Thomas Nagel, the American philosopher, wrote: ‘Certain forms of perplexity – for example, about freedom, knowledge, and the meaning of life – seem to me to embody more insight than any of the supposed solutions to those problems’ (Nagel, 1986, p 4). This is equally true of the problem of consciousness. Indeed, the perplexity can be part of the pleasure, as philosopher Colin McGinn points out: ‘ . . . the more we struggle the more tightly we feel trapped in perplexity. I am grateful for all that thrashing and wriggling’ (McGinn, 1999, p xiii).