Is there a limit to what we
can know? This is one of the great questions that have occupied the creative
minds of some of the world’s most illustrious luminaries. All of them have been
stumped and no definitive answer has been provided. The advance of science (or
perhaps more specifically, the advance of technology) is changing the
epistemological landscape and the old unanswerable questions about limits to
human understanding are being brought to sharp focus.
Enter Marcelo Gleiser and his
latest work The Island of Knowledge. The
book is a broad treatment of the topic. Gleiser begins at the beginning with a discussion
of the earliest philosophers of ancient Greece and highlights their ruminations
on the nature of the world and the limits of what we can know about it. The
narrative speeds along through history to the quantum age. This isn’t a history
book. You won’t find here an exhaustive account of all the philosophers and
scientists who have produced some answer to the mystery of knowledge
limitations. He spends some time on the history of science and epistemology to
ground the book and to show the perennial befuddlement of all attempts to
grapple with the topic. Most of the book is spent discussing modern science and
the breathtaking weirdness of what physicists and astronomers have uncovered. It
is here, in our day, where we see most clearly the answer to the above
question. Everywhere you turn, in every intellectual discipline of science, the
same answer resounds: Yes, there are limits to what we can know about the world
and ourselves.
Gleiser enumerates the
findings of various disciplines, particularly physics, astronomy and mathematics,
highlighting technological limitations to our ability to observe the universe
both at the macro (big bang and expanding universe) and at the micro levels
(the quantum world). The implications of
quantum physics are especially disconcerting to individuals who want the
certainty that comes with absolute knowledge. Gleiser spends most of his
analytical-descriptive work on the quantum age.
There will be some readers who
will say, when they are told there is a limit to what we can know, “Well duh!”
But for many scientists whose lives are informed by an ethic of the search for
ultimate answers, a search that will eventually be rewarded, this conclusion
will come as a shock—kind of like cold water splashed on the brain. We exist on
an island. This fact must be faced boldly and digested for all the import it
will have on what one might call the “meaning of intellectual life.”
The final chapter acts as an
epitaph to the absolutist’s dream. I will quote one passage at some length as a
finale to this review.
It is too simplistic a hope to
aspire to complete knowledge. Science needs to fail in order to move forward.
We may crave certainty but must embrace uncertainty in order to grow. We are
surrounded by horizons, by incompleteness. All we see are shadows on cave
walls. Yet it is also too simplistic to consider such limits as insurmountable
obstacles. Limits are triggers: they teach us something about ourselves while taunting
us to keep edging forward, in search of answers. We push the limits and keep on
pushing so that we can better know who we are. The same ongoing growth process
that we see in science—forward, backward, but always charging ahead—we should
see in each of us, in our individual pursuits. The day we become too afraid to
step into the unknown is the day we stop growing. (p.280).
It is a grand statement and adds a bit of poetic
musing to the final chapter of the book. Allow me two observations. First
notice the allusion to Plato and “shadows on cave walls.” Plato, a very keen
observer of human nature, prodded his fellow Athenians to reach for the
permanent unchanging Forms as the only true hope for knowledge. This world view
is passé these days—that there may be some eternal, unchanging realm beyond the
mundane—but wouldn’t it be nice. Secondly, it may be the way I read the book
and this passage in particular, but I can’t help but think that Gleiser
bristles and chomps at the bit as one who cannot quite commit to his own
conclusions. The limits to knowledge are chaffing. He vacillates, at one moment
saying we are surrounded by incompleteness and at the next suggests it is too
simplistic to think these limits insurmountable obstacles. Here then is the human condition, we live on
an island of knowledge looking out to horizons we just can’t reach. Odd. Frustrating. And yet the mystery (it seems to me a
mystery) enchants the world.