Based on results from the live audience as well as an online poll, the atheists won the debate. Fifty percent of the in-person audience agreed that science refutes God, up from 37 percent before the debate. The opposing side, arguing against the motion, only gained four percent of the vote after the debate (from 34 percent to 38 percent).
"We have evidence, reason, logic, rationality and empirical methods on our side whereas our opponents have vague hopes and fears," said Krauss, an atheist, during the Intelligence Squared debate. "I've learned to force my beliefs to conform to the evidence of reality. That's where science differs from religion.
"What's better about science is ... our faith is shakable," he added, noting that he would throw out a belief if new evidence contradicts it.
What science has taught, the best-selling author (A Universe From Nothing: Why There Is Something Rather Than Nothing) argued, is that God is not necessary to create a universe.
"It looked like everything was designed for the environment which it lived but what Darwin showed us was that a simple proposition, namely that there's genetic variation among a population combined with natural selection, meant that you didn't need supernatural shenanigans, that in fact all the diversity of life on earth could arise from a single life form by natural law," Krauss asserted.
Michael Shermer, an evangelical turned atheist and founding publisher of Skeptic magazine, accused many believers of "confirmation bias," where one arrives at their beliefs for nonrational reasons and then goes back into it after the fact with rational reasons to justify it.
For the Christian panelists, however, science has only pointed more to God and does not conflict with their beliefs.
"We are living at a time when religious believers do not need to be afraid of science. They should, as I do, embrace science and welcome science because correctly understood, far from pointing away from God, science thrillingly points to God," D'Souza, author of What's So Great About Christianity and former president of The King's College, contended.
Addressing the Big Bang theory, D'Souza agreed with Krauss that there was nothing in the beginning – no energy, no particles, no time or space. And that is "completely consistent with what Christians believe and exactly said by the ancient Hebrews thousands of years ago without doing a single experiment but solely on the basis of 'God told us.'"
"And the astounding fact is that 2,000 years later, modern science after climbing round and round the mountain has arrived at the top only to find a bunch of theologians who have been sitting there for centuries," said D'Souza to laughter from the audience.
On evolution, the Christian apologist stated that the theory is not about the origin of life but simply about the transition between life forms.
"The fact is that there have to be certain conditions – self-replicating cells, an old universe, an old earth, that are necessary for evolution to take place. The fine-tuned universe is a precondition of Darwinian evolution itself."
D'Souza and Ian Hutchinson, professor of Nuclear Science and Engineering at MIT and a Christian, were also challenged on the notion of miracles and how they are consistent with science.
Krauss believes miracles require the suspension of the laws of physics. But D'Souza countered, "No. Miracles simply say that the laws of physics are incomplete. The laws of physics are generalizations that reflect the limits of human knowledge. These aren't nature's laws; they're Newton's laws and it took an Einstein to modify them."
Both a good scientist and a Christian?
Can those who believe in God be good scientists?
According to Krauss, there can be functioning scientists who believe in God. But, he added, such scientists tend to leave their beliefs at the door of the lab. He asserted that the minute scientists bring God into the lab, they stop being good scientists.
Hutchinson responded, "What got modern science going in the first place is a belief in the faithfulness of God, of a Creator who made a rational creation. The reason why science as we know it grew up in the West was in part because Christianity in its philosophical and theological viewpoints, including the belief in God, served as a kind of hospitable environment in which that science could grow up."
D'Souza made clear that the Bible is not a science manual and doesn't try to prove God.
But it does make certain claims about the world and about man – it says God made the universe out of nothing but not man out of nothing, he noted. It just doesn't say how. And that's where science comes in. Science attempts to give explanations "that actually don't refute the Bible," he argued.
He noted that only 3 percent of Christians subscribe to a fundamentalist reading of the Bible and that creation science is "nonsense."
"If science refutes God, you'd expect that one person who would know that would be Charles Darwin ... What caused him to lose his own faith had nothing to do with evolution but because he lost one of his daughters ... It was the issue of suffering, not science, that turned Darwin against God."
Intelligence Squared debates are based on the debate program in London by the same name. Intelligence Squared U.S., largely supported by The Rosenkranz Foundation, has presented more than 60 debates on such topics as legalizing drugs, the financial crisis, the Middle East and the death of mainstream media.
On the Web: intelligencesquaredus.org/debates/past-debates