Cardinal Basil Hume: "Prophets always are out of touch"

In a new encyclical letter to the world's Catholics, released to coincide with his 20th anniversary, he said people should pause to ask themselves the true meaning of life.

Our Rome correspondent David Willey said the 150 page document - the Pope's 13th encyclical - was essentially a philosophy lecture.

In it, the Pope - who once taught ethics at a Polish university - summed up the predicament of ordinary believers wanting an answer to such basic questions as:

• Who am I?
• Why does evil exist?
• Is there an afterlife?

The Pope said the world had been sucked into a maelstrom of data and facts. He said many young people felt they had no valid points of reference.

BBC's Emily Buchanan: "Catholicism in Poland is as strong as ever."

The encyclical concluded that it was all the more necessary to look for a meaning in life, just as philosophers had done since the days of Confucius and Plato.

The Pope said the immense expansion of humanity's technical capability demanded a renewed and sharpened sense of ultimate values.

He said that at the beginning of the third Christian millennium it was vital that the most pressing issues facing mankind - the protection of the environment, peace and the co-existence of different races and cultures - should be the subject of dialogue.

He said such issues might find a solution if there was a clear and honest collaboration between Christians, other religious believers and those who may not believe but have at heart the renewal of humanity.

He said what the world needed was planetary ethics.

An encyclical, while not claiming the status of infallibility, is the most authoritative sort of statement made by a Pope.

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