new. the important question is, ‘What is the function of
consciousness?’, or ‘What does consciousness do?’3 Consciousness has no independent
function
Zombies are not possible because any animal that could
do everything we do would necessarily be conscious.
Consciousness is not separable from evolved adaptive
traits such as intelligence, language, memory, and prob-
lem-solving. the important question is, ‘Why does con-
sciousness necessarily come about in creatures that have
evolved abilities like ours?’
(note that functionalism falls into this category, but the
term can seem confusing in this context. Functionalism
claims that mental states are functional states, so explain-
ing the functions performed also explains consciousness.)4 Consciousness is illusory
our ideas about consciousness are so confused that we fall
for the zombic hunch, invent the hard problem, and worry
about why consciousness evolved. the relevant question
is, ‘Why are creatures with abilities like ours so deluded
about their own consciousness?’evolve out of unconscious matter? William James, a pio-
neer of evolutionary psychology, explained the central
problem.
The point which as evolutionists we are bound to
hold fast to is that all the new forms of being that
make their appearance are really nothing more
than results of the redistribution of the original and
unchanging materials. The self-same atoms which, chaotically dispersed,
made the nebula, now, jammed and temporarily caught in peculiar
positions, form our brains; and the ‘evolution’ of the brains, if understood,
would be simply the account of how the atoms came to be so caught and
jammed. [. . .] But with the dawn of consciousness an entirely new nature
seems to slip in.
(1890, i, p. 146)James set himself the task of trying to understand
how consciousness could ‘slip in’ without recourse
to a mind-stuff, mind-dust, or soul. This is essentially
the task we face today, but we should not confuse it
with two other related questions. The first concerns
when consciousness arises during human develop-
ment. For example, is an unfertilised egg or a human
foetus conscious? And if not, when does a baby or
a child become conscious? The second (Chapter 10)
concerns which creatures alive today are conscious.
Answers to these may, or may not, help us with the
question at issue here: when did consciousness first
evolve?
Over this question there is strong disagreement.
Some believe that its appearance was gradual, such
as Susan Greenfield, who claims that ‘consciousness
is not all-or-none but comes in degrees’, increas-
ing like a dimmer switch with increasing brain size
(Greenfield, 2000, p. 176). Others think quite the
reverse. ‘One thing of which we can be sure is that
wherever and whenever in the animal kingdom con-
sciousness has in fact emerged, it will not have been
a gradual process’ (Humphrey, 2002, p. 195).Some place its arrival very early. For example,
panpsychists believe that everything is conscious,
although the consciousness of stones and streams
is much simpler than that of slugs and sea lions. On
this view, consciousness itself came long before
biological evolution began, but the kind and com-
plexity of consciousness might still have evolved.
Some believe that life and consciousness are insep-
arable, so that as soon as living things appeared on
earth, approximately four billion years ago, there‘with the dawn of
consciousness an
entirely new nature
seems to slip in’(James, 1890, i, p. 146)
‘consciousness is not
all-or-none but comes in
degrees’(Greenfield, 2000, p. 176)‘it will not have been a
gradual process’(Humphrey, 2002, p. 195)would have been consciousness. Some people
equate consciousness with sensation, in which
case it would have appeared with the first sense
organs. The problems here concern defining sen-
sation. For example, does the sunflower’s ability to
turn towards a source of light count as sensation
and hence consciousness? Is the bacterium follow-
ing a chemical gradient aware of the concentration
it responds to?
Others think that consciousness requires a nervous
system of some particular level of complexity or that
it needs a brain, in which case consciousness would
have appeared when these structures evolved.
Defending ‘the ancient origins of consciousness’,
Todd Feinberg and Jon Mallatt (2016) lay out what
they call ‘the defining features of consciousness’
(p. 18). Being alive is not sufficient, nor is having a
simple nervous system with reflexes. More complex
neural hierarchies are needed that can create iso-
morphic representations – that is, representations
which map features directly from the outside world
onto the sensory system. This, they suggest, hap-
pened sometime between 560 and 520 million years
ago, during the time of the Cambrian explosion, per-
haps with a creature like amphioxus, a simple fish-
like marine animal. ‘The isomorphic visual images
were processed by the expanding brain into mental
images, which we propose marks the arrival of con-
sciousness’ (2016, p. 92). They can propose these
‘defining features’ as the criteria for consciousness
(Chapter 10), but it is hard to see how their proposal could be tested, and others
make equally specific and very different claims about the arrival of conscious-
ness. Humphrey places it at 300 million years ago, and Bernard Baars (2012) ties it
to the emergence of the mammalian brain around 200 million years ago.
Finally, there are those who believe that consciousness is a much more recent
phenomenon, dating from the appearance of specialised social skills in our recent
ancestors. Those skills include social perception, imitation, deception, theory of
mind, and language.The most recent origin for consciousness was suggested by American psychol-
ogist Julian Jaynes in his controversial book The Origin of Consciousness in the
Breakdown of the Bicameral Mind (1976). Going back three thousand years to
the earliest written records, he searched for clues to the presence or absence
of a subjective conscious mind. The first text that allowed him accurate
enough translation was the Iliad, an epic story of revenge, blood, and tears
which describes events that probably occurred around 1230 BC and were writ-
ten down around 900 or 850 BC. ‘What is mind in the Iliad?’ asks Jaynes. ‘The
answer is disturbingly interesting. There is in general no consciousness in the
Iliad’ (p. 69).