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about why we have these particular laws of physics at all. Why quantum
33
mechanics rather than classical mechanics? Why do we seem to have three
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dimensions of space and one of time, and the particular zoo of particles and
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forces we have discovered?
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It’s possible that some of these have partial answers within a larger
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physical context. Modern theories of gravity, for example, envision sce-
01
narios in which the number of dimensions of spacetime can be different in
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different parts of the universe. Perhaps there is some dynamic mechanism
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that picks out 4 as a special number.
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But that can’t be the entire answer. Why would there be such a dynamic
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mechanism in the first place? Physicists sometimes fantasize about discov-
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ering that the laws of physics are somehow unique— that these are the only
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ones there possibly could have been. That’s probably an unrealistic
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pipe dream. It’s not hard to imagine all sorts of different possible ways the
09
laws of physics could have been. Perhaps the universe could have been clas-
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sical, rather than quantum. Perhaps the universe could be a lattice, like a
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chessboard, with bits flipping from on to off as time passes in discrete units.
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Perhaps the sum total of reality could have been a single point, lacking ei-
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ther space or time. Perhaps there could be a universe that had no regulari-
14
ties at all, one where there would be nothing we would recognize as a “law
15
of physics.”
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There may be no ultimate answer to the “Why?” question. The universe
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simply is, in this particular way, and that’s a brute fact. Once we figure out
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how the universe behaves at its most comprehensive level, there will not be
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any deeper layers left to discover.
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Theists think they have a better answer: God exists, and the reason why
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the universe exists in this particular way is because that’s how God wanted
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it to be. Naturalists tend to find this unpersuasive: Why does God exist?
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But there is an answer to that, or at least an attempted one, which we al-
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luded to at the beginning of this chapter. The universe, according to this
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line of reasoning, is contingent; it didn’t have to exist, and it could have
26
been otherwise, so its existence demands an explanation. But God is a nec-
27
essary being; there is no optionality about his existence, so no further expla-28
nation is required.
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Except that God isn’t a necessary being, because there are no such things
30
as necessary beings. All sorts of versions of reality are possible, some of
31
which have entities one would reasonably identify with God, and some of
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which don’t. We can’t short- circuit the difficult task of figuring out what
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kind of universe we live in by relying on a priori principles.
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It’s important to be fair to both sides. Given a conventional understand-
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ing of what is meant by “God,” the fact that the universe exhibits
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01
regularities at all, and in particular that it exhibits regularities that allow
02
for the existence of human beings, seems to have a higher likelihood under
03
theism than under naturalism. A caring deity is more likely to produce hos-
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pitable conditions than a brute- fact cosmos. If the existence of a universe
05
governed by physical laws were the only piece of information we had, that
06
piece of evidence would tilt us in the direction of theism.
07
It’s not the only piece of evidence we have, of course. As we saw in chap-
08
ter 18, naturalists find many aspects of the universe that do not fit well at all
09
with theism, and count heavily against it. The theistic side of the argument
10
would be much stronger if it extended beyond “God would have wanted a
11
hospitable universe to exist, and here we are” to specific aspects of the phys-
12
ical world, especially ones we haven’t yet discovered. If you want to claim
13
that the properties of our kind of universe provide evidence for God’s exis-
14
tence, you need to believe that you understand God’s motivations well
15
enough to say that it’s more likely God would have created this kind of
16
universe rather than some other kind. And if that’s true, it’s natural to ask
17
for even more. How many galaxies would God have wanted to create?
18
What would God have made the dark matter consist of?
19
There may be answers to these questions, either in naturalism or in the-
20
ism. Or we may have to live with simply accepting the universe the way it
21
is. What we can’t do is demand explanations that the universe may not be
22
able give us.
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Body and Soul
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09
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11
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I
13
n another world, just slightly different from ours, the woman we know
14
as Princess Elisabeth of Bohemia might have been an influential and
15
celebrated philosopher or scientist. Instead, her ideas come to us pri-
16
marily from her correspondence with the great thinkers of her age, espe-
17
cially René Descartes. Known as virtuous and pious, in her later years she
18
served as an active leader of a major convent in Saxony. But she was most
19
distinguished by her freedom of thought and questioning intellect, which
20
led her to challenge one of Descartes’s most famous positions: m
ind- body
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dualism, the idea that the mind or soul is an immaterial substance distinct
22
from the body. If that were true, she insisted on knowing, how did the two
23
substances communicate with each other?
24
These days we would say it this way: our bodies are made of atoms,
25
which are in turn made of particles, and those particles obey the equations
26
of the Core Theory. If you want to say that the mind is a separate substance,
27
not just a way of talking about the collective effect of all those particles,
28
how does that substance interact with the particles? How are the equations
29
of the Core Theory incorrect, and how should we improve them?
30
31
•
32
In the early seventeenth century, the Holy Roman Empire was a loose con-
33
federation of city- states centered in modern- day Germany. One of the most
34
influential of them was the Electoral Palatinate, a group of municipalities
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scattered along the Rhine. Elisabeth Simmern van Pallandt was born there
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Elisabeth of the Palatinate, Abbess of Herford Abbey and
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Princess of Bohemia, 1618– 1680.
23
24
in 1618, daughter of Frederick V, Elector Palatine, and Elizabeth Stuart,
25
who herself was the daughter of James I of England. Elisabeth’s upbringing
26
seems tumultuous from our perspective, although perhaps it was a typical
27
Central European royal childhood back in those days.
28
Elisabeth didn’t grow up in Bohemia. After a short and unsuccessful
29
stint as the ruling couple of Bohemia, her parents sought refuge in the
30
Netherlands. Elisabeth was raised for a while by her grandmother in Hei-
31
delberg, before moving to The Hague at the age of nine with other members
32
of her exiled family. Through the upheaval she managed to obtain a wide-
33
ranging education, including philosophy, astronomy, mathematics, juris-
34
prudence, history, and classical languages, for which her fluency earned her
35S
the nickname “the Greek” among her brothers and sisters. Her father died
36N
when she was twelve, leaving her in the hands of an uninterested mother
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who would tease Elisabeth for her earnest, studious demeanor. Her life at
01
home was probably not made any smoother by her penchant for valuing
02
honesty over courtly manners.
03
Despite not living an easy or luxurious life by princess standards, Elisa-
04
beth managed to be active and engaged both intellectually and politically.
05
She was committed to social justice, befriending and supporting William
06
Penn and other influential Quakers, notwithstanding the theological dif-
07
ferences they may have had with her own Calvinism. She received one re-
08
corded offer of marriage, to the elderly King Wladyslaw IV of Poland,
09
whom she had never met in person. The Polish Diet wouldn’t let the match
10
go forward unless Elisabeth converted to Catholicism, which she refused
11
to do, so the wedding was called off.
12
In 1667 she entered the convent of Herford Abbey, where she eventually
13
rose to the station of abbess. Elisabeth wasn’t the retiring sort of nun, but
14
rather was an active philanthropist and humanitarian, offering the abbey
15
as a place of refuge for anyone persecuted for reasons of conscience, as well
16
as essentially governing the surrounding town. She died in 1680, having
17
become gravely ill, but not before putting her affairs in order and writing a
18
letter of farewell to her sister Louise.
19
20
•
21
In our actual world, René Descartes certainly succeeded in becoming an
22
influential and celebrated philosopher and scientist. As we have seen, he
23
delved deep into skepticism of the physical world, ultimately relying on his
24
belief in his own existence (and in God’s) to pull himself up by his boot-
25
straps. But at the moment our concern is with Descartes’s mind- body
26
dualism.
27
It was in the Meditations on First Philosophy, the same work in which he
28
established his own existence, that Descartes argued for the idea that the
29
mind is independent of the body. It’s not a completely crazy thing to think.
30
Both living organisms and nonliving objects clearly have “matter” in them,
31
but conscious creatures are manifestly different in some important way
32
from non- conscious lumps of stuff. The mind or the soul seems, at very first
33
glance, to be something quite different from the body itself.
34
Descartes’s argument was pretty simple. He’d already established that
S35
we can doubt the existence of many things, even the chair we are sitting on.
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So there’s no real problem doubting the existence of your own body. But
02
you can’t doubt the existence of your mind— you think, therefore your
03
mind must really exist. And if you can doubt the existence of your body but
04
not your mind, they must be two different things.
05
The body, Descartes went on to explain, works like a machine, having
06
material properties and obeying the laws of motion. The mind is an entirely
07
separate kind of entity. Not only is it not made of material stuff; it doesn’t
08
even have a specific location on the material plane. Whatever the mind is,
09
it’s something very different from tables and chairs, something that occu-
10
<
br /> pies an utterly distinct realm of existence. We label this view substance dual-
11
ism, since it claims that mind and body are two distinct kinds of substance,
12
not merely two different aspects of one underlying kind of stuff.
13
But the mind and body interact with each other, of course. Certainly
14
our minds communicate with our bodies, nudging them to perform this or
15
that action. Descartes felt that the interaction also went the other way: our
16
bodies can influence our minds. This was a minority position at the time,
17
although it also seems fairly unobjectionable at first glance. When we stub
18
a toe, it’s the body that is first affected, but our minds certainly experience
19
the pain. For a Cartesian dualist, minds and bodies coexist in an ongoing
20
dance of influence and response.
21
•
22
23
Elisabeth read Descartes’s Meditations in 1642, soon after they were first
24
published. She was intrigued, but skeptical. Fortunately for her, (1) Des-
25
cartes was himself living in the Netherlands at the time, and (2) she was a
26
princess. Before too long she was able to bring up her worries with the phi-
27
losopher himself.
28
Elisabeth’s father had died in 1631, leaving her mother, Elizabeth Stuart,
29
as the head of an indebted and unruly family. She would frequently host
30
salons that entertained politicians, scientists, artists, and adventurers. Des-
31
cartes attended one such event, at which Elisabeth was present, but the
32
studious young woman didn’t muster the courage to engage the famous
33
thinker in direct conversation. She did afterward speak of her interest in
34
Descartes’s recent writings to a mutual friend, who passed word along
35S
to him.
36N
Having royal allies is always a good thing, even if the family is out of
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power and relatively poor. Accordingly, on his next visit to The Hague,
01
Descartes once again stopped by the house of the exiled queen of Bohemia.
02
Elisabeth, as fate would have it, wasn’t in at the time. A few days later, how-
03
ever, he received a letter from her, the beginning of a correspondence that
04
would last until his death in 1650.
05
Elisabeth’s letters combine a mastery of formal etiquette with an intel-
06
lectual’s impatient distaste for beating around the bush. After a few polite
The Big Picture Page 36