As a debate colleague, Chopra chose Jean Houston, a philosopher and researcher into the nature of consciousness who has studied spiritual practices around the world. She is equally firm in her position. "Does God have a future?" she said. "Yes. I am not sure about human beings having a future, but there is no issue around God."
The debate took place at the California Institute of Technology in Pasadena in front of an audience of almost 1,000. Each side laid out its central points early on.
"Things that God used to explain are now explained through natural forces," Shermer said. "Belief in God and the kind of God you believe in and the sort of religion you adhere to depend very much on where you happen to have been born and in which century you happen to be born. That alone tells us that there's a strong cultural component."
Shermer then went into some of the neuroscience behind belief. "We do tend to look at the world and find meaningful patterns and impose on those patterns intentional agency," he said. "And so, the intentional agents are things like ghosts and Gods and demons and angels and aliens and so forth. And God is another version of that. It's a projection of what our brain is doing to try to understand and make sense of the world."
To Shermer, this is proof that humans created God and not the other way around.
In response, Chopra invoked today's greatest realm of scientific mystery, quantum mechanics, which explores how the tiniest particles that make up all matter behave.
"Today, science tells us that the essential nature of reality is non-local correlation," said Chopra. "Everything is connected to everything else. But there is hidden creativity. There are quantum leaps of creativity. There's something called the observer effect where intention orchestrates space-time events."
Chopra said such scientific discoveries point to an intelligent consciousness at the center of the creation.
"That is the very embodiment of woo-woo," Shermer said, shaking his head. "What he means by non-local is that everything in the universe is interconnected. And it just is not true."
Harris brought things back down to earth. "Ninety percent of the people watching this on television will never have heard of non-locality, and if we could explain it to them they're not going to care about it. They're worried about Jesus. They're worried about the collision with the Muslim world."
It was no surprise that there were some scientists in the audience. One theoretical physicist offered to give Chopra a short course in quantum physics to help him refine his usage of some of the terms. The invitation was accepted. "I would like to be educated so I can be clearer in my dialogue," Chopra said.
The physicist in turn asked to be further educated about Chopra's view of consciousness.
While the debate may have ended on stage, the participants -- and even the theoretical physicist from the audience -- have continued to discuss the issue over e-mail.