"Some people are no longer able to bear silence and solitude for very long," he said during a vespers service at a Carthusian monastery in Serra San Bruno in Calabria.

Monasteries remind people of the need for silent reflection, which lets people delve into the apparent emptiness of solitude and experience real fullness, that is, God's presence and true reality, he said.

By spending time alone in quiet prayer, people find life's essentials and unity with others, he said.

The pope spent one day in the Diocese of Lamezia Terme in southwest Italy -- a region still struggling with organized crime, corruption and high unemployment.

During an outdoor Mass, the pope called the region a "seismic territory, not just from a geological point of view" but also because of the upheaval caused by negative social and behavioral patterns.

"It's a land where unemployment is worrisome, where often ferocious criminality tears the social fabric, (a) land in which there is a constant feeling of being in a state of emergency," he said in his homily.

"Don't ever give in to the temptation of pessimism and turning inward," he said, urging those gathered to use their faith in God to foster collaboration, help others and promote the common good.

Monasteries are indispensable for society because they remind people of the need to put God and the common good before self-interest, he said after the Mass.

Today's societies are not healthy; the air "is polluted by a mentality that is un-Christian and inhumane because it is dominated by economic interests, concerned only with earthly things and lacking a spiritual dimension," the pope said.

Not only is there no room for God, but other people and the common good no longer have a place in society, he said.

"Rather, the monastery is a model of a society that puts God and fraternal relations at the center," something "we really need in our day, too," he said.