Pope Benedict XVI on Monday issued his strongest criticism yet of evolutionary theory, calling it "unreasonable".
Speaking to a 300,000-strong crowd in this German city, the former theological watchdog said that, according to such theories derived from Charles Darwin's work, the universe is "the random result of evolution and therefore, at bottom, something unreasonable".
The homily appeared to throw the Catholic Church's full weight behind the theory of intelligent design (ID) - a subject of massive controversy in the United States.
The Catholic Church has for over 50 years accepted Darwin's theory of random selection as the most probable cause of development, but has alway stressed God's role.
Recently, however, top theologians have clashed with Catholic scientists over so-called 'evolutionism' - that is, attempts to make evolution explain everything. Vatican theologian Christoph Schoenborn made headlines with a New York Times article a year ago which endorsed the ID theory that has roiled US academic debate and appeared to back full-fledged Creationism, the core Bible story.
Just before a brainstorming session with the pope on the eve of his Germany trip, Schoenborn admitted his NYT article had been a little too "cut-and-dried," laying it open to misinterpretation.
Supporters of ID pounced on the NYT article in their fight to win credibility for a theory many scientists see as Creationism in respectable clothing.
In response, the director of the Vatican's Space Observatory, Father George Coyne, said critics of evolutionary theory underestimated God's willingness to give "freedom" to Nature. The Baltimore-born Jesuit, 73, who has just stepped down after 28 years at the helm of the Vatican's flagship science programme, rapped Schoenborn for "underestimating" the US context in which he was speaking and branded Creationism as "a religious movement devoid of all scientific basis".
Schoenborn responded by clarifying his position, saying that evolution as a body of scientific fact was compatible with Catholicism, but that evolution as an ideological dogma that denied design and purpose in Nature was not. But he stressed that more attention should be given to the holes in Darwin's theory, "which (Darwin) himself recognised and regretted".
"The open questions of the theory of evolution should be exposed" rather than pushing Darwinism as the explanation for how life developed, the cardinal said, questioning the propriety of clerics defending evolution. Some reports have claimed Coyne was, in fact, sacked because of his defence of evolution but Vatican sources insist he asked to quit because of ill health.
Benedict - who taught Schoenborn at Regensburg before becoming the Vatican's dogma pointman, his previous job - was last heard on the subject on World Youth Day in April. He told his young audience in St Peter's that "science supports a reliable, intelligent structure of matter, the design of Creation".
On Tuesday he echoed this view, saying that "Creational Reason, the Spirit that operates everything...fosters development".
"Accounts about Man don't add up without God, just as accounts about the world, the vast universe, do not add up without Him".
Evolutionary theories, he said, posit that "the Irrational, without reason, strangely produces a cosmos controlled by mathematical rules, and even man and his (powers of) reason".
In December, in a controversial ruling, a US local court rejected the teaching of ID alongside the theory of evolution.
Several US states teach the theory, claiming it is as credible as Darwinism. Critics say ID is merely camouflaged Creationism and does not belong in science curricula. Supporters of ID hold that some features of the universe and living things are so complex they must have been designed by a higher intelligence.
