When the Large Hadron Collider particle accelerator in Geneva began
08
operation in 2008, a fuss was raised by people who had heard that the LHC
09
might create black holes that would ultimately destroy the Earth, ending all
10
life as we know it. Sure, the physicists gave assurances that such an occur-
11
rence was extremely unlikely. But they couldn’t prove that it wasn’t going to
12
happen. And with consequences as drastic as these, can it ever be worth
13
taking the risk, no matter how unlikely the outcome is supposed to be?
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One possible response to such people would be: Consider going home
15
tonight and cooking some pasta for dinner. But before you open the lid on
16
that jar of marinara sauce, ask yourself: What if a freak mutation inside the
17
jar has created a deadly pathogen that will be released if and only if you
18
open the lid, spreading through the world and killing all forms of life?
19
Clearly that would be bad; just as clearly, it seems very unlikely. But you
20
can’t prove that it won’t happen. There’s a chance, even if it’s very small.
21
The resolution is to admit that some credences are so small that they’re
22
not worth taking seriously. It makes sense to act as if we know those pos-
23
sibilities to be false.
24
So we take “I believe x” not to mean “I can prove x is the case,” but rather 25
“I feel it would be counterproductive to spend any substantial amount of
26
time and effort doubting x.” We can accumulate so much evidence in favor
27
of a theory that maintaining skepticism about it goes from being “prudent
28
caution” to being “crackpottery.” We should always be open to changing
29
our beliefs in the face of new evidence, but the evidence required might
30
need to be so overwhelmingly strong that it’s not worth the effort to seek
31
it out.
32
We are left with, not absolute proof of anything, but a high degree of
33
confidence in some things, and greater uncertainty in others. That’s both
34
the best we can hope for and what the world does as a matter of fact grant
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us. Life is short, and certainty never happens.
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02
03
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What Can We Know about the World
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07
without Actually Looking at It?
08
09
10
11
12
13
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15
16
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Our most direct, tangible, verifiable connection to the world around
us is through our senses. We see things, touch them, and come to
understand something about them. But there are times when we
seem to experience reality at a deeper level, without the intermediation of
18
our senses. How are we to account for such experiences as we try to under-
19
stand the big picture?
20
The first time I visited London, wandering around one evening with no
21
real plans, I noticed a poster advertising a concert at St Martin-in- the-
22
Fields, a church near Trafalgar Square. It’s a famous place, especially in
23
classical- music circles, but at that moment its primary virtue was that it was
24
nearby, and a concert seemed to qualify as the kind of cultural enrichment
25
that young people were supposed to seek out when traveling abroad.
26
It was more than that. The concert was by candlelight: electricity extin-
27
guished, the expansive nave was illuminated by the soft flicker of hundreds
28
of small flames. The musicians played selections from Bach and Haydn,
29
sonorous notes reverberating through the shadowy space. Locals and tour-
30
ists alike huddled in overcoats, partaking both of the immediate moment
31
and of the larger sweep of history— musical, architectural, sacred. The
32
vaulted ceilings evoked the night sky, and the cadence of the music played
33
off the human rhythms of breaths and heartbeats. Perhaps for the regular
34
attendees of the concert series it was just another pleasant night out; for me
35S
it was a transcendent experience.
36N
“Transcendent,” from the Latin transcendere, “climb over, surpass,” is a
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word we attach to experiences that seem to reach beyond our mundane
01
physical situation. A wide variety of circumstances can earn the label. For
02
some, transcendence occurs when your spirit comes into direct contact
03
with the divine. For Christians it might involve the witness of the Holy
04
Spirit, while for Hindus or Buddhists it can refer to escaping the material
05
world in favor of a higher spiritual reality. Individuals can experience tran-
06
scendence through prayer, meditation, solitude, or even psychoactive drugs
07
such as ayahuasca or LSD. It could simply be a matter of letting one’s self be
08
lost in a particularly moving piece of music, or in the love of one’s family.
09
Many of us have had such experiences, though disputes arise over whose
10
have been “truly” transcendent. They can play an important role in who we
11
are, helping us achieve peace or joy, even guide us in making important
12
decisions. For our present purposes, we want to know what transcendent
13
experiences imply about the structure of the world. Do they arise from the
14
behavior of the atoms and neurons in our physical brains, or should we
15
think of such moments as indications of contact with a numinous realm,
16
something truly beyond the physical? What, in other words, does transcen-
17
dence teach us about ontology?
18
Behind these questions lurks an even bigger issue. Science advances by
19
observation and experiment: we pose hypotheses about how the world
20
works and then test them by collecting new information and performing
21
the appropriate Bayesian updating. But is that the only way to learn about
22
the world? Isn’t it at least conceivable that we c
ould come to knowledge of
23
reality in ways other than the scientific, using methods other than hypoth-
24
esis testing and collecting data? Certainly, throughout history, people have
25
thought that they’ve gained understanding through revelation, spiritual
26
practice, or other nonempirical methods. The possibility needs to be taken
27
seriously.
28
29
•
30
Science, even broadly construed, is certainly not the only way that we can
31
come to acquire new knowledge. The obvious exceptions are mathematics
32
and logic.
33
While math is lumped together with science in many school curricula—
34
and while they certainly enjoy a close and mutually beneficial relationship—
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at heart they are completely different endeavors. Math is all about proving
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things, but the things that math proves are not true facts about the actual
02
world. They are the implications of various assumptions. A mathematical
03
demonstration shows that given a particular set of assumptions (such as the
04
axioms of Euclidean geometry or of number theory), certain statements
05
inevitably follow (such as the angles inside a triangle adding up to 180 de-
06
grees, or there being no largest prime number). In this sense, logic and
07
mathematics can be thought of as different aspects of the same underlying
08
strategy. In logic, as in math, we start with axioms and derive results that
09
inevitably follow from them. Though we casually speak of “logic” as a single
10
set of results, it is actually a procedure for inferring conclusions from axi-
11
oms. There are different possible sets of axioms from which one can draw
12
logical conclusions, just as there are different sets of axioms one could use
13
in geometry or number theory.
14
The statements we can prove based on explicitly stated axioms are
15
known as theorems. But “theorem” doesn’t imply “something that is true”;
16
it only means “something that definitely follows from the stated axioms.”
17
For the conclusion of the theorem to be “true,” we would also require that
18
the axioms themselves be true. That’s not always the case; Euclidean geom-
19
etry is a marvelous edifice of mathematical results, and certainly useful in
20
many real- world situations, but Einstein helped us see that the actual geom-
21
etry of the world obeys a more general set of axioms, invented by Bernhard
22
Riemann in the nineteenth century.
23
We can think of the difference between math and science in terms of
24
possible worlds. Math is concerned with truths that would hold in any pos-
25
sible world: given these axioms, these theorems will follow. Science is all
26
about discovering the actual world in which we live. Working scientists
27
might find it useful to occasionally consider non- real worlds (like ones with
28
no friction, or a different number of dimensions of space) for purposes of
29
improving their intuition, but among all the possible worlds, it’s the one
30
real world that they ultimately care about. There are possible worlds in
31
which space is flat and Euclid’s axioms are true, and other possible worlds
32
in which space is curved and those axioms are false; but in every possible
33
world, Euclid’s axioms imply that the interior angles of a triangle add up to
34
180 degrees.
35S
The way that science goes about narrowing down our world from an
36N
infinite number of possible ones is pretty clear: by looking at it. Performing
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observations and experiments, gathering data, and using that to increase
01
our credence in the useful, explanatory theories.
02
03
•
04
Science is sometimes described as adhering to methodological naturalism:
05
choosing only to consider explanations that are grounded in the natural
06
world, and to discount from the start possible interventions by non- natural
07
phenomena. This characterization is even used by its supporters, in part for
08
political and strategic reasons. The United States has long been plagued by
09
arguments over the teaching of creationism (biological species were created
10
by God) versus that of Darwin’s theory of natural selection. An approach
11
called Intelligent Design has been put forward as a “scientific” version of
12
creationism, under the theory that it could therefore be taught as science
13
rather than as religion. Opponents of creationism sometimes countered
14
this argument by appealing to the principle of methodological naturalism;
15
by their lights, the reference in Intelligent Design to a supernatural creator
16
immediately rendered it nonscientific. No less an authority than the Na-
17
tional Academy of Sciences wrote,
18
19
Because science is limited to explaining the natural world by
20
means of natural processes, it cannot use supernatural causation
21
in its explanations. Similarly, science is precluded from making
22
statements about supernatural forces because these are outside
23
its provenance.
24
25
Not really. Science should be interested in determining the truth, what-
26
ever that truth may be— natural, supernatural, or otherwise. The stance
27
known as methodological naturalism, while deployed with the best of in-
28
tentions by supporters of science, amounts to assuming part of the answer
29
ahead of time. If finding the truth is our goal, that is just about the biggest
30
mistake we can make.
31
Fortunately, it’s also an inaccurate characterization of what science actu-
32
ally is. Science isn’t characterized by methodological naturalism but by
33
methodological empiricism— the idea that knowledge is derived fro
m our
34
experience of the world, rather than by thought alone. Science is a tech-
S35
nique, not a set of conclusions. The technique consists of imagining as many
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different ways the world could be (theories, models, ways of talking) as we
02
possibly can, and then observing the world as carefully as possible.
03
This broad characterization includes not only the obviously recognized
04
sciences like geology and chemistry but social sciences like psychology and
05
economics, and even subjects such as history. It’s not a bad description of
06
how many people typically figure things out about the world, albeit in a
07
somewhat less systematic way. Nevertheless, science shouldn’t be simply
08
identified with “reason” or “rationality.” It doesn’t include math or logic,
09
nor does it address issues of judgment, such as aesthetics or morality. Sci-
10
ence has a simple goal: to figure out what the world actually is. Not all the
11
possible ways it could be, nor the particular way it should be. Just what it is.
12
There’s nothing in the practice of science that excludes the supernatural
13
from the start. Science tries to find the best explanations for what we ob-
14
serve, and if the best explanation is a non- natural one, that’s the one science
15
would lead us to. We can easily imagine situations in which the best expla-
16
nation scientists could find would reach beyond the natural world. The
17
Second Coming could occur; Jesus could return to Earth, the dead could
18
be resurrected, and judgment could be passed. It would be a pretty dense
19
set of scientists indeed who, faced with the evidence of their senses in
20
such a situation, would stubbornly insist on considering only natural
21
explanations.
22
The relationship between science and naturalism is not that science pre-
23
sumes naturalism; it’s that science has provisionally concluded that natural-24
ism is the best picture of the world we have available. We lay out all of the
25
ontologies we can think of, assign some prior credences to them, collect as
26
much information we can, and update those credences accordingly. At the
27
end of the process, we find that naturalism gives the best account of the
28
evidence we have, and assign it the highest credence. New evidence could
The Big Picture Page 23