Descartes' Error and the Future of Human Life
Essay by Antonio R. Damasio
From Scientific American, October 1994
1.
A
t the beginning of the 1950s, in an
impassioned speech inspired by the threat
of nuclear destruction, William Faulkner
warned his fellow writers that they had
forgotten the problems of the human heart in
conflict with itself." He asked them to leave
no room in their workshops "for anything but
the old verities and truths of the heart, the
old universal truths lacking which any story
is ephemeral and doomed—love and honor
and pity and pride and compassion and
sacrifice."
2. Although the towering nuclear threat
of four decades ago has assumed a less
dramatic posture, it is apparent to all but the
most absent-minded optimists that other
clear and present dangers confront us. The
world population is still exploding; air, water
and food are still being polluted; ethical and
educational standards are still declining;
violence and drug addiction are still rising.
Many specific causes are at work behind all
these developments, but through all of them
runs the irrationality of human behavior,
spreading like an epidemic, and not less
threatening to our future than was the
prospect of nuclear holocaust when
Faulkner was moved to speak.
3. I have always taken his words to
mean that the rationality required for
humans to prevail and endure should be
informed by the emotion and feeling that
stem from the core of every one of us. This
view strikes a sympathetic chord, because
my research has persuaded me that
emotion is integral to the process of
reasoning. I even suspect that humanity is
not suffering from a defect in logical
competence but rather from a defect in the
emotions that inform the deployment of
logic.
4. What evidence can I produce to back
these seemingly counterintuitive
statements? The evidence comes from the
study of previously rational individuals who,
as a result of neurological damage in
specific brain systems, lose their ability to
make rational decisions along with their
ability to process emotion normally. Their
instruments of rationality can still be
recruited; the knowledge of the world in
which they must operate remains available;
and their ability to tackle the logic of a
problem remains intact. Yet many of their
personal and social decisions are irrational,
more often than not disadvantageous to the
individual and to others. I have suggested
that the delicate mechanism of reasoning is
no longer affected by the weights that
should have been imparted by emotion.
5. The patients so affected usually have
damage to selected areas of the frontal,
temporal and right parietal religions, but
there are other conditions for which a
neurological cause has not yet been
identified, whose characteristics are similar
in many respects. The sociopaths about
who we hear in the daily news are intelligent
and logically competent individuals who
nonetheless are deprived of normal
emotional processing. Their irrational
behavior is destructive to self and society.
6. Thus, absence of emotion appears to
be at least as pernicious for rationality as
excessive emotion. It certainly does not
seem true that reason stands to gain from
operating without the leverage of emotion.
On the contrary, emotion probably assists
