- Deutsch, David.
The Beginning of Infinity.
New York: Viking, 2011.
ISBN 978-0-670-02275-5.
-
Were it possible to communicate with the shades of departed
geniuses, I suspect
Richard Feynman
would be dismayed at the
prospect of a distinguished theoretical physicist committing
phil-oss-o-phy in public, while
Karl Popper
would be pumping his fist in exultation and shouting “Yes!”.
This is a challenging book and, at almost 500 pages in the print
edition, a rather long one, but it is a masterpiece well worthy of
the investment in reading it, and then, after an interval to let its
implications sink in, reading it again because there is so much
here that you're unlikely to appreciate it all in a single reading.
The author attempts nothing less ambitious than a general theory
of the creation of knowledge and its implications for the future
of the universe. (In what follows, I shall take a different approach
than the author in explaining the argument, but I think we arrive
at the same place.) In all human endeavours: science, art, morals,
politics and governance, technology, economics, etc., what we ultimately
seek are good explanations—models which allow us to
explain a complex objective reality and make predictions about its
behaviour. The author rejects the arguments of the relativists and
social constructionists that no such objective reality exists, as well as
those of empiricists and advocates of inductive reasoning that our
models come purely from observation of events. Instead, he contends
that explanations come from conjectures which originate in the
human mind (often sparked by experience), which are then
tested against objective reality and alternative conjectures,
in a process which (in the absence of constraints which obstruct the
process, such as reliance on received wisdom instead of free inquiry)
inevitably converges upon explanations which are minimal and
robust in the sense that almost any small change destroys their
predictive power.
For example, if I were so inclined, I could invent a myth involving
gods and goddesses and their conflicting wills and goals which would
exactly replicate the results of Newton's laws of mechanics. But
this would be a bad explanation because the next person could come up
with their own myth involving an entirely different pantheon which
produced the same results. All of the excess baggage contributes
nothing to the explanation, while there's no way you can simplify
“F=ma” without breaking the entire
structure.
And yet all of our explanations, however elegant and well-tested, are
simply the best explanations we've found so far, and likely to be
incomplete when we try to apply them to circumstances outside the
experiences which motivated us to develop them. Newton's laws fail
to describe the motion of objects at a substantial fraction
of the speed of light, and it's evident from fundamental conflicts in
their theoretical structure that our present theories of the very
small (quantum mechanics) and the very large (general relativity) are
inadequate to describe circumstances which obtained in the early
universe and in gravitational collapse of massive objects.
What is going on here, contends Deutsch, is nothing other than
evolution, with the creation of conjectures within the
human mind serving as variation and criticism of them based on
confrontation with reality performing selection. Just as biological
evolution managed over four billion years or so to transform the
ancestral cell into human brains capable of comprehending structures
from subatomic particles to cosmology, the spark which was ignited
in the brains of our ancestors is able, in principle, to explain
everything, either by persistence in the process of
conjecture and criticism (variation and selection), or by building
the tools (scientific instruments, computers, and eventually perhaps
our own intellectually transcendent descendents) necessary to
do so. The emergence of the human brain was a phase transition
in the history of the Earth and, perhaps, the universe. Humans
are universal explainers.
Let's consider the concept of universality. While
precisely defined in computing,
it occurs in many guises. For example, a phonetic alphabet (as
opposed to a pictographic writing system) is capable of encoding all possible
words made up of the repertoire of sounds it expresses, including those
uninvented and never yet spoken. A positional number system can encode
all possible numbers without the need to introduce new symbols for
numbers larger or smaller than those encountered so far. The genetic
code, discovered as best we can determine through a process of chemical
evolution on the early Earth, is universal: the same code, with a different
string of nucleotides, can encode both brewer's yeast and Beethoven. Less
than five million years ago the human lineage diverged from the common
ancestor of present-day humans and chimpanzees, and between that
time and today the human mind made the “leap to universality”,
with the capacity to generate explanations, test them against reality,
transmit them to other humans as
memes,
and store them extrasomatically as oral legends and, eventually,
written records.
Universality changes all the rules and potential outcomes. It is a
singularity in the mathematical sense that one cannot predict the
future subsequent to its emergence from events preceding it. For
example, an extraterrestrial chemist monitoring Earth prior to the
emergence of the first replicator could have made excellent
predictions about the chemical composition of the oceans and its
interaction with the energy and material flows in the environment, but
at the moment that first replicating cell appeared, the potential for
things the meticulous chemist wouldn't remotely imagine came into
existence: stromatolites, an oxygen-rich atmosphere, metazoans,
flowers, beetles, dinosaurs, boot prints on the Moon, and the
designated hitter rule. So it is with the phase transition to
universality of the human mind. It is now impossible to predict based
on any model not taking that singularity into account the fate of the
Earth, the Sun, the solar system, or the galaxy. Barring societal
collapse, it appears probable that within this century individual
wealthy humans (and a few years thereafter, everybody) will have the
ability to launch
self-replicating
von Neumann probes into the galaxy with the potential of remaking it
in their own image in an eyeblink compared to the age of the universe
(unless they encounter probes launched by another planet full of
ambitious universal explainers, which makes for another whole set of
plot lines).
But universality and evolutionary epistemology have implications much closer
to home and the present. Ever since the Enlightenment, Western culture has
developed and refined the scientific method, the best embodiment of the
paradigm of conjecture and criticism in the human experience. And yet,
at the same time, the institutions of governance of our societies have been
largely variations on the theme of “who shall rule?”, and the
moral underpinnings of our societies have either been based upon received
wisdom from sacred texts, tradition, or the abdication of judgement inherent
in multicultural relativism. The author argues that in all of these
“non-scientific” domains objective truth exists just as it
does in mechanics and chemistry, and that we can discover it and ever
improve our explanations of it by precisely the same process we use
in science: conjecture and criticism. Perversely, many of the institutions
we've created impede this process. Consider how various political systems
value compromise. But if there is a right answer and a wrong answer,
you don't get a better explanation by splitting the difference. It's
as if, faced with a controversy between geocentric and heliocentric models
of the solar system, you came up with a “compromise” that
embodied the “best of both”. In fact,
Tycho did precisely that,
and it worked even worse than the alternatives. The value of democracy is
not that it generates good policies—manifestly it doesn't—but
rather that it provides the mechanism for getting rid of bad policies and
those who advocate them and eventually selecting the least bad policies
based upon present knowledge, always subject to revision based on what
we'll discover tomorrow.
The Enlightenment may also be thought of as a singularity. While there
have been brief episodes in human history where our powers as
universal explainers have been unleashed (Athens and Florence come
to mind, although there have doubtless been a multitude of others
throughout history which have left us no
record—it is tragic to think of how many Galileos
were born and died in static tribal societies), our
post-Enlightenment world is the only instance
which has lasted for centuries and encompassed a large part of
the globe. The normal state of human civilisation seems to be a
static or closed society dominated by tradition and taboos which
extinguish the inborn spark of universal explanation which triggers
the runaway exponential growth of knowledge and power. The dynamic
(or open) society (1, 2) is a
precious thing which has brought unprecedented prosperity to the
globe and stands on the threshold of remaking the universe
as we wish it to be.
If this spark be not snuffed by ignorance, nihilism, adherence to
tradition and authority, and longing for the closure of some final
utopia, however confining, but instead lights the way to a boundless
frontier of uncertainty and new problems to comprehend and solve, then
David Deutsch will be celebrated as one of the visionaries who pointed
the way to this optimistic destiny of our species and its inheritors.
September 2011 