- seCtIon one: tHe PRoBLem
The twentieth century saw two notable attempts to make dualism work. In the
1970s, the philosopher of science Karl Popper and neurophysiologist John Eccles
(1977) proposed a theory of dualist interactionism. They argued that the critical
processes in the synapses of the brain are so finely poised that they can be influ-
enced by a non-physical thinking and feeling self. Thus the self really does control
its brain (Eccles, 1994). How it does so, they admit, remains mysterious. The phys-
iologist Benjamin Libet (2004) proposed that a non-physical ‘conscious mental
field’ is responsible for the unity and continuity of subjective experience and for
free will. Somewhat like a physical force field, it emerges from brain activity, but it
can then communicate within the cerebral cortex without using the neural con-
nections and pathways. But how it does this he does not explain.
More recently, the Australian philosopher David Chalmers has proposed a ‘natu-
ralistic dualism’, which he calls ‘an innocent form of dualism, entirely compatible
with the scientific view of the world’ (2007, p. 360). Rather than contradicting
physical principles, it suggests that new ‘bridging principles’, in the form of psy-
chophysical laws, are needed to explain how experience arises from physical pro-
cesses even though the physical world is causally closed. The theory is a version
of property dualism or dual aspect theory, with the central concept of informa-
tion taking both phenomenal and physical forms. As in other versions of dualism,
however, the bridge arguably does not reach the whole way across the gap.
Because hardly anyone admits to being a dualist any more, but dualism is so
hard to get away from, the philosopher Daniel Dennett (1991) coined the term
‘Cartesian materialism’ to describe the position of pretending to be a materialist
but relying on dualist concepts – particularly the idea that there is an identifiable
time and place where everything comes together in the brain and ‘consciousness
happens’. Dennett’s PhD was supervised by Ryle, and he shares Ryle’s view of the
importance of paying careful attention to language use, because the words we
use are part of the way we think. For Dennett, as soon as you say that something
‘enters consciousness’, for example, or ‘reaches the threshold of consciousness’ –
phrases that the neuroscientific literature on consciousness is full of, once you
start to notice them – you are creating a ‘Cartesian Theatre’. You are imagining
that being conscious – enjoying that apparently rich and unified feeling of being
me now – is like being the audience of the show on the stage of a special mental
theatre (a new version of Ryle’s ghost). We will return to this idea in Chapter 5,
but for now the important thing to bear in mind is that theories and statements
about consciousness may be implicitly or explicitly presented as materialist, yet
be something else when you dig a little deeper. Dennett says that ‘accepting
dualism is giving up’ (1991, p. 37). But avoiding it is not easy.
Monist theories try to avoid it, some by claiming that the mental world is funda-
mental, others that the physical world is. So, for example, you might doubt that
real pencils actually exist out there and decide that only ideas or perceptions of
pencils exist – making you a mentalist or an idealist. This does away with the awk-
ward division but makes it very hard to understand why physical objects seem
to have enduring qualities that we can all agree upon – or indeed how science
is possible at all. Even so, there have been many philosophical theories of this
kind. The British empiricist George Berkeley, for example, replaced matter with
sensations in minds.‘[My position] is an
innocent version
of dualism, entirely
compatible with the
scientific view of the
world’
(Chalmers, 2007, p. 360)
‘accepting dualism is
giving up’
(Dennett, 1991, p. 37)
FIGURE 1.3 • Gilbert Ryle (1949) dubbed the
Cartesian view of mind ‘the dogma
of the Ghost in the Machine’.