputation as ground zero in his campaign to reinvigorate the faith in European countries where Catholicism has fallen by the wayside. Laws passed under Zapatero allowing gay marriage, fast-track divorce and easier abortions have deeply angered the Vatican, which sees the once staunchly Roman Catholic country as a battleground for the future of the faithful in Europe.

Many Spaniards have balked at the cost of the visit at a time of economic difficulty for many. Spain has a nearly 21 percent jobless rate, the highest in the eurozone.

Hours before the pontiff’s arrival, riot police and protesters opposed to his stay clashed in downtown Madrid. Police said eight demonstrators were arrested and 11 people were injured in the disturbances Wednesday night in the city’s Puerta del Sol plaza.

On Tuesday, police arrested a chemistry student working as a volunteer for the pope’s visit on suspicion he was planning a gas attack on protesters opposed to the pontiff’s visit, officials said. The 24-year-old Mexican student, identified by the Mexican Embassy in Madrid as Jose Perez Bautista from Puebla state, was expected to appear in a Madrid court Thursday.

Organizers expect a million or more young people from 193 countries to attend the festival.

The main events are a prayer vigil with the 84-year-old Pope and outdoor sleepover for pilgrims Saturday night at a sprawling air base, and Mass there the next morning.

In Spain the church faces a congregation for whom being Catholic is more a birthmark than a way of life. A poll released in July says that while 72 percent of Spaniards identify themselves as Catholic, 60 percent say they "almost never" go to Mass and only 13 percent every Sunday.

Except for a trip Friday to a historic monastery in El Escorial, 50 kilometers (30 miles) northwest of Madrid, the Pope will spend the whole visit in Madrid, meeting with young people, hearing confession from some of them, riding through the city in his popemobile and greeting young nuns, seminarians and university professors, among other activities.