Chapter
Eleven
The function of consciousness
you can remove health while leaving all the bodily powers and functions intact. In
the case of health the fallacy is obvious, yet people keep making the mistake with
consciousness. They imagine that it is possible to remove consciousness while
leaving all the cognitive systems intact. ‘Health isn’t that sort of thing, and neither
is consciousness’ (p. 325).
Douglas Hofstadter (2007) imagines a very fancy car that might, or might not,
come with a chrome ornament in the shape of a Flash Gordon rocketship. But
consciousness is not an orderable ‘extra feature’ like this. You cannot order a car
with a tiny engine and then say to the dealer, ‘Also, please throw in Racecar Power
for me’ (or rather, you can order it, but it won’t arrive). Nor does it make sense to
order a car with a huge engine and then ask how much more you have to pay to
get Racecar Power as well.
For Hofstadter, consciousness is like the power of a well-built car: it comes with
good design. For Dennett, when you have given an evolutionary account of the
talents of zimboes in monitoring their own (unconscious) informational states,
you have done the job. There is not in addition something called consciousness
that has effects in its own right. On this version of functionalism (Chapter 8) or on
any version of illusionism (Chapter 3), any creatures that could carry out all the
functions we do would necessarily be conscious like us.
We can now see that Humphrey was wrong. It is not true that ‘Either we throw
away the idea that consciousness evolved by natural selection, or else we have
to find a function for it’. The alternative is to accept that consciousness is more
like health or horsepower than an optional awareness module. If we do that, the
mystery changes and so does the task of understanding the evolution of con-
sciousness. The mystery becomes why consciousness seems to be a high-spec
upgrade when it is not. The task is not only to explain how evolution produced
humans with all their particular skills and abilities, but also why creatures with
those skills and abilities are conscious, or are under the illusion that they are con-
scious, like us.
With this in mind, we can now see that there are four ways of approaching the
evolution of consciousness (see Concept 11.1). If you believe in physically and
behaviourally indistinguishable zombies, then it is forever a mystery why con-
sciousness evolved, and you might as well give up. If you reject the possibility
of zombies, you have three choices. Consciousness must be something sepa-
rable from all the other skills and abilities we have evolved, in which case the
task is to explain the function of consciousness, and how and why it evolved
in its own right. Alternatively, consciousness necessarily comes about when
those skills and abilities evolve, and the task is to explain why. Finally, maybe
we are deluded about the nature of consciousness and are trying to explain
the wrong thing entirely. Then, we have to ask why we evolved to be so easily
deluded.
WHEN CONSCIOUSNESS EVOLVED
Asking why consciousness evolved also means asking when. It seems reasonable
to suppose that a few billion years ago there was no consciousness on this planet
and now there is, but how could consciousness (or awareness or subjectivity)
‘what is health for? Such
a mystery!’(Dennett, 1995c, p. 325)