Finding the Neural Correlates of Consciousness Is Still a Good Bet

In 1870, Alfred Russell Wallace wagered £500—a huge sum in those days—that he could prove the flat-Earther John Hampden wrong. Wallace duly did so, but the aggrieved Hampden never paid up.

Since then, a lively history of scientific wagers has ensued—many of them instigated by Stephen Hawking. Just last month in New York, the most famous recent wager was settled: a 25-year-old bet over one of the last great mysteries in science and philosophy. The bettors were neuroscientist Christof Koch and philosopher David Chalmers, both known for their pioneering work on the nature of consciousness. Chalmers won. Koch paid up.

Back in the late 1990s, consciousness science was full of renewed promise. Koch—a natural optimist—believed that 25 years was more than enough time for scientists to uncoverthe pair staked a on the outcome.