"Europe gives the impression of being aged and weary,feeling less and less a protagonist in a world which frequently looks on itwith aloofness, distrust and even, at times, suspicion…As a grandmother, no longer fertile and lively," he said.
"The great ideas that once inspired Europe…seem to have been replaced by the bureaucratic technicalities of Europe's institutions."
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Speaking at the plenary session of the parliament, he told lawmakers that they had the task of protecting and nurturing Europe's identity "so that its citizens can experience renewed confidence in the institutions of the (European) Union and its project of peace and friendship that underlies it."
Pope Francis' visit to the European Parliament is the first by a pontiff since Pope John Paul II's visit in 1988. He is also visiting the Council of Europe – the region's human rights body - later on Tuesday.
"I encourage you to work so that Europe rediscovers the best of its health," he added.
The pope also spoke about the importance of education and work. On the question of migration, a hot topic in Europe, Pope Francis said there needed to be a "united response."
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"We cannot allow the Mediterranean to become a large graveyard," he said, referring to the number of migrants who die during their attempts to cross the sea and reach Europe.
"Rather than adopting policies that focus on self-interest which increase and feed conflicts, we need to act on the causes (for migration) and not only on the effects," he added.
Introducing the pope, European Parliament President Martin Schulz said that "over the past six years, Europe has seen a dramatic, unparalleled and unprecedented crisis which has had serious after effects."
Schulz said he recognized that there had been a loss of confidence in national and European institutions.
"This loss of confidence is tremendous and without thatconfidence and trust, no institutions can persist on a permanent basis. The cooperation of everyone is needed to regain that trust," he added.