The Big Picture
Page 26
06
construed, as far as theism is concerned?
07
It’s hard to doubt that the absence of evil would be taken as very strong
08
evidence in favor of the existence of God. If humanity simply evolved ac-
09
cording to natural selection, without any divine guidance or interference,
10
we would expect to inherit a wide variety of natural impulses— some for
11
good, some for not so good. The absence of evil in the world would be hard
12
to explain under atheism, but relatively easy under theism, so it would
13
count as evidence for the existence of God.
14
But if that’s true, the fact that we do experience evil is unambiguously
15
evidence against the existence of God. If the likelihood of no evil is larger
16
under theism, then the likelihood of evil is larger under atheism, so evil’s
17
existence increases our credence that atheism is correct.
18
Put in those terms, it’s easy to come up with features of our universe that
19
provide evidence for atheism over theism. Imagine a world in which mira-
20
cles happened frequently, rather than rarely or not at all. Imagine a world
21
in which all of the religious traditions from around the globe independently
22
came up with precisely the same doctrines and stories about God. Imagine
23
a universe that was relatively small, with just the sun and moon and Earth,
24
no other stars or galaxies. Imagine a world in which religious texts consis-
25
tently provided specific, true, non intuitive pieces of scientific information.
26
Imagine a world in which human beings were completely separate from the
27
rest of biological history. Imagine a world in which souls survived after
28
death, and frequently visited and interacted with the world of the living,
29
telling compelling stories of life in heaven. Imagine a world that was free of
30
random suffering. Imagine a world that was perfectly just, in which the
31
relative state of happiness of each person was precisely proportional to their
32
virtue.
33
In any of those worlds, diligent seekers of true ontology would quite
34
rightly take those aspects of reality as evidence for God’s existence. It
S35
N36
147
Big Picture - UK final proofs.indd 147
20/07/2016 10:02:43
T H E B IG PIC T U R E
01
follows, as the night the day, that the absence of these features is evidence
02
in favor of atheism.
03
How strong that evidence is, is another question entirely. We could try
04
to quantify the overall effect, but we’re faced with a very difficult obstacle:
05
theism isn’t very well defined. There have been many attempts, along the
06
lines of “God is the most perfect being conceivable,” or “God is the ground-
07
ing of all existence, the universal condition of possibility.” Those sound
08
crisp and unambiguous, but they don’t lead to precise likelihoods along the
09
lines of “the probability that God, if he exists, would give clear instructions
10
on how to find grace to people of all times and cultures.” Even if one claims
11
that the notion of God itself is well defined, the connection between that
12
concept and the actuality of our world remains obscure.
13
One could try to avoid the problem by denying that theism makes any
14
predictions at all for what the world should be like— God’s essence is mys-
15
terious and impenetrable to our minds. That doesn’t solve the problem— as
16
long as atheism does make predictions, evidence can still accumulate one
17
way or the other— but it does ameliorate it somewhat. Only at a significant
18
cost, however: if an ontology predicts almost nothing, it ends up explaining
19
almost nothing, and there’s no reason to believe it.
20
•
21
22
There are some features of our world that count as evidence in favor of the-
23
ism, just as some features are evidence for atheism. Imagine a world in
24
which nobody had thought of the concept of God— the idea had simply
25
never occurred. Given our definition of theism, that’s a very unlikely world
26
if God exists. It would seem a shame for God to go to all the trouble to cre-
27
ate the universe and humankind, and then never let us know about his ex-
28
istence. So it’s perfectly reasonable to say that the simple fact that people
29
think about God counts as some evidence that he is real.
30
That’s a somewhat whimsical example, but there are more serious ones.
31
Imagine a world with physical matter, but in which life never arose. Or a
32
universe with life, but no consciousness. Or a universe with conscious be-
33
ings, but ones who found no joy or meaning in their existence. At first
34
glance, the likelihoods of such versions of reality would seem to be higher
35S
under atheism than under theism. Much of the task of the rest of this book
36N
is to describe how these features are quite likely in a naturalistic worldview.
148
Big Picture - UK final proofs.indd 148
20/07/2016 10:02:43
A b du C t I n g g O d
There’s not much to be gained by rehearsing all of the arguments for and
01
against theism here. What matters more is understanding the basis for
02
making progress on this and similar questions. We lay out our prior cre-
03
dences, determine the likelihoods for different things to happen under each
04
competing conception of the world, and then update our credences on the
05
basis of what we observe. That’s just as true for the existence of God as it is
06
for the theory of continental drift or the existence of dark matter.
07
It all sounds very tidy, but we are fallible, finite, biased humans. Some-
08
one will argue that a universe with a hundred billion galaxies is exactly
09
what God would naturally create, while someone else will roll their eyes
10
and ask whether that expectation was actually put forward before we went
11
out and discovered the galaxies in our telescopes.
12
All we can hope to do is to survey our own planets of belief, recognize
&nbs
p; 13
our biases, and try to correct for them the best we can. Atheists sometimes
14
accuse religious believers of being victims of wishful thinking— believing
15
in a force beyond the physical world, a higher purpose to existence, and
16
especially a reward after death, simply because that’s what they want to be
17
true. This is a perfectly understandable bias, one we would be wise to rec-
18
ognize and try to take into consideration.
19
But there are biases on both sides. Many people may be comforted by
20
the idea of a powerful being who cares about their lives, and who deter-
21
mines ultimate standards of right and wrong behavior. Personally, I am not
22
comforted by that at all— I find the idea extremely off- putting. I would
23
rather live in a universe where I am responsible for creating my own values
24
and living up to them the best I can, than in a universe in which God hands
25
them down, and does so in an infuriatingly vague way. This preference
26
might unconsciously bias me against theism. On the other hand, I’m not at
27
all happy that my life will come to an end relatively soon (cosmically speak-
28
ing), with no hope for continuing on; so that might bias me toward it.
29
Whatever biases I may have, I need to keep them in mind while trying to
30
objectively weigh the evidence. It’s all any of us can hope to do from our
31
tiny perch in the cosmos.
32
33
34
S35
N36
149
Big Picture - UK final proofs.indd 149
20/07/2016 10:02:43
This page intentionally left blank
01
02
03
04
05
06
07
08
09
10
P A R t t h R E E
11
12
E S SE nC E
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
S35
N36
Big Picture - UK final proofs.indd 151
20/07/2016 10:02:43
This page intentionally left blank
01
02
19
03
04
How Much We Know
05
06
07
08
09
10
11
12
W
13
hen I was twelve years old, I was fascinated by psychic powers.
14
Who wouldn’t be? It’s a provocative notion, to be able to reach
15
out and push things around, hear what other people are think-
16
ing, or tell the future, all just by using your mind.
17
I read everything I could find about ESP, telekinesis, clairvoyance,
18
precognition— the whole gamut of mental abilities that stretched beyond
19
the ordinary. I was a big fan of comic books, where all the heroes were en-
20
dowed with superpowers, but also of science- fiction and fantasy stories, not
21
to mention straightforwardly “scientific” accounts of what purported to be
22
evidence for human capabilities beyond the normal. I wanted to penetrate
23
the mystery, figure out how this kind of thing could really work. I loved
24
mind- bending ideas, and what’s more mind- bending than the possibility
25
that the mind itself can actually bend things?
26
I was also a young scientist at heart. So eventually I decided on the obvi-
27
ous course of action— I would perform my own experiments.
28
We had a spare room in the ground floor of our house. There I was with
29
the door closed, the rest of my family occupied elsewhere. (I didn’t say I was
30
an especially courageous young scientist.) I started with small things like
31
dice and coins, placed carefully on a smooth tabletop. Then I just . . . thought
32
at them. I concentrated as hard as I could, trying to push the little trinkets
33
across the table with the sheer force of my mind. Sadly, nothing. I switched
34
to easier targets: tiny scraps of paper that shouldn’t require as much force to
S35
N36
153
Big Picture - UK final proofs.indd 153
20/07/2016 10:02:43
T H E B IG PIC T U R E
01
get moving. In the end I had to admit it: maybe some people were able to
02
push things around just by thinking, but I wasn’t one of them.
03
As experiments go, this wasn’t the most careful one ever performed. But
04
it was convincing to me at the time. I gave up on the idea that I could move
05
things around with my mind, and became pretty skeptical of anyone else
06
who claimed to have such powers. I didn’t lose my fascination for mind-
07
bending ideas, or penetrating deep mysteries. I still wish it were true that I
08
could move objects by thinking at them. It would be really useful, not to
09
mention scientifically fascinating.
10
•
11
12
A great deal of investigation, more professional than mine, has gone into
13
evaluating the possibility of psychic or paranormal phenomena. J. B. Rhine,
14
a professor at Duke University, famously carried out a long series of tests
15
that concluded that psychic powers were real. His studies were extremely
16
controversial; many attempts to replicate them failed, and Rhine was criti-
17
cized for having lax protocols that would allow subjects to cheat on his
18
tests. Today, parapsychology is not taken seriously by most academics. The
19
magician and skeptic James Randi has offered a million dollars to anyone
20
who can demonstrate such abilities under controlled conditions; many have
21
tried to claim the prize, but to date no one has succeeded.
22
And nobody ever will succeed. Psychic powers— defined as mental abil-
23
ities that allow a person to observe or manipulate the world in ways other
24
than through ordinary physical means— don’t exist. We can say that with
25
<
br /> confidence, even without digging into any controversies about this or that
26
academic study.
27
The reason is simple: what we know about the laws of physics is suffi-
28
cient to rule out the possibility of true psychic powers.
29
That’s a very strong claim. And more than a little bit dangerous: the
30
trash heap of history is populated by scientists claiming to know more than
31
they really do, or predicting that they will know almost everything any
32
day now:
33
34
“[We are] probably nearing the limit of all we can know about
35S
astronomy.”
36N
— Simon Newcomb, 1888
154
Big Picture - UK final proofs.indd 154
20/07/2016 10:02:43
h OW M u C h W E K n OW
“The more important fundamental laws and facts of physical
01
science have all been discovered.”
02
— Albert Michelson, 1894
03
04
“Physics, as we know it, will be over in six months.”
05
— Max Born, 1927
06
07
There is a 50 percent chance that “we would find a complete
08
unified theory of everything by the end of the century.”
09
— Stephen Hawking, 1980
10
11
My claim is different. (That’s what everyone says, of course— but this
12
time it really is.) I’m not claiming that we know everything, or anywhere
13
close to it. I’m claiming that we know some things, and that those things are
14
enough to rule out some other things— including bending spoons with the
15
power of your mind. The reason we can say that with confidence relies heav-
16
ily on the specific form that the laws of physics take. Modern physics not
17
only tells us that certain things are true; it comes with a built-in way of
18
delineating the limits of that knowledge— where our theories cease to be
19
reliable. To see how that works, in this section we’ll dig into the rules by
20
which contemporary physics says the universe operates.
21
22
•
23
My twelve- year- old self wasn’t really being overly optimistic, given his
24
knowledge at the time. The idea that our minds can reach out and influence
25
or observe the outside world seems completely plausible. We see things in
26
one place affecting things far away every day. I pick up a remote control,
27
push some buttons, and my TV comes to life and changes the channel. I