organisational network for monitoring body

states, setting priorities and, within the brain

itself, creating the separation between inner

world and outer world. In its functionality, it is

a bit like a utility on your computer, though

one that has evolved to grow and develop.

Complex brains are good at that sort of

thing – creating high-level neural patterns

to make sense of the world. We lack a word

to describe this function, but instances

abound. A simpler example is our normal

three-dimensional visual perception.

Here, a network of neurons in the visual

cortex compares the slightly offset two-

dimensional inputs it gets from each eye.

The comparison is used to create an image of

a three-dimensional world. Thus we literally

see – and not merely infer – real depth.

The brain constructs a range of make-

sense-of-the-world neurotools; one is the

future, one is the past and one is self. Does

that mean my self is not real? On the contrary.

It is every bit as real as the three-dimensional

world we see, or the future we prepare for, or

the past we remember. It is a tool tuned,

in varying degrees, to the reality of brain and

world; like other tools, it can malfunction,

for example, in schizophrenia.

Essentially, it is high-level tools like this

which allow us to do the amazing things we

humans do, including thinking of oneself as a

self. Is one cheapened by this neuroscientific

knowledge? I think not. Self-esteem and

self-worth are wholly compatible with

realising that brains make us what we are.

As for self-esteem, we do know that it is highly

dependent on successful social interactions:

on respect, love, accomplishment, but also on

temperament, hormones and serotonin.

Moreover, the beauty, intricacy and

sophistication of the neurobiological machine

that makes me “me” is vastly more fascinating

and infinitely more awesome than the

philosophical conception of the brain-free

soul that somehow, despite the laws of

physics, exercises its free will in a causal

vacuum. Each of us is a work of art,

sculpted first by evolution, and second by

experience in the world. With experience and

reflection one’s social perception matures,

and so also does the level of autonomy.

Aristotle called it wisdom. ●

Patricia Churchland is the University of California President’s Professor of Philosophy at UC San Diego. Her most recent book is Brain-wise: Studies in neurophilosophy (MIT Press/Bradford Books, 2002)

PAUL

BLO

W

IS ONE CHEAPENED BY THE KNOWLEDGE THAT THE SELF IS A TOOL CREATED BY THE BRAIN TO MAKE SENSE OF THE WORLD? I THINK NOT

J. RICHARD GOTTEstablishing a self-supporting colony on Mars would change world history – it wouldn’t be just “world” history any more. A Mars colony would provide a life insurance policy against whatever catastrophes might occur on Earth. Our planet is littered with the bones of extinct species offering mute testimony that such catastrophes do occur. The real space race is whether we will colonise off Earth onto other worlds before money for the space programme runs out.

History shows that expensive projects such as the Egyptian pyramids or Chinese naval explorations are often abandoned after a while. The human space-fl ight programme is not very old, suggesting we should colonise soon, while we have the chance. Colonies are a great bargain and have the potential to found other colonies: the fi rst words spoken on the moon were in English not because the UK sent astronauts to the moon but because England planted a colony in North America. Launching as many tonnes into low-Earth orbit in the next 50 years as we have in the last 50 could provide a suffi cient basis for establishing a self-supporting Mars colony. This is not a prediction but a hope. Will we be smart enough to do this?

J. Richard Gott is professor of astrophysics at Princeton University

MICHAELGAZZANIGAThe next 50 years will focus on the social mind, the fact that humans are social animals and that most of the time our personal mental state is to be thinking about relationships. Does our species have a moral compass? Do we mostly get along because we enjoy common reactions to similar challenges? Can we truly understand how we understand others, their intentions, desires and beliefs? Understanding these issues is what is coming down the pike.

Michael Gazzaniga is director of the Sage Center for the Study of the Mind at the University of California

www.newscientist.com 18 November 2006 | NewScientist | 45

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