Humans are aware of their own and other's thoughts in ways unlike any other animal. But why did consciousness evolve?
Consciousness was for a long time the charged third rail of biology: touch it and … well, maybe you didn’t die, but you were unlikely to get a grant, or tenure. Of course, it helped if you were a Nobel laureate, such as Francis Crick, lauded for his work on DNA, or Gerald Edelman, for his work on antibodies. Yet even their attempts to pin down the electrical-chemical-anatomical (or whatever) substrate of consciousness seemed, until recently, likely to go the way of Albert Einstein’s doomed search for a unified theory of everything. However, the situation has changed dramatically in recent years. Inquiry into the neurobiology of consciousness has become one of the hottest, best-funded, and most media-friendly of research enterprises, along with genomics, stem cells and a few other newly favoured sub-disciplines.For centuries, it was perfectly acceptable for philosophers to ponder consciousness because, after all, no one actually expected them to come up with anything real. Thus, René Descartes’s renowned statement ‘Cogito ergo sum’ (I think therefore I am) becomes, in the words of the early 20th-century American satirist Ambrose Bierce, Cogito cogito ergo cogito sum — I think that I think, therefore I think that I am (which was, according to Bierce, about as close to truth as philosophy was likely to get). Now we have micro-electrodes recording from individual neurons, computer modelling of neural nets, functional MRIs, and an array of even newer 21st-century techniques, all hot on the trail of how consciousness emerges from ‘mere’ matter. Cartesian dualism is on the run, as well it should be.