Review of The Stuff of Thought
- From: Lance <LanceGary@xxxxxxxxx>
- Date: Sat, 03 Nov 2007 13:43:03 -0000
Patricia Churchland
Abstract
Is language the key to thought? Neuroscience suggests it is probably
more complicated than that.
BOOK REVIEWED-The Stuff of Thought: Language as a Window into Human
Nature
by Steven Pinker
Viking: 2007. 512 pp. $29.95
The conventional wisdom in psycholinguistics in the 1980s was that
thought is like external language in all important respects. Each of
us, the argument went, comes genetically equipped with a 'language of
thought' that is reflected in the structure and organization of
speech. Thought is not remotely similar to perception or imagery, or
to the exercise of motor skills. The basic rules governing human
thought and language were believed to be largely unique and
substantially innate, the result of genetic novelty. Understand
language, and - the psycholinguists used to say - you understand
thought.
In this line of reasoning, languages relate to the world as follows:
names denote, as Henry VIII denotes Henry VIII; type terms, such as
planet, refer to the set of all actual planets. Reference, singular or
general, is supposedly fixed when a single person first coins a word -
for example, planet, while pointing to Jupiter. The proper scope of
that term is then said to include all things that 'have the same
nature' as Jupiter, where the relevant sameness relation is said to be
fixed by physical factors (probably unknown). Were it not so, the
story goes, I would not mean what you mean by planet, so communication
would founder. Fortunately, says this argument, the ancient Greeks did
mean exactly what I mean by planet, owing to one having cleverly
dubbed Jupiter a planet. Unfortunately for this theory, the Greeks
also called the Sun, but not the Earth, a planet.
This approach to word meaning is about as applicable to real meaning
as 'Dungeons and Dragons' is to real life. Aptly ridiculed by critics
as 'font-change semantics', the theory still has its disciples.
Including Steven Pinker.
Indeed, it is essentially font-change semantics that Pinker defends
and deploys in his latest engaging doorstop, The Stuff of Thought. He
has revised a few features, but the core ideas - innateness ad
libitum, and the quest for the nature of thought in the analysis of
language - are intact. Like his earlier books The Language Instinct
and The Blank Slate, The Stuff of Thought has very little to do with
the stuff with which we think - namely, neurons.
In leaving neurons out of the story, Pinker is not alone. Jerry Fodor
elevates ignorance of neuroscience to a methodological virtue,
proclaiming, "If you want to understand the mind, study the mind ...
not the brain, and certainly not the genes". His metaphor, embraced by
some psychologists and philosophers, says that the brain is merely the
hardware that happens to implement the cognitive software. Neurons and
their connectivity are as irrelevant to understanding the nature of
mental function as a computer's transistor configurations are to my
using Powerpoint.
Advances in neuroscience and genetics during the past 30 years have
put such thinking on the defensive. For one thing, extravagant claims
about human uniqueness must deal with the discovery that humans have
only about 28,000 genes, and differ from mice in just 300 or so.
Additional constraints emerge with the discovery that human brains are
stunningly similar to other mammalian brains - in components,
connectivity, development, biochemistry and physiology. Topographic
maps in the neocortex, cerebellum, spinal cord and subcortical
structures are standard for representing and computing with neurons.
As such, they suggest constraints relevant to semantics and reasoning.
Maps that represent which parts of the body are receiving what kind of
stimuli are probably crucial to the very nature of our self-
representation and in what we mean by self. The pathways connecting
sensory maps to those representing motor preparation are likely to be
important for reasoning what to do next. Meanings, as W. V. O. Quine
realized some 50 years ago, fundamentally relate to the world not
piecemeal (planet means planet) but through connected representational
networks in the brain that, with varying accuracy, map as a whole on
to reality. These are the maps that get us around the physical and
social worlds.
And getting us around is the basic evolutionary rationale of nervous
systems. Unlike plants that must take what comes, animals are movers.
More sophisticated behaviour emerged with improved capacities to plan,
predict and draw on past experience, which improved chances of
surviving and reproducing.
This observation motivated neuroscientist Rodolfo Llinás, in his 2002
book I of the Vortex, to propose that, at bottom, thinking is the
evolutionary internalization of movement. He meant that thinking is
the generation in the brain of images of a future action, and its
consequences. And generating these images depends on flexibility in
categorizing the current problem as an instance of one kind of event
rather than another, which, in turn, depends on memory for past
experience. Fundamentally, thinking is neural activity in the service
of behaviour (for example, should I flee or fight? Is this attacker
weak or strong?). This almost certainly shapes thinking that seems
detached from motor preparation (such as, where did Earth come from?).
As is so often the case in biology, discovering structure is crucial
in coming to understand function - as in William Harvey's seventeenth-
century revelation that hearts are actually pumps, not biological
cauldrons for concocting animal spirits. To figure out how brains
actually think and what reasoning really amounts to, we need to focus
on understanding their many levels of organization, from neurons to
large-scale systems to behaviour. If thinking is rooted in
internalized movement, it may be more akin to a skill than to a
syllogism. Language may not be the "stuff of thought" after all.
Patricia S. Churchland is professor of philosophy at the University of
California San Diego, La Jolla, California 92093, USA. She is the
author of Brain-Wise: Studies in Neurophilosophy.
Source: Nature
http://www.nature.com/nature/journal/v450/n7166/full/450029a.html
.
- Prev by Date: Re: The neurology of creativity
- Next by Date: Re: The neurology of creativity
- Previous by thread: Re: The neurology of creativity
- Next by thread: A moral identity can lead to extreme choices
- Index(es):
Relevant Pages
|
