.- At the March 24 “Reason Rally” in Washington, D.C., an estimated 20,000 atheists and agnostics heard author and activist Richard Dawkins encourage mockery of Catholic beliefs and those of other religions.

“Don't fall for the convention that we're all 'too polite' to talk about religion,” Dawkins said, before urging rally attendees to ridicule Catholics' faith in the Eucharist.

“Religion makes specific claims about the universe which need to be substantiated, and need to be challenged – and if necessary, need to be ridiculed with contempt,” he told the cheering crowd on the National Mall.

“For example, if they say they're Catholic: Do you really believe, that when a priest blesses a wafer, it turns into the body of Christ? Are you seriously telling me you believe that? Are you seriously saying that wine turns into blood?”

If the answer is yes, Dawkins suggested atheists should show contempt for believers instead of ignoring the issue or feigning respect.

“Mock them,” he told the crowd. “Ridicule them! In public!”

The former Oxford professor and author of “The God Delusion” was among the headliners of Saturday's rally, which also featured comedian Eddie Izzard, punk rock group Bad Religion, and magician James Randi.

Dawkins called for atheists to identify themselves in public, for the sake of a more openly secular society.

He also claimed that many self-identified Christians are only nominal adherents of their religion, and should be given a chance to disavow beliefs that they may not hold.

“When you meet somebody who claims to be religious, ask them what they really believe,” Dawkins suggested.

“If you meet somebody who says he's Catholic, for example, say: 'What do you mean? Do you just mean you were baptized Catholic, because I'm not impressed by that.'”

But those who hold to the doctrines of their faith should be openly ridiculed, Dawkins said.

“I don't despise religious people; I despise what they stand for,” he explained.

Elsewhere in his remarks, the former professor praised the “truth” and “beauty” of Darwinian evolution, and the ability of the “incredible process” to produce life with the “illusion of design.”

“How is it conceivable,” he wondered, “that the laws of physics should conspire together – without guidance, without direction, without any intelligence – to bring us into the world?”

It was “almost too good to be true,” he rhapsodized, that this “mechanical, automatic, unplanned, unconscious process” should produce human intelligence.

“That's not just true, it's beautiful,” he declared to cheers from the crowd of agnostics and atheists.

“It's beautiful because it's true,” said Dawkins. “And it's almost too good to be true.”