Dennett believes that there’s every degree of sensitivity and reactivity right down to bacteria. “This idea that there’s this salient marvellous property that you either have or you don’t, that’s the mistake. Bacteria are remarkably adroit, sensitive and self-protective and every cell in our bodies is like a bacterium in this way.” He says that if people knew more about what single celled organisms can do they would realise that they are all conscious.
“What do you think consciousness is? As we build up in complexity from bacteria through to starfish to birds and mammals and us it seems to me the most important threshold is actually us, that we have the bigger and more impressive bag of tricks than any other species. But that doesn’t mean that we have this utterly different phenomenon that happens in our heads and it doesn’t happen in any other heads.”