31
of which disagrees with the others about what should be eliminated and
32
what should be kept.)
33
What is real, and what is not, doesn’t seem like an intractable problem
34
at first glance. The table in front of you is real; unicorns are not. But what
35S
if that table is made of atoms? Would it be fair to say that the atoms are real,
36N
but not the table?
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That would be a certain construal of the word “real,” limiting its appli-
01
cability to only the most fundamental level of existence. It’s not the most
02
convenient definition we can imagine. One problem is that we don’t, as yet,
03
actually have a full theory of reality at its deepest level. If that were our
04
standard for true existence, the only responsible attitude would be to say
05
that nothing that human beings have ever contemplated is actually real. It’s
06
a philosophy with a certain Zen purity, but it’s not very helpful if we would
07
like to use the concept of “real” to distinguish certain phenomena from
08
others. Wittgenstein would say that it doesn’t make sense to talk that way.
09
A poetic naturalist has another way out: something is “real” if it plays an
10
essential role in some particular story of reality that, as far as we can tell,
11
provides an accurate description of the world within its domain of applica-
12
bility. Atoms are real; tables are real; consciousness is undoubtedly real. (A
13
similar view was put forward by Stephen Hawking and Leonard Mlodi-
14
now, under the label “ model- dependent realism.”)
15
Not everything is real, even by this permissive standard. Physicists used
16
to believe in the “luminiferous aether,” an invisible substance that filled all
17
of space, and which served as a medium through which electromagnetic
18
waves of light traveled. Albert Einstein was the first to have the courage to
19
stand up and remark that the aether served no empirical purpose; we could
20
simply admit that it doesn’t exist, and all of the predictions of the theory of
21
electromagnetism go through unscathed. There is no domain in which our
22
best description of the world invokes the concept of luminiferous aether;
23
it’s not real.
24
25
•
26
Illusions are just mistakes, concepts that play no useful role in descriptions
27
at any level of coarse- graining. When you are crawling across the desert
28
sands, out of water and not completely in your right mind, and think you
29
see a lush oasis with palm trees and a pond in the distance— that’s an illu-
30
sion (probably), in the sense that it’s actually not there. But if you get lucky
31
and it really is there, and you scoop up liquid water into your hand, that
32
liquid is real, even if we have a more comprehensive way of talking that
33
describes it in terms of molecules made of oxygen and hydrogen.
34
Consciousness is not an illusion, even if we think it is “just” an emergent
S35
way of talking about our atoms each individually obeying the laws of
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01
physics. If hurricanes are real— and it makes sense to think that they are—
02
even though they are just atoms in motion, there is no reason why we should
03
treat consciousness any differently. To say that consciousness is real isn’t
04
to say that it’s something over and above the physical world; it’s emergent,
05
and it’s also real, just like almost every other thing we’ve encountered in
06
our lives.
07
08
Fundamental
Emergent/Effective Descriptions
09
10
Underlying
Physics,
Morality,
Aether,
11
Physical
Biology,
Aesthetics,
Phlogiston,
12
Reality
Psychology
Meaning
Unicorns
13
14
Real
Illusions
15
16
Factual/
Constructed/
17
Objective
Subjective
18
How poetic naturalism divides up “fundamental” versus “emergent/ effective,” “real”
versus “illusion,” and “objective” versus “subjective.”
19
20
21
Describing our naturalism as “poetic” is helpful because there are other
22
kinds of naturalism out there. There are austere forms of naturalism that
23
try to eliminate everything in sight, and insist that the only “true” way of
24
talking about the world is the deepest, most fundamental one. On the
25
other side of the spectrum are augmented forms of naturalism, which hold
26
that there is more to the world at a fundamental level than mere physical
27
reality. This is a grab- bag category that would include those who believe
28
mental properties are real and distinct from physical ones, or those who
29
believe that moral principles are as objective and fundamental as the physi-
30
cal world.
31
Poetic naturalism sits in between: there is only one, unified, physical
32
world, but many useful ways of talking about it, each of which captures an
33
element of reality. Poetic naturalism is at least consistent with its own stan-
34
dards: it tries to provide the most useful way of talking about the world
35S
we have.
36N
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•
01
02
The most seductive mistake we can be drawn into when dealing with mul-
03
tiple stories of reality is to mix up vocabularies appropriate to different ways
04
of talking. Someone might say, “You can’t truly want anything, you’re just
05
a collection of atoms, and atoms don’t have wants.” It’s tr
ue that atoms don’t
06
have wants; the idea of a “want” is not part of our best theory of atoms.
07
There would be nothing wrong with saying “None of these atoms making
08
up you want anything.”
09
But it doesn’t follow that you can’t have wants. “You” are not part of our
10
best theory of atoms either; you are an emergent phenomenon, meaning
11
that you are an element in a higher- level ontology that describes the world
12
at a macroscopic level. At the level of description where it is appropriate to
13
talk about “you,” it’s also perfectly appropriate to talk about wants and feel-
14
ings and desires. Those are all real phenomena in our best understanding of
15
human beings. You can think of yourself as an individual human being, or
16
you can think of yourself as a collection of atoms. Just not both at the same
17
time, at least when it comes to asking how one kind of thing interacts with
18
another one.
19
That’s the ideal case, anyway. Following Galileo’s lead of ignor-
20
ing complications and searching for simplicity, physicists have devel-
21
oped formalisms in which the separation between different ways of
22
talking—“effective field theories”— is precise and well-defined. Once we get
23
beyond physics to the more nuanced and complex realms of biology and
24
psychology, demarcating one theory from another becomes more difficult.
25
We can talk about human beings coming down with an illness and becom-
26
ing contagious, possibly passing on their disease to other people. “Illness”
27
is a useful category in our vocabulary for describing human beings, with a
28
reality all its own, independent of its microscopic underpinnings. But we
29
know that there is a deeper level according to which that illness is a mani-
30
festation of, for example, a viral infection. We can’t help but be sloppy and
31
mix up our talk of people and illnesses and viruses into one big messy vo-
32
cabulary.
33
Just as investigating dualities between different physical theories
34
provides full employment for physicists, investigating how different
S35
N36
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01
vocabularies relate to one another and sometimes intermingle provides
02
full employment for philosophers. For our purposes, we can leave that as
03
homework for the ontologically fastidious, and leap into a different ques-
04
tion: How do we go about constructing a set of ways to talk about our
05
actual world?
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35S
36N
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01
02
14
03
04
Planets of Belief
05
06
07
08
09
M
10
ost people don’t lose sleep worrying whether the world they see
11
is basically real, or whether they’re being tricked by an evil de-
12
mon. We accept that what we see and hear reflects reality with
13
at least some degree of reliability, and move on from there. This leaves us
14
with a more subtle problem: how do we construct a comprehensive picture
15
of how things work that is both reliable and consistent with our experience?
16
Descartes was looking for a “foundation” for justified belief. A founda-
17
tion keeps a structure firmly rooted in solid ground. Foundationalism is the
18
search for such solid ground, on which to erect the edifice of knowledge.
19
20
21
Science
22
23
Evidence of Our Senses
24
25
26
God, Omnipotent and Omnibenevolent
27
28
Cogito Ergo Sum
29
30
Knowledge as a series of beliefs resting on a secure foundation.
31
32
Let’s take that metaphor more seriously than it perhaps deserves. On the
33
scale of a human being, the ground beneath our feet is unquestionably solid
34
and reliable. If we zoom out a bit, however, we see that the ground is simply
S35
part of the planet on which we live. And that planet, the Earth, isn’t
N36
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01
grounded on anything at all; it is moving freely through space, orbiting
02
around the sun. The individual bits of matter that constitute the Earth aren’t
03
embedded in an unmoving structure; they are held together by their mutual
04
gravitational force. All of the planets in the solar system formed gradually,
05
as bits of rock and dust accreted together, each collection growing in influ-
06
ence and pulling together what remaining scraps of matter it could.
07
Without meaning to, we’ve discovered a much more accurate metaphor for
08
how systems of belief actual y work. Planets don’t sit on foundations; they hold
09
themselves together in a self- reinforcing pattern. The same is true for beliefs:
10
they aren’t (try as we may) founded on unimpeachable principles that can’t be
11
questioned. Rather, whole systems of belief fit together with one another, in
12
more or less comfortable ways, pulled in by a mutual epistemological force.
13
14
Many
15
Big
Worlds
Bang
16
Emergence
Abiogenesis
Poetic
17
Quantum
Earth,
Naturalism
Logic
Fields
18
Air,
Fire,
Practical
Bayesian
Death
Moral
Potency
19
Water
Wisdom
Inference
Constructivism
and Act
Conservation
20
Unmoved
of Information
Classical
Aether
Mover
Physicalism
21
Unities
Empathy
Eudaimonia
Determinism
22
Formal
Empiricism
Causes
Empiricism
Efficient
23
Causes
Virtue
24
Great
Chain of
25
Being
Teleology
Catholic
Cogito
Church
Ergo
26
Sum
God’s
27
Perfection
Mind/Body
Dualism
Inertial
Motion
28
Method
Analytic
29
of Doubt
Geometry
Interaction via
Pineal Gland
Foundationalism
30
The
Passions
31
Rationalism
Causal
32
Corpuscles
Adequacy
Vortices
Principle
33
34
Knowledge as a set of beliefs held together by the “gravitational pull” of their mutual 35S
consistency. Parts of the planets of belief for Aristotle, Descartes, and a modern poetic 36N
naturalist.
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Pl A n E t S O F b E l I E F
In this picture, a planet of belief is much richer and more complex than
01
simply an ontology. An ontology is a view about what really exists; a planet
02
of belief contains all sorts of other convictions, including methods for un-
03
derstanding the world, a priori truths, derived categories, preferences, aes-
04
thetic and ethical judgments, and more. If you believe that two plus two
05
equals four and chocolate ice cream is objectively better than vanilla, those
06
are not parts of your ontology, but they are parts of your planet of belief.
07
08
•
09
No analogy is perfect, but the planets-of-belief metaphor is a nice way to
10
understand the view known in philosophical circles as coherentism. Accord-
11
ing to this picture, a justified belief is one that belongs to a coherent set of
12
propositions. This coherence plays the role of the gravitational pull that
13
brings together dust and rocks to form real planets. A stable planet of belief
The Big Picture Page 20