K. Eric Drexler's Engines of Creation is an enormously
original book about the consequences of new technologies.
It is ambitious and imaginative and, best of all, the
thinking is technically sound.
But how can anyone predict where science and technology
will take us? Although many scientists and technologists
have tried to do this, isn't it curious that the most
successful attempts were those of science fiction writers
like Jules Verne and H. G. Wells, Frederik Pohl, Robert
Heinlein, Isaac Asimov, and Arthur C. Clarke? Granted,
some of those writers knew a great deal about the science
of their times. But perhaps the strongest source of their
success was that they were equally concerned with the
pressures and choices they imagined emerging from their
societies. For, as Clarke himself has emphasized, it is
virtually impossible to predict the details of future
technologies for more than perhaps half a century ahead.
For one thing, it is virtually impossible to predict in
detail which alternatives will become technically
feasible over any longer interval of time. Why? Simply
because if one could see ahead that clearly, one could
probably accomplish those things in much less time -
given the will to do so. A second problem is that it is
equally hard to guess the character of the social changes
likely to intervene. Given such uncertainty, looking
ahead is like building a very tall and slender tower of
reasoning. And we all know that such constructions are
untrustworthy.
How could one build a sounder case? First, the
foundations must be very firm - and Drexler has built on
the soundest areas of present-day technical knowledge.
Next, one must support each important conclusion step in
several different ways, before one starts the next. This
is because no single reason can be robust enough to stand
before so many unknowns. Accordingly, Drexler gives us
multiple supports for each important argument. Finally,
it is never entirely safe to trust one's own judgments in
such matters, since all of us have wishes and fears which
bias how we think - without our knowing it. But, unlike
most iconoclasts, Drexler has for many years courageously
and openly exposed these ideas to both the most
conservative skeptics and the most wishful-thinking
dreamers among serious scientific communities like the
one around MIT. He has always listened carefully to what
the others said, and sometimes changed his views
accordingly.
Engines of Creation begins with the insight that what we
can do depends on what we can build. This leads to a
careful analysis of possible ways to stack atoms. Then
Drexler asks, "What could we build with those atomstacking
mechanisms?" For one thing, we could manufacture
assembly machines much smaller even than living cells,
and make materials stronger and lighter than any
available today. Hence, better spacecraft. Hence, tiny
devices that can travel along capillaries to enter and
repair living cells. Hence, the ability to heal disease,
reverse the ravages of age, or make our bodies speedier
or stronger than before. And we could make machines down
to the size of viruses, machines that would work at
speeds which none of us can yet appreciate. And then,
once we learned how to do it, we would have the option of
assembling these myriads of tiny parts into intelligent
machines, perhaps based on the use of trillions of
nanoscopic parallel-processing devices which make
descriptions, compare them to recorded patterns, and then
exploit the memories of all their previous experiments.
Thus those new technologies could change not merely the
materials and means we use to shape our physical
environment, but also the activities we would then be
able to pursue inside whichever kind of world we make.
Now, if we return to Arthur C. Clarke's problem of
predicting more than fifty years ahead, we see that the
topics Drexler treats make this seem almost moot. For
once that atom-stacking process starts, then "only fifty
years" could bring more change than all that had come
about since near-medieval times. For, it seems to me, in
spite of all we hear about modern technological
revolutions, they really haven't made such large
differences in our lives over the past half century. Did
television really change our world? Surely less than
radio did, and even less than the telephone did. What
about airplanes? They merely reduced travel times from
days to hours - whereas the railroad and automobile had
already made a larger change by shortening those travel
times from weeks to days! But Engines of Creation sets us
on the threshold of genuinely significant changes;
nanotechnology could have more effect on our material
existence than those last two great inventions in that
domain - the replacement of sticks and stones by metals
and cements and the harnessing of electricity. Similarly,
we can compare the possible effects of artificial
intelligence on how we think - and on how we might come
to think about ourselves - with only two earlier
inventions: those of language and of writing.
We'll soon have to face some of these prospects and
options. How should we proceed to deal with them? Engines
of Creation explains how these new alternatives could be
directed toward many of our most vital human concerns:
toward wealth or poverty, health or sickness, peace or
war. And Drexler offers no mere neutral catalog of
possibilities, but a multitude of ideas and proposals for
how one might start to evaluate them. Engines of Creation
is the best attempt so far to prepare us to think of what
we might become, should we persist in making new
technologies.

MARVIN MINSKY
Donner Professor of Science
Massachusetts Institute of Technology