“Why These Laws?”— - Specialized Research AI at MIT

“Why These Laws?”—
Multiverse Discourse as a
Scene of Response

Jacob Pearce
University of Melbourne

This paper traces the emergence of “why” questions in modern cosmology and
the responding proliferation of multiverse discourse in the late twentieth and
early twenty-ﬁrst centuries. Critics who see speculative theorizing as delving
into the metaphysical are not hard to ﬁnd. George Ellis’ concern that we are
entering a new era of ‘cosmological myth’ resonates with the 1937 debate re-
garding “cosmythology” and the shifting boundary between physics and meta-
physics. However, the charge that multiverse proposals are nothing but
speculative metaphysics can be considered in terms other than criteria relating
to empirical testability. A historicist reading of what metaphysics represents in
this context is presented in order to emphasize that “metaphysical” as a pejo-
rative term in science discourse is a ﬂuid and historically contingent concept. It
appears that proposals are being considered metaphysical precisely when there is
no consensus on what constitutes empirical testability. Drawing on the work of
Nicholas Jardine, Hans-Jörg Rheinberger and Christopher Hookway, I argue
that in cosmology during this period, particularly in relation to multiverse
proposals, there appears a well-deﬁned “scene of response”, rather than of
fully-ﬂedged inquiry. Thus, intelligible questions may be considered meta-
physical, but not timelessly so.

Introduction

1.
By the end of the twentieth century, many prominent cosmologists were
fascinated by the questions why is the universe the way it is, and why does
the universe appear to be just right for life to emerge.1 Indeed, the shift to

1. For example, Bernard Carr’s edited volume Universe or Multiverse? comprises an im-
pressive list of contributions from many prominent cosmologists. While they propose dif-
ferent ways of how one goes about answering the question, they all seem to agree on the
pressing question itself: why is the universe the way that it is (Carr 2007).

Perspectives on Science 2017, vol. 25, no. 3
© 2017 by The Massachusetts Institute of Technology

doi:10.1162/POSC_a_00245

324

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posing questions beginning with why rather than what or how is a rela-
tively recent development in modern cosmology. This paper begins by
looking at the emergence of why questions in cosmological discourse by
tracing afﬁliated anthropic reasoning and ﬁne-tuning arguments in cosmol-
ogy. I also consider recent suggestions that the laws of physics may them-
selves evolve. In response to the why questions, this paper then examines
the proliferation of multiverse discourse in the late twentieth century.

Different interpretations of what the term multiverse signiﬁes are pre-
sented. I consider why these positions are so often charged with being
metaphysical. I argue that “metaphysical” as a pejorative term in cosmo-
logical discourse is a ﬂuid label, which relies on historically contingent
epistemologies (relating to the intelligibility of questions) and practices
(relating to the tractability of questions). A historicist understanding of
what the term metaphysical represents is presented, according to which
cosmology is often charged with delving into metaphysics when it at-
tempts to grapple with questions for which there is no agreement on
the methods and techniques for getting to grips with such questions.
Here, I take inspiration from Nicolas Rasmussen’s reading of Nicholas
Jardine’s Scenes of Inquiry:

Despite their differences, the traditional types of history of science
have something in common, both the positivistic strain … and also
the theory-driven strain… That is, both tell the history of science as
a progressive series of solutions (inventions, discoveries) or answers
(theories, models) to questions about the nature of the universe and
how best to master it. With few exceptions, the history of the
motivating questions has been told only incidentally, if at all… In
Scenes of Inquiry, Nicholas Jardine has taken the innovative step toward
resolving these difﬁculties by recasting them as problems concerning
the history of scientiﬁc questions. (Rasmussen 1997, pp. 10–1)

Following Rasmussen (and Jardine), I approach the history of cosmol-
ogy through the lens of the shifting questions, problems, solutions, prac-
tices, and presuppositions of inquirers. For Jardine, a scene of inquiry is a
meta-concept that designates the set of questions, which are deemed real
for a community of inquirers; the range of questions that it seems appro-
priate to pose. The reality of these questions depends on the ability of the
community of inquirers to get to grips with them, both intellectually and
practically (Jardine 2000, p. 4). The understanding of questions requires
conceptual preconditions, and answering questions requires certain prac-
tices. Scientiﬁc theories, then, can only gain traction when the inquirers
are able to tackle certain questions in their local reality. In this sense, we

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Why These Laws?

can see the emergence of certain cosmological theories as responses or solu-
tions to certain kinds of questions or lines of inquiry. Thus, when considering
the scene of cosmological inquiry, both its conceptual and practical aspects
are important. In order to have a uniﬁed and fully-ﬂedged scene of inquiry,
research questions ﬁrst need to be intelligible to the community. However,
and perhaps more importantly, the questions and problems are made tracta-
ble by deploying tools, techniques, methods and epistemic practices that pro-
duce phenomena, observations or theoretical conclusions, and allow inquirers
to get to grips with what they are investigating. If the tractable aspect is ab-
sent, there is confusion and debate in the community and potential contes-
tation regarding questions of epistemology and methodology.

This paper covers a relatively lengthy period, from the late 1980s until
the present day. During this time, cosmology has begun to encroach on
territory traditionally reserved for religion or speculative metaphysics.
Through the publication of more popular books, cosmology has also
permeated the public’s awareness with tantalising metaphysical answers
to the ultimate questions. I argue that this period is characterized by a
well-deﬁned scene of response rather than one of inquiry. Jardine identiﬁes
periods in science where there are no ways of getting to grips with the
intelligible questions. Christopher Hookway outlines: “These are the ques-
tions that are real in a stronger sense: they are experienced as needing an
answer (rather than just possessing one)” (Hookway 2008, p. 18). The in-
quirers, (with the conviction that an answer will be found), begin to look
for answers elsewhere or with other methods and techniques (Hookway
2008). A particular dimension has opened up, and questions such as
“why these laws of physics?” and “why this universe?” have become legit-
imate lines of inquiry. There are meta-debates concerning the legitimacy of
certain methods and techniques, and the inquirers are not sure how to get to
grips with concepts such as the multiverse. Goals are driving techniques,
and the scene of inquiry is in a state of ﬂux.

The aim of this paper is not to offer a prescriptive articulation of exist-
ing failings in the methodology and/or epistemology of modern cosmology
and to drive research directions. Rather, the paper treats the intellectual
history of cosmology in the spirit of historical epistemology in the terms
set out by Hans-Jörg Rheinberger—as an investigation into “the historical
conditions under which, and the means with which, things are made into
objects of knowledge” (Rheinberger 2010, p. 2). While the term historical
epistemology has been used for a wide variety of different intellectual ap-
proaches that have emerged in recent years, it was pioneered by French
thinkers such as Gaston Bachelard and Georges Canguilhem (Strum and
Feest 2011). From this perspective, there are certainly no timeless forms
of pure reason. Science (indeed the multiple sciences) becomes fragmented

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over time due to historical developments and contingencies. The norms of
scientiﬁc practice and the content of scientiﬁc knowledge are the products
of these long and convoluted histories, regardless of any claims to truth.
There is no eternal, unchanging, objective, absolute form of scientiﬁc ra-
tionality. The fundamental tenet is that in order to understand what sci-
ence is philosophically, we have to study its history.

The spirit of a historicization of Kantian critique could also characterize
this approach; that is, reading Kant’s conditions of possibilities in terms of
dynamic, rather than timeless categories.2 Namely, what are the (historical,
diachronic) conditions of the possible certain types of knowledge?
Rheinberger characterizes a great deal of the philosophy of science in the
twentieth century, from Ernst Mach onwards, in this way. Rheinberger
argues that several philosophers and historians of science have worked
towards historicizing epistemology to the point where the undertaking is
no longer concerned with what people simply believed. Instead, this concep-
tion sees science as a ﬂuid, cultural practice, and attempts to uncover the
conditions under which the vast, multifaceted sciences were shaped and
transformed over time (Rheinberger 2010, p. 10).

Finally, I want to stress that the ideas discussed in this fascinating most
recent period of modern cosmology (in this paper) are not entirely accepted
by mainstream cosmologists. There is a great deal of observational and the-
oretical work going on in cosmology debates across the world, which
focuses on the challenges posed by generally accepted observational relics
and experimental simulations. Issues such as the nature of dark matter and
dark energy for instance, based on observational data, are at the forefront of
many cosmological endeavours. The increasing use of computer simulations
in certain aspects of cosmology, such as galaxy formation and dynamics, has
supplemented existing methods of extrapolation, and has made many
problems which could not be solved by analytical methods tractable.3

However, the left-ﬁeld aspects of cosmological inquiry presented here
are not just on the periphery of mainstream cosmology. As Helge Kragh
has noted, “the debate concerning the multiverse is more than an innocent
pastime of a few cosmologists of a speculative inclination” (Kragh 2009,
p. 549). The notion of a multiverse is a serious cosmological consideration

2. Here, I follow the re-readings of Kant by Hans Reichenbach and Ernst Cassirer in the early
1920s, as they worked towards relativizing Kant’s notion of the a priori. See (Reichenbach
[1928] 1958, [1920] 1965, Cassirer [1929] 1957, Friedman 1999).

3. This appears to be an under researched area of the history of modern astrophysics.
Simulations began to be used seriously by the early 1970s, when the ﬁrst computer models
of galaxies started to emerge, but more research is required into how these techniques
transformed the scene of modern cosmological inquiry. For some relevant literature, see
(Winsberg 2010), (Sundberg 2012).

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Why These Laws?

in many circles, even if some cosmologists are highly skeptical of its legit-
imacy. Kragh agrees that there appears to be a major epistemic shift in
cosmological circles, especially as cosmology is being inﬁltrated with ques-
tions and practices from theories of quantum gravity. “As witnessed by
such new branches as multiverse cosmology, astrobiology, string-based
pre-big bang cosmology, and ‘eschatological physics’, scientiﬁc specula-
tions are highly regarded by many physicists and seen in a different, more
positive light than earlier” (Kragh 2009, p. 530).

The Emergence of “Why” Questions

2.
2.1. Anthropic Motivations and Fine-Tuning Discussions
It seems that the emergence of these why questions can be traced to the
mid-1970s with considerations of the anthropic principle in cosmological
circles. Anthropic reasoning is now well and truly a part of modern cos-
mology, even though it has its fair share of critics. Remaining one of the
more controversial tenets of modern cosmology, the anthropic principle
comes in many forms: from the weak—we would not be here to notice
that conditions are right for life if they were not right for life; to the
strong—as we are here, the universe must be such that intelligent life
forms evolve; to the participatory—only universes with observers at some
point in their history will become real; to the ﬁnal—intelligent life is a
necessary property of universes, and cannot be destroyed once it comes into
existence; to the completely ridiculous anthropic principle (CRAP), as
coined by Martin Gardner (Gardner May 8, 1986). Today, several eminent
scientists, including Stephen Hawking, Andrei Linde and Leonard
Susskind, see the weak anthropic principle, in some form, as essential
(Susskind 2006, pp. 22, 353).

The term anthropic principle was ﬁrst introduced by Brandon Carter in
1973, discussing large number coincidences in physics and cosmology.
Carter gave a talk at the 1973 International Astronomy Union (IAU) Sym-
posium honouring Copernicus’s 500th birthday in Krakow, and published
the talk in the 1974 conference proceedings (Carter 1974). Carter’s empha-
sis was on possible explanations, rather than predictions, for why the uni-
verse is the way that it is. He stated that he was inﬂuenced by Bondi’s
1959 Cosmology, in which “certain widely known ‘large number coinci-
dences’ are listed as evidence justifying the introduction of various exotic
entities” (Carter 1974). The other inspiration came from a 1961 paper by
Robert Dicke. Dicke discussed favourable conditions and the prerequisites
for our existence and argued that life could not exist if the universal con-
stants differed only slightly (Dicke 1961). A landmark book was published
in 1986 by John Barrow and Frank Tipler (Barrow and Tipler 1986), and
despite diverging from Carter’s formation signiﬁcantly, this work became

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Perspectives on Science

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the most cited reference for the anthropic principle,4 and inspired many
more philosophically-minded authors to discuss it as well (even if it was
widely ridiculed by cosmologists).5 Anthropic reasoning recognizes the
fact that the universe seems so ﬁne-tuned for life (as we know it), and uses
this fact to explain numerous physical phenomena that would otherwise be
difﬁcult to explain. If some of the fundamental physical constants of the
universe were altered only slightly, the universe would not have evolved to
the state we see it today, and the existence of life would be impossible.

The more cosmologists began thinking about the large coincidences
that seemed to produce the incredibly unstable set of conditions suitable
for life in our universe, the more seriously they articulated the question.
This ﬁne-tuning problem, as it came to be known, relates to the effect that
a slight modiﬁcation of physical constants would have on the evolution of
the universe. Had the universe expanded at a slightly greater rate, for in-
stance, no galaxies would have formed. If the rate of expansion were slightly
reduced, the universe would have collapsed in on itself a fraction of a second
after the Big Bang. So it appears that our universe has the conditions that
are just right for the development of galaxies, solar systems, and eventually,
life. Some have said that the values are so ﬁne-tuned that they are balancing
on a knife’s edge (Leslie 1989). Many parameters of the Standard Model
of cosmology and the fundamental physical constants exhibit these ﬁne-
tuning aspects (Carter 1974). The other, perhaps more alarming fact appre-
ciated by the early 1990s, was that the cosmological constant is roughly
120 orders of magnitude smaller than predicted by the Standard Model
of particle physics (Carroll et al. 1992, Hawking 1983, Weinberg 1987).
Moving away from these life-friendly (biophillic) formulations, practicing
cosmologists began to seriously pose questions for possible inquiry, such as,
why are the constants of nature what they are?

Philosopher Nick Bostrom explains that ﬁne-tuning arguments nor-
mally take the form of either a design hypothesis (where these values in
our universe are the result of purposeful design), or an ensemble hypothesis
(where our universe is just a tiny fraction of the entire totality of physical
existence or multiverse, which is sufﬁciently large and varied so ﬁne-tuning
becomes redundant) (Bostrom 2002). In the spirit of this second option,
some cosmologists began explaining ﬁne-tuning by positing an inﬁnite
set of universe domains with different physical laws and parameters. Then,
somewhere, things will work out just right for life (Rees 1999, Susskind 2006).

4. In 2011, Carter’s paper had 226 citations, whereas the Barrow and Tipler book had
1740. (Ellis 2011). Nevertheless, this high citation index is probably misleading—this
book was largely ignored and ridiculed by cosmologists.

5. For a survey of the publications and presentation up to 1991, see (Balashov 1991).

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Why These Laws?

Many popular science books emerged in the ﬁeld of cosmology in the
late twentieth century, attempting to get at the deep why questions
(Hawking and Mlodinow 2010, Susskind 2006, Krauss 2012). In Just
Six Numbers (published in 1999), Martin Rees argued that in order for life
to exist, the following six constants must be set: the ratio of the electrical
force divided by the gravitational force, the strength of nuclear binding,
the normalized amount of matter in the universe, the seeds for cosmic
structures, and the number of spatial dimensions. The overall structure
of the physics, though, remains unchanged (Rees 1999). Indeed, so many
values and parameters in cosmology would change the universe as we know
it if tinkered with even minutely. Authors such as Hawking and Mlodinow,
Krauss and Susskind make grand claims. In The Grand Design, Hawking
and Mlodinow, for example, state that physics is now able to answer
questions such as “Why is there something rather than nothing? Why do
we exist? Why this particular set of (physical) laws and not some other?”
(Hawking and Mlodinow 2010, p. 10).

Anthropic reasoning and ﬁne-tuning arguments in cosmology shifted
the focus for many inquirers away from the speciﬁcs of the physical history
of the universe, and towards questions of meaning. George Ellis argues
that “the more the issue of ﬁne tuning was investigated, the more pressing
it became” (Ellis 2011, p. 3216). There were just too many restrictions on
physical parameters to ensure that life as we know it could emerge in the
historical evolution of the universe.

It is important to distinguish that there were two closely inter-related
questions that became pressing to the community at this time: (i) Why are
the laws of physics (and constants) the way they are? (ii) Why are the laws
of physics (and constants) just right for life? Both questions have emerged
out of anthropic motivations and ﬁne-tuning discussions. While the
second led to other issues around biophillic principles, the ﬁrst had an impact
on the emergence of interest in the idea of the evolution of physics laws.

2.2. Evolving Laws of Physics?
In 1988, Geoffrey Burbidge (known for his non-standard work on Quasi-
Steady State Theory), criticized the community for only accepting, “far-out
theoretical ideas” if they were “related to the very early universe. There,
anything and everything goes” (Burbidge 1988 p. 225). He argued that
interesting questions remained (at least for him) regarding more radical
theoretical ideas, such as the notion that the laws of physics themselves
may have evolved. In 1988, he noted that “The current climate of opinion
requires that these questions not be asked” (Burbidge 1988 p. 225).

However, by the early twenty-ﬁrst century, physicists were beginning to
take such notions seriously. In a paper published in 2013, physicist Lee

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Smolin made some germane suggestions concerning how and why these
questions have become pressing. Smolin claimed that, “As our knowledge
of the elementary particles and fundamental interactions grew dramatically
during the twentieth century we began to be interested in questions that
are not answered by knowing the laws of physics. One of these is the ques-
tion: why are these the laws, rather than other possible laws?” (Smolin 2013,
p. 24). In discussing the shift from how to why, Smolin began thinking
about why these laws of physics became the laws in our universe: “If there
are many possible laws, each as logically consistent as those we observe,
what selected the set that are realized in our universe? Another question
not answered by knowing the laws is what selected the initial conditions,
at or near the big bang” (Smolin 2013, p. 24). Here it would seem that
metaphysics and cosmology come together.

Thinking about the question “why is an object the way it is?,” a num-
ber of ways of answering it appear possible. One can give an answer in
terms of the object’s history: a historical or evolutionary story can be given
for instance, on why a mountain range or the solar system, or a particular
biological organism, has the particular features it does. Indeed, the features
of the universe as a whole are nowadays explained in terms of its historic-
ity. Another possibility is with a statistical explanation: due to some kind
of probability distribution, or variations in populations, certain objects or
classes of them can emerge (such explanations are given for thermodynamic
movements of gases, for example). These types of explanations are given by
some as suggestions that the universe emerged out of quantum ﬂuctuations
(Hawking and Mlodinow 2010). By the late twentieth century, objects
within the universe were typically explained in terms of their history
(Pearce 2017). However, the reasons for the beginnings of the universe,
and questions concerning why the universe is the way that it is, also became
realms for the application of historicist thinking.

Smolin probed the meta-questions associated with the shifts in the

scene of inquiry in the late twentieth century.

There are in science only two ways to explain why some state of
affairs has come about. Either there are logical reasons it has to be
that way, or there are historical causes, which acted over time to
bring things to the present state. When logical implication is
insufﬁcient, the explanation must be found in causal processes acting
over time. (2013, p. 24)

The problem with causal explanations here is that a causal process is
usually understood as meaning processes that act in accordance with laws.
If the laws themselves are the very things that require explanation, then we
get caught in a vicious circle. Different levels of laws can be postulated to

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Why These Laws?

account for presumably lower-level laws, but at some point, a set of fun-
damental laws would be needed to explain the others.

Smolin suggested that in cosmology today, there is no logical explana-
tion for why the universe is the way that it is. Smolin began thinking
about the laws of physics in terms of their historicity, and wondering
whether the current laws of physics are in fact the product of some earlier
epoch of the universe prior to the Big Bang.

In our analysis of the why these laws question we concluded that
laws must have evolved dynamically to be explained. This implies
that there were dynamical processes in our past by which the laws
evolved. As we do not see any evidence that the fundamental laws or
their parameters evolved in the observable past, these processes must
have gone on in regions yet unresolved observationally. (2013, p. 31)

As the causal process explanation is insufficient in this context, there
appears to be no alternative way of answering the why these laws question
without invoking the idea of evolving laws. In short, the laws of physics as
we know them today may in fact be dynamically changing over time.

The notion that the laws of physics may have evolved to their present
state is not new in physics, but it has not been the accepted position since
at least the middle of the twentieth century. In 1939, Paul Dirac famously
suggested that the laws of physics might not be static. “At the beginning
of time the laws of Nature were probably very different from what they are
now. Thus, we should consider the laws of Nature as continually changing
with the epoch, instead of as holding uniformly throughout space-time”
(Dirac 1939, p. 128). As early as 1891, the founder of American pragma-
tism, Charles Sanders Peirce argued that it is not sufﬁcient to simply know
the laws of nature—they require an explanation: “Law is par excellence the
thing that wants a reason. Now the only possible way of accounting for the
laws of nature, and for uniformity in general, is to suppose them results of
evolution” ([1891] 1955, p. 318).

These are answers to the question “why these laws?” which, although
ﬂagged long ago by these authors, were not even considered as possible
answers throughout the twentieth century. Now, in the twenty-ﬁrst
century, the possibility of answering these questions in this way has been
uncovered and is being re-assessed.

3. A Scene of Response?
3.1. Multiverse Proposals: a New Cosmological Discourse
Just as these why questions emerged in the scene of inquiry, based on an-
thropic motivations and ﬁne-tuning arguments, it is clear that the in-
quirers were not quite sure how to answer these. Questions became

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intelligible to the community—such as “Why are the laws of physics the way
they are?” and “Why are the laws of physics just right for life?”—but there
were no accepted strategies of inquiry that made these questions tractable. In
turn, what eventuated was that the questions themselves called for new tech-
niques to be developed. A new cosmological discourse around the notion of a
multiverse began to dominate the scene of cosmological inquiry, as it would
appear, in direct response to this dimension of the scene of inquiry that
opened up. Multiverse discourse became a critically important manifestation
of the changing scene of cosmological inquiry in the late twentieth century.
Speculating about possible multiple worlds is nothing new (Bettini
2005, Kragh 2009, pp. 534–35). Such ideas can be traced back to the
pre-Socratics (Anaximander and Anaximenes). However, these discussions
were around the notion of a plurality or inﬁnity of worlds. There are in-
stances of multiverse-type ideas from Giordano Bruno in the late Renais-
sance, however Bruno conceived of the universe as inﬁnite and his talk of
an “inﬁnity of worlds” was meant in terms of planets. There are also
multiverse-type notions present in the writings of Thomas Wright and
Immanuel Kant in the eighteenth century, and even physicist Ludwig
Boltzmann in 1895. Boltzmann proposed the existence of subuniverses
in connection with the law of entropy (Boltzmann 1895). Nevertheless,
all of these notions were distinctly uncharacteristic of the multiverse dis-
course, which emerged in the late twentieth century.

Although there were multiverse-like proposals around before 1980,
Kragh notes that they were “few and scattered” and “attracted little atten-
tion” (2009, p. 536). I focus on some of the ﬁrst serious multiverse pro-
posals from practicing cosmologists. Some of these appear in the very same
proceedings from the 1973 IAU Symposium mentioned earlier. The papers
at the symposium were, for the most part, dedicated to cosmological issues
relating to the recently established hot Big Bang model, which had be-
come well established in the community after the 1971 and 1972 publi-
cations of the Peebles and Weinberg textbooks (Peebles 1971; Weinberg
1972). Yet interestingly, there are two publications from the conference
that touched on the idea of universes distinct from our own. These are
Gary Steigman’s contribution, suggesting that “an ensemble of very many
possible universes” could solve the matter/antimatter conundrum (1974,
p. 355); and Stephen Hawking’s paper discussing “conceivable universes”,
while covering the observed isotropy of the universe (Hawking 1974,
p. 285). However, these explorations were not multiverses in the way that
they are conceptualized today.

Carter himself implied a multiverse in postulating the existence of “an
ensemble of universes characterized by all possible combinations of ini-
tial conditions and fundamental constants” (Carter 1970). For Carter, this

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Why These Laws?

conception did not go “very much further than the Everett doctrine” (1974,
p. 298; see Everett 1956, 1957). It also appears that Carter’s world ensemble
notion in his 1973 address made little initial impact. Carter explained that
the Everett interpretation of quantum mechanics described a vector state of
the Universe with “many branches of which only one can be known to any
well-deﬁned observer (although all are equally ‘real’)” (Carter 1974, p. 298).
This proposal is dramatically at odds with the modern conception of the
multiverse (in the string landscape), which is now in vogue (although highly
controversial). The Everett view conceived of multiverses that all have the
same laws of physics, whereas the laws and constants in the string landscape
view vary (but more on this later). Carter concluded that “this doctrine would
ﬁt very naturally with the world ensemble philosophy that I have tried to
describe” (1974, 298). Thus, Carter introduced the anthropic principle in
its ﬁrst modern form and connected it with an ensemble multiverse notion:
“an ensemble of universes characterized by all conceivable combinations of
initial conditions and fundamental constants” (Carter 1974).

Popular science books, such as Paul Davies’ Other Worlds (1980) ensured
that the public knew of the possible many-universe ideas that were emerg-
ing in cosmology. But as Kragh points out, “the majority of cosmologists
considered them heterodox and speculative” (Kragh 2009, p. 536). There
are a plethora of differing conceptions of the multiverse, but even more
speculative ways of generating them. For instance, in 2004, Tegmark pro-
posed a radial notion of the multiverse—that all possible mathematical
structures are realized physically; whatever is metaphysically or logically
possible cannot be ruled out (Tegmark 2004).6 String theorist Brian
Greene gave his own taxonomy, which covers nine types of parallel universes:
quilted, inﬂationary, brane, cyclic, landscape, quantum, holographic,
simulated and ultimate (Green 2011). In 2005, Stephano Bettini identiﬁed
at least 29 ways of generating multiverses and noted that any taxonomy of
multiverses would still miss other proposals:

Oscillations, quantum world-splitting or other forms of foliation of
Hilbert space, quantum vacuum ﬂuctuations, symmetry breaking
bubbles production, chaotic distributed scalar ﬁelds, inﬂaton’s ﬁelds,
wormholes, Smolin’s black holes, random difference of chaotic gauge
theories, moduli space of solutions of a supersymmetric M-theory,
primordial antimatter domains at high redshifts, … not to speak of
the idea of producing universes in the laboratory through ‘a small
region of false vacuum’, of cosmic organism’s theories or of the
suggestion concerning fake ‘simulated universes’ indistinguishable

6. This seems a recapitulation of Spinoza’s view that whatever is possible exists necessarily.

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from real ones in the eyes of their virtual inhabitants… Moreover
universes can generally differ not only in size or free parameters
typical of the Hot Big Bang model, but also in strength of
elementary forces, masses of elementary particles, gauge symmetries,
vacuum energy densities (i.e.: values of the cosmological constant),
metric signatures, dimensionality and so on, thus frustrating almost
any attempt of looking for an accurate taxonomy of the existing
multiverse scenarios. (Bettini 2005, pp. 4–5)

The most accepted physical idea in cosmology that implies a multiverse is
the inﬂationary scenario, which has more recently been closely linked to the
“string landscape”, and a range of other proposals emerging from what is now
termed string cosmology. These proposals came from a fusion of string theory
with cosmological questions. String theory emerged in the 1980s as the lead-
ing candidate for a theory to unify gravity with quantum mechanics, and in
doing so, brought the general theory of relativity and the Standard Model of
particles and fundamental forces under one overarching theoretical frame-
work.7 In its earlier versions, string theory claimed that the smallest constit-
uents of physical reality are miniature vibrating one-dimensional strings,
rather than particles, and different oscillations of the strings give rise to
the forces and particles in the universe. However theoretical developments
in the 1990s, most notably the discovery of d-branes and various dualities
(such as the AdS/CFT duality) and the postulation of an 11-dimensional
M-theory, have obscured this simple ontology underlying string theory. It
no longer makes sense to say the fundamental ontology is string-like (Duff
et al. 1995). The extra spatial dimensions (aside from our standard four-
dimensional space-time), deemed necessary for consistent versions of string
theory, are thought to be hidden through a process of “compactiﬁcation”, in
which the extra dimensions are “curled up” on themselves.

For around 20 years after the mid-1980s, inﬂationary cosmologists spec-
ulated about different models of a multiverse or set of quasi-universes. In
2000, in the wake of the discovery of the positive cosmological constant,
Polchinski and Bousso ﬁrst calculated that the basic string theory equa-
tions have an enormous number of possible solutions (around 101000)
and each solution represents a unique set of fundamental constants, with
particles and forces constituting the universe (Bousso and Polchinski
2000);8 the ﬁgure is now usually given as around 10500. This so-called

7. For more detailed analysis of string theory and its history, see Rickles 2014.
8. The statistics of the string/M theory vacua are treated thoroughly by Michael Douglas.

See (Douglas 2003).

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“landscape” is due to inﬂationary mechanisms and has been interpreted by
a number of prominent physicists, notably Linde, Susskind and Rees, as
“essentially distinct universes” ( Weinstein 2006, p. 1, Bousso and
Polchinski 2000, Susskind 2003). The fundamental physical parameters
are different in these universes, and some interpret this using anthropic
reasoning (Weinstein 2006). String theorists, working with supersymmet-
ric models linking to the Standard Model of cosmology, currently cite
10500 low-energy vacua solutions. While not all agree that these represent
other real universes, the string landscape is believed by many to represent
an “ultimate ensemble” type multiverse—though no exact correspondence
with our universe has ever been found.

The notion of an ultimate ensemble multiverse raises an important issue
within multiverse discourse. One ambiguity in most multiverse discourse
is deﬁning precisely what a multiverse means, especially in relation to the
meaning of the term universe. The term universe is often used to refer to
all that exists in a materialist sense of matter and energy, although it may
include all of space and time. More recently, cosmologists have used the
term universe to refer to the set of fundamental laws and physical constants
that govern our universe. A multiverse can thus refer to the different sets of
laws and constants that may operate at different times and in different re-
gions of the universe (being all that exists). So the multiverse in this for-
mulation represents different pockets of the same larger universe. Some
metaphysics is unavoidable here in a sense, as it remains necessary to ar-
ticulate the meaning of “existence”. So in presenting the universe as an
ensemble of pockets with different laws, it may just be that cosmologists
will need to more carefully deﬁne what they mean by universe. There ap-
pears to be an interesting shift in multiverse discourse away from a uni-
verse constituting all that exists (qua matter and energy) and towards a
universe representing one particular realm of physical laws.

Multiverse proposals were seen by many as a means for explaining the
ﬁne-tuning problem. This was a main driver of connecting anthropic rea-
soning with the multiverse. The fact that the parameters of the Standard
Model of cosmology exhibited ﬁne-tuning aspects, as mentioned earlier
(Carter 1974; Carroll et al. 1992; Hawking 1983; Weinberg 1987), im-
plied for many that no matter how delicate the balance of these values
appears to be, the fact that we live in a universe with them is somehow
important (Rees 1997). Bernard Carr explains:

These multiverse proposals have not generally been motivated by an
attempt to explain the anthropic ﬁne-tunings; most of them have
arisen independently out of developments in cosmology and particle
physics. Nevertheless, it now seems clear that the two concepts are

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inherently interlinked. For if there are many universes, this begs the
question of why we inhabit this particular one, and—at the very
least—one would have to concede that our own existence is a relevant
selection effect. Indeed, since we necessarily reside in one of the
life-conducive universes, the multiverse picture reduces the strong
anthropic principle to an aspect of the weak one. For this reason,
many physicists would regard the multiverse proposal as providing
the most natural explanation of the anthropic ﬁne-tunings.
(Carr 2007, p. 4)

While ﬁne-tuning was the problem that the multiverse proposal solved,
cosmic inﬂation was the physical mechanism by which the multiverse idea
became more seriously considered in the community (Kragh 2009,
p. 536). The link of inﬂation to a possible multiverse was ﬁrst proposed
in 1982 by Linde (Linde 1982) and followed by a more detailed discussion
in 1983 (Linde 1983b). It was proposed that the speed of the expansion of
the universe during inﬂation could have created areas of the universe,
which are in effect separate bubbles of space-time (or, subuniverses). An-
other paper by J. Richard Gott in 1982 explored inﬂationary cosmology as
a theory of multiple universes (Gott 1982). Linde’s 1983 paper connected
the universe with different properties corresponding to different vacua of
supersymmetric theories (Linde 1983a). The multiverse arising from the
inﬂationary model was then explicitly proposed by Linde in 1986 (Linde
1986). He covered the anthropic implications of eternal inﬂation on the
multiverse. The advances in string theory and the subsequent amalgam-
ation of the multiple string theories by M-theory brought with them more
support for the multiverse notion. This was despite the fact that there
remained no empirical veriﬁcation of string theory, nor any conceivable
observational tests on the horizon.

Vilenkin believes that eternal inﬂation means that the multiverse pic-
ture is essentially inevitable (Vilenkin 2007, p. 163). Others, like Ellis
dispute the claim that chaotic or eternal inﬂation implies a multiverse:

Some claim such a multiverse is implied by known physics, which
leads to chaotic inﬂation, with different effective physics necessarily
occurring in the different bubbles of chaotic inﬂation. But this is not
the case. The key physics (e.g. Coleman-de Luccia tunneling or the
hypothesized inﬂation potential, the string theory landscape) is
extrapolated from known and tested physics to new contexts; the
extrapolation is unveriﬁed and indeed is unveriﬁable; it may or may
not be true. For example, the parameter values that led to eternal
chaotic inﬂation may or may not be the real ones occurring in

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Why These Laws?

inﬂation, assuming that inﬂation happened. And in particular, the
supposed mechanism whereby different string theory vacua are
realized in different universe domains is speculative and untested.
(Ellis 2014, p. 15)

In a conference paper in 2006, Alan Guth explained “The combination of
the string landscape with eternal inflation has in turn led to a markedly
increased interest in anthropic reasoning, since we now have a respectable
set of theoretical ideas that provide a setting for such reasoning” (Guth
2006, p. 10).9 Even though the theories were speculative and the reason-
ing anthropic, they were generally becoming respectable.

To many physicists, the new setting for anthropic reasoning is a
welcome opportunity: in the multiverse, life will evolve only in very
rare regions where the local laws of physics just happen to have the
properties needed for life, giving a simple explanation for why
the observed universe appears to have just the right properties for
the evolution of life. The incredibly small value of the cosmological
constant is a telling example of a feature that seems to be needed for
life, but for which an explanation from fundamental physics is
painfully lacking. Anthropic reasoning can give the illusion of
intelligent design, without the need for any intelligent intervention.
(Guth 2006, p. 10).

Nevertheless, in 2006 Guth acknowledged that “many other physicists
have an abhorrence of anthropic reasoning” (Guth 2006, p. 10). Physicist
David Gross has argued that the recent trend towards embracing anthropic
reasoning and multiverse hypotheses by some string theorists is “prema-
ture and defeatist” (Gross 2005, p. 105). In a recent interview, Gross
has reiterated his objections to the notion of a multiverse and the deploy-
ment of anthropic reasoning—a view that is shared by a number of other
physicists (Byrne 2013).

Critics of the multiverse idea would no doubt disagree with the follow-
ing claim from cosmologist Max Tegmark: “The borderline between phys-
ics and philosophy has shifted quite dramatically in the last century … I
think it’s quite clear that parallel universes are now absorbed by that

9. Linde makes similar remarks: “I believe we are now entering ‘the age of anthropic
reasoning.’ Inﬂationary cosmology—in combination with strong theory—leads to a picture
of a multiverse consisting of an inﬁnite number of exponentially large domains (‘universes’)
with an exponentially large number of different properties. In addition to a somewhat sub-
jective notion of beauty and naturalness, we are adding the simple and obvious criterion
that the part of the Universe where we live must be consistent with the possibility of our
existence” (Linde 2007, p. 145).

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moving boundary. It’s included within physics rather than metaphysics”
(Seife 2004, p. 465). The question of what counts as demarcation remains
a hotly contested one. Similar to disputes in cosmological circles in the
1930s,10 the protagonists seem to get caught up in a demarcation dispute;
a dispute which goes right to the heart of the accepted tools of inquiry that
allow inquirers to get to grips with intelligible questions.11

3.2. Deﬁning Metaphysics in Terms of Historicity
Just as the questions became pressing, the tractability of the methods and
epistemic practices was tested. The most powerful tool that cosmologists
were able to apply in attempting to answer these questions was the very
tool that had been deployed successfully since 1980—speculative theoriz-
ing. Countless theoretical proposals were put forward, each more elaborate
than the last. Whereas the inﬂationary scenario immediately solved several
problems for standard Big Bang cosmology, and made the temporal evo-
lutionary narrative of the universe more consistent, multiverse proposals
did not solve problems in the evolutionary history of our universe. Rather,
if they did solve problems, they were not ones that had any direct bearing
on the history of our universe as we know it. Without accepted methods
or techniques to build evidence for any of the proposals, these speculative
theories remain metaphysical in the eyes of many. It will become clear that
the meaning of such a charge, however, is complex and somewhat ﬂuid.
Some cosmologists have expressed concerns that multiverse proposals
delve into metaphysics. Ellis, for instance, does not reject the idea of
multiverse altogether, and agrees that cosmologists “must explore all alter-
natives: Models based in the wave function of the universe; Pre-big bang
and cyclic cosmologies; Brane cosmology and string cosmology; Loop quan-
tum cosmology” (Ellis 2014, p. 17). However, “all of them are highly spec-
ulative untested physics, and most suffer from mathematical problems such as
ill deﬁnition, or divergences, or arbitrary assumption of a matter behavior
that is nothing like what we have ever encountered in a laboratory” (Ellis
2014, p. 17). Ellis also calls for caution in testing these theories in the
way described above, “only by matching the CMB [cosmic microwave back-
ground] anisotropies, which they all laudably strive to achieve … CMB pre-
dictions are crucial—they are necessary for a viable cosmological theory—but

10. The 1930s saw vehement debates regarding the legitimate methodology for dealing
with questions concerning cosmology. (Gale 2002; Gale and Shanks 1996; Gale and Urani
1999).

11. For an analysis of how this plays out in the context of string theory, see Ritson and

Camilleri 2014.

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Why These Laws?

by themselves are not sufﬁcient to establish any speciﬁc such theory” (Ellis
2014, p. 17).

Carr explains that some physicists reject the notion that the multiverse
is real science. “Since our conﬁdence in them is based on faith and aesthetic
considerations (for example mathematical beauty) rather than experimental
data, they regard them as having more in common with religion than sci-
ence” (Carr 2007, p. 14). Although this is a somewhat unsophisticated
simpliﬁcation of a multifaceted debate, the sentiment of Carr’s comment
is indicative of a general distrust towards multiverse discourse. This view
can be seen, for instance, in the work of physicists such as Ellis (2007),
Smolin (2007) and Martin Gardner (2003). Paul Davies, another critic
of the multiverse, regards the multiverse notion as just as metaphysical
as that of a divine creator (Davies 2007). Davies underscores that many
multiverse explanations are “reminiscent of theological discussions. In-
deed, invoking an inﬁnity of unseen universes to explain the unusual fea-
tures of the one we do see is just as ad hoc as invoking an unseen Creator.
The multiverse theory may be dressed up in scientiﬁc language, but in
essence it requires the same leap of faith” (Davies 2003).

There are concerns from the standard circles about the methodological
practices and metaphysical speculations in multiverse proposals. Ellis is
concerned that “cosmological myth” is taking over in these endeavors,
“but this time in a scientiﬁc rather than religious mode. By myth, I mean
an explanatory story or theory that gives means of understanding what
happens but remains hypothetical rather than proven” (Ellis 2008
p. 538). Writing in 2014, Ellis was also worried about cultural shifts in
cosmological circles:

Currently, there is a culture of allowing anything whatever in
speculative cosmological theories—sometimes abandoning basic
principles that have been fundamental to physics so far… claims
emanating from this approach should be regarded with great
caution: they are in many cases unsupported by evidence and are
based on arbitrary assumptions that don’t satisfy usual physical
criteria. (Ellis 2014, p. 17)

Ellis cautions cosmologists (and other physicists) against the claims
emanating from this approach: “Once the gold standard of experimental
support has been dropped and basic scientific principles are disregarded,
why should such theories be regarded as good science?” (2014, p. 17).

Bernard Carr notes:

Despite the growing popularity of the multiverse proposal, it must
be admitted that many physicists remain deeply uncomfortable with

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it. The reason is clear. The idea is highly speculative and, from both a
cosmological and a particle physics perspective, the reality of a
multiverse is currently untestable. Indeed, it may always remain so,
in the sense that astronomers may never be able to observe the other
universes with telescopes and particle accelerators. (2007, p. 14)

The issue of empirical testability is a crucial and complex one when
considering multiverse discourse, as possible multiverse-domains are by
deﬁnition, beyond the particle horizon of the visible universe. These realms
remain, therefore, unobservable even in principle. Critics of multiverse cos-
mology seem to ubiquitously draw on criteria relating to empirical test-
ability to reject multiverse proposals. There are caveats around this
observable boundary, and the only conceivable observational tests for the
multiverse proposals are in the form of remnants, relics, and signatures or
imprints in observable phenomena in our visible universe.

It is worth reﬂecting very brieﬂy on the observational veriﬁability of
multiverse proposals. Recent cosmological research has produced some of
the ﬁrst observational tests of eternal inﬂation, but the results are sketchy
at best. Some researchers have outlined an algorithm for simulating CMB
skies with and without collisions of possible bubble universes in a previous
point in some multiverse cosmic history. They look for promising signals
and perform searches for causal boundaries in the CMB; possible signatures
or imprints in the spectrum using real 7-year data from the Wilkinson
Microwave Anisotropy Probe ( WMAP). The researchers note that more
precise polarization data from the new Planck satellite is needed, but like
the BICEP-2 experiment ((BICEP2 Collaboration 2014a, b) See also
(Seljak and Zaldarriaga 1997)), it is difﬁcult to determine whether the sig-
natures are truly bubble collisions or in fact, just noise (Feeney et al. 2011).
This incredibly complex area of the observational corollaries of multiverse
scenarios requires further probing.

It is evident that the multiverse-related proposals in cosmology have
generated much debate. Critics who see speculative theorizing as delving
into the metaphysical are not hard to ﬁnd when examining string land-
scape discourse, for instance. However, the notion that opponents of the
multiverse must all also be Popperians or strict empiricists seems overly
simplistic. Drawing on notions of empirical testability, and challenging
the legitimacy of the very possibility of “in principle” empirical veriﬁca-
tion, seems to have become a neat rhetorical device that some cosmologists
employ to criticize views they disapprove of, but a device which is hardly
applied consistently across all areas of cosmology and, indeed, physics in
general. After all, many cosmologists happily accept the notion of inﬂation

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342

Why These Laws?

(which is yet to be empirically veriﬁed and, as Dawid has argued, is
“arguably more detached from empirical testing than any other current
theory” (Dawid 2013, p. 7)), but vehemently reject the multiverse. Count-
less other areas of cosmological inquiry have also been characterized as bor-
dering on the limits of metaphysics in previous times, but at later times
they seem to comfortably sit in the accepted realms of the scene of inquiry.
Notions such as the Big Bang, the very early universe, and realms beyond
the limits of our galaxy were all considered at previous times to be beyond
the limits of scientiﬁc inquiry.

The point I am trying to make is that the charge that claims multiverse
proposals are nothing but speculative metaphysics can be considered in
terms other than criteria relating to empirical testability. Applying a his-
toricist reading of what metaphysics means may help unpack what is going
on here, even if the actors in the scene of inquiry do not present it in these
terms. It appears that proposals are being considered metaphysical pre-
cisely when the methods by which testability is established are contested.
In other words, there is no consensus on what constitutes empirical test-
ability precisely when the means of inquiry are contested. From this view,
the debate regarding the legitimacy of multiverse proposals stems from
implicit disagreement regarding which tools of inquiry can and/or should
be used to answer the pressing why questions.

From the standpoint of a scene of inquiry, the demarcation between
physics and metaphysics seems to hinge on the acceptability of the
methods, techniques and practices used by the community of cosmological
inquirers. Actors seem to be labelling theoretical proposals as metaphysical
when the questions are intelligible to the community and have become
pressing, but are not yet tractable with the accepted means of inquiry.
Thus, intelligible questions are being labelled metaphysical, but may
not be labelled this way indeﬁnitely; if inquirers do ﬁnd a way to make
the questions tractable by means of accepted methods and techniques,
(and if consensus can be reached regarding the legitimacy of such tools),
then the multiverse proposals could become accepted in the domain on
inquiry.

The multiverse scenarios seem to be a primary exemplar of physicists
disagreeing about what constitutes physics and metaphysics in a scene
of inquiry—arising from a scenario where they disagree with how to get
to grips with the questions. The inquirers still pursue inquiry in the hope
that the questions become scientiﬁc at a later period. Thus, in cosmology
during this period what we see is a well-deﬁned scene of response, rather
than of fully-ﬂedged inquiry. This conception of an evolving scene of in-
quiry makes it a rational pursuit for the inquirers to pursue the questions,
even if the means of inquiry are contested.

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343

As Hookway explains,

It can still be rational to inquire into such questions, guided by the
conﬁdent hope that answers will emerge, and by the hope that we will
evaluate those answers in light of evidence. But in that case, our
strategy of inquiry will be primarily focused, not on refuting or
defending particular answers, but on looking for possible answers.
(2008, p. 19)

Consider, for example, the earlier exploration of the possible evolution of the
laws of physics. Hookway notes that revising the answers to questions long-
thought illegitimate is a standard avenue for inquiry in a scene of response,
and having evolving laws is now a potential answer to why questions.

The motivational force rests on a substantial presupposition; there is
a real question here, and we can discover what it is, and when we do,
it will be a question we can handle directly. And the ﬁrst task of
inquiry is to create a situation in which our interrogative expresses
that real question. In order for that to happen, we may have to revise
answers that, we had thought, had been rejected. We may have to
uncover the possibility of answers that, at present, we are not aware
of. We can see the initial interrogative, which expresses no real
question, as setting in motion a course of activities designed to
enable us to ﬁnd such a question. (2008, p. 19)

As noted above by Smolin’s comments regarding the landscape problem
as an answer to explaining “why these laws”, the quest to give an expla-
nation to physical properties of the universe can be traced back all the way
to Leibniz (who, as the history of philosophy attests, failed to realise his
dream):

… the landscape problem as it arises in string theory is symptomatic
of a much older and deeper issue: that the completion of a scientiﬁc
understanding of our universe requires that we not only know what
the laws of nature are, but explain why these are the laws. Thus,
what is at stake is whether Leibniz’s old dream that we can give a
sufﬁcient reason for every physically meaningful property of the
universe can be realized. (Smolin 2013, p. 42)

Leibniz’s “dream” largely disappeared from physics (as natural philosophy)
by the second half of the eighteenth century. Although instances of this
tradition of thought can be found in Peirce and Dirac, as mentioned
earlier, there was no ongoing discussion of such questions in the field of
physics. Of course, alternative ways of getting to grips with the why

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Why These Laws?

questions were proposed, albeit primarily by theologians and metaphy-
sicians. However, in the scene of response of the late twentieth century, a
historical explanation to the “why these laws” question was clearly back on
the table as a distinct possibility.

3.3. Rethinking the 1937 Attack on Cosmythology
As ﬂagged earlier, the 1930s also saw a meta-debate about the legitimate
ways of getting to grips with the cosmos as a whole. Once observational
developments had been coupled with theoretical models of a non-static
universe by the end of the 1920s, the 1930s saw a huge increase in interest
in cosmological questions in physics and mathematics circles. There were a
plethora of competing theories, based on relativistic scenarios, but a great
deal of debate and disagreement in the theoretical community regarding
the legitimate means of undertaking cosmological inquiry. Cosmology was
a young science—new questions had begun to emerge (such as “What is
the large-scale structure of the universe?”; “Is the universe expanding and,
if so, what is the mechanism of the expansion?”, and “Was there a begin-
ning to the universe?”), but were not yet consolidated through a uniﬁed
discipline or a long history of discourse. There was no clear understanding
in the community of what kind of science cosmology should be. Rather,
there were multiple competing views about how cosmological methodology
should proceed.

The debate in the 1930s centred on the demarcation between what con-
stituted legitimate, scientiﬁc cosmology and a metaphysical type of cos-
mythology; a notion which has surprising resonance with Ellis’ concern
regarding cosmological myth. One of the most important alternative cos-
mological theories for this period is the picture developed by Edward
Milne in England (Gale 2002; Lepeltier 2006). From 1932, Milne devel-
oped a theory of kinematic relativity, based on Einstein’s special, but not
the general, theory of relativity. Galaxies in Milne’s model receded propor-
tionally with time. As Kragh points out, Milne’s theory “set the agenda for
a large part of cosmological work” in the 1930s (Kragh 1995). However,
the reason for this turned out to be due not to the physical arguments pre-
sented by Milne, but rather to the epistemological viewpoint that under-
pinned his theoretical approach. Milne’s system explicitly aimed to be
deductive proceeding from axiomatic principles: with a spirit of rationalist
thinking at its core. Milne’s approach was the source of much controversy.
Willem De Sitter, for instance, was concerned when metaphysical assump-
tions entered physics discourse. Speaking in the language of logical posi-
tivists, de Sitter implied a demarcation criterion: “Strictly speaking every
assertion about what has not been observed is outside physics and belongs

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to metaphysics … there is nothing an orthodox physicist abhors more than
metaphysics” (de Sitter 1932, p. 5).12

In 1937, thanks to the provocative proposals by Milne, Eddington and
Dirac, the debate reached a climax (Kragh 1982, Gale and Shanks 1996).
Herbert Dingle13 launched a vitriolic attack on Milne and his metaphys-
ical assumptions. With a title that can only be interpreted as deliberately
vexatious, Dingle attacked cosmythology in his Nature piece “Modern
Aristotelianism”. Employing highly provocative language, Dingle stated
“The phenomenon may be described in broad terms as an idolatry of which
‘The Universe’ is the god … This cosmolatry, as might be expected, came
by metaphysics out of mathematics” (Dingle 1937, p. 786). He likened
metaphysics to a disease that had contaminated certain realms of cosmological
inquiry: “Nor are we dealing with a mere skin disease which time itself will
heal. Such ailments are familiar enough; every age has its delusions and every
cause its traitors. But the danger here is radical. Our leaders themselves are
bemused; so that treachery can pass unnoticed and even think itself ﬁdelity”
(Dingle 1937, p. 786). Dingle argued that it is we who must decide what is
“proper”—to “deduce particular conclusions from a priori general principles
or derive general principles from observations? … the question presented to
us now is whether the foundation of science shall be observation or invention”
(Dingle 1937, p. 785).

12. However, even de Sitter at times showed how vague the boundary between physics
and metaphysics could become. George Gale has identiﬁed that de Sitter accepted the cos-
mological constant, even though it had metaphysical origins. “It has such obvious advan-
tages from many points of view, that it has been generally adopted, even before any
phenomenon has been observed which could be explained by the equations containing
lambda, but not without it” (de Sitter 1931, p. 3). Gale notes that de Sitter was content
to tread close to metaphysical limits if the process undertaken was one guided by extrap-
olation (Gale 2005, pp. 162–63). This is precisely where methodological rhetoric is ex-
posed as inadequate. The way these inquirers actually proceeded in practice was often in
tension with their hyperbolized methodological positions.

13. Herbert Dingle subscribed to an operational philosophical perspective, which he
found present in the general theory of relativity, as well as being a keen follower of Mach’s
positivist empiricism. Dingle followed Rudolf Carnap and other logical positivists in re-
jecting all that is over and above experience. But he went further: still “I make this more
rigorous: only that which is practically observable—that is, only that which would be observ-
able if we were able to use known means of observation to the known limits of their
possibilities—is signiﬁcant” (Dingle 1938, p. 25). He was an empiricist who propounded
a rejection of any a priori methods, and even published a book deﬁning science as organized
common sense (Dingle 1933). This seems an absurd view from a practicing physicist, and
formed part of a positivist manifesto to avoid metaphysical statements at all costs (at least
those that could not be empirically veriﬁed). Indeed, it is difﬁcult to imagine a way of
doing physics in strict adherence to this approach.

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Why These Laws?

The community found itself in a difﬁcult situation after 1937. After the
debate degenerated to scathing assessments of the views in opposing
camps, there was no clear way forward. Neither methodological position
had clear ways of being defended. Few involved in cosmological inquiry
adopted the extreme rationalism of Milne or the extreme empiricism of
Dingle. This slinging match about the very possibility of cosmological
inquiry seemed to halt an already tenuous scene of inquiry, in which
not a great deal of work was being done. The scene effectively collapsed
or unravelled, as the inquirers did not even agree on what questions were
intelligible, let alone which methods made the questions tractable.

In this sense, it may be tempting to equate the scene of response relat-
ing to multiverse discourse identiﬁed at present in cosmological circles
with the methodological debates in the 1930s. However, there is a crucial
difference—today, cosmologists do agree on what questions are intelligible
even if they disagree on how cosmologists should go about answering
them. In 1937, there is no evidence that the inquirers even agreed on what
the intelligible questions were. Unlike today, there was no readily identi-
ﬁable tight-knit community of inquirers who were devoted to what we
would today recognize as cosmology. Even by the late 1940s, there was
a lack of conceptual unity and institutional support, and what little atten-
tion was focused on cosmological questions came from a loosely formed
conglomeration of people working on what Kragh terms cosmo-physics
from an array of different technical backgrounds (Kragh 1996, p. 142).
Thus, the scene in the 1930s could be more accurately described as an
unravelling scene, rather than a scene of response.

4. Conclusions
In tracing the development of multiverse discourse, it appears that the multi-
verse proposals are all possible answers to a set of questions; answers which the
community may deem physical answers in time. The string landscape inter-
pretation of the multiverse has become the most popular for multiverse-
subscribing cosmologists. Through the lens of a historicist deﬁnition of
metaphysical, it appears that the practices of string cosmologists—especially
the innovative theoretical treatment arising from string theory—are seen by
many as the best way of getting to grips with intelligible questions. In a
sense, this is because the string landscape multiverse proposals make the
why questions the most tractable. The extent to which this becomes a widely
accepted method of inquiry, and the contestation surrounding similar
methods in the future, is yet to be seen.

Cosmology has now begun to encroach on territory that has tradition-
ally been reserved for religion and metaphysics; the limits of the possibil-
ities of the space of possible scenes of inquiry have been dramatically

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Perspectives on Science

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extended. Anthropically inspired questions such as “Where do the ﬁne-
tuning values come from?” and “Why this universe in a sea of vast possible
multiverses?” are posed as legitimate issues for scientiﬁc inquiry. Charges
of being too metaphysical are rife, as the ways of making questions trac-
table remain contested in the scene of response. Questions such as “What
happened before the Big Bang?” are now deemed legitimate problems to
be solved using new speculative theoretical models and practices from
string cosmology, and other such fusions between cosmology and theories
of quantum gravity.

Speaking at a string cosmology conference in 2003, science writer
Margaret Wertheim made the following damming, albeit somewhat
jocular assessment of the cosmological scene:14

That string cosmology conference I attended was by far the most
surreal physics event I have been to, a star-studded proceeding
involving some of the most famous names in science… After two
days, I couldn’t decide if the atmosphere was more like a children’s
birthday party or the Mad Hatter’s tea party—in either case,
everyone was high… the attitude among the string cosmologists
seemed to be that anything that wasn’t logically disallowed must be
out there somewhere. Even things that weren’t allowed couldn’t
be ruled out, because you never knew when the laws of nature might
be bent or overruled. This wasn’t student fantasizing in some late
night beer-fuelled frenzy, it was the leaders of theoretical physics
speaking at one of the most prestigious university campuses in the
world. (2012)

Wertheim’s assessment does not seem to be based on what is actually
happening in the day-to-day practice of cosmological inquiry—it is a
general feeling, which arose from attending the conference. However, this
assessment goes some way to highlighting a general excitement, and
perhaps hubris, which has permeated the cosmological community.
Nevertheless, the upshot of this facet of cosmology being a scene of
response is that all possibilities are on the table—the community is
looking for answers in the hope that one of them will be substantiated at a
later date.

We should not forget that there has remained a great deal of accepted,
uncontested cosmological inquiry being practiced since 1980: Cosmolo-
gists working on cosmological questions are still practicing observation,
experimentation, and exploring computer-generated temporal simulations
of the evolution of the universe. The tools of inquiry are widely accepted

14. I thank Ellis’ 2014 paper for alerting me to this excerpt.

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348

Why These Laws?

means of addressing the goals of inquiry. This generally accepted scene of
inquiry is strongly grounded in historical reasoning, but does not bring
untested and nascent physical pictures into the practices of cosmology, un-
less they are deemed valuable elements of the standard cosmological pic-
ture. Inﬂation is an example of a speculative idea that is generally accepted
by cosmologists today, even if they agree that it is somewhat post hoc and
will potentially be replaced in the future. Cosmologists working in this
standard scene of cosmological inquiry may well believe in multiverses,
but their scientiﬁc scepticism stops them from propounding models of
the multiverse before more scrutiny can be turned on the proposals. It is
unclear whether scepticism towards metaphysics constitutes the norm in
cosmology, especially as notions such as metaphysical boundaries have
become so blurred.

There are many examples in recent philosophical and historical litera-
ture on modern physics regarding debates of the legitimacy of speculative
hypotheses in physics and the use of non-empirical rather than empirical
criteria to establish veracity. Richard Dawid’s work examining string the-
ory, and the case where researchers pursue theoretical proposals despite the
lack of empirical testability, attempts to explain “the trust physicists have
in contemporary theories despite the absence of empirical conﬁrmation”
(Dawid 2013, p. 7). His work criticizes sociological accounts for physicists’
commitments to such theories which assume that physicists have some in-
grained tendency to stick together (such as those offered by Smolin 2006;
Woit 2006). Rather, Dawid’s claim is that modern physics has undergone
swift and radical changes which have led to a natural methodological shift
in the way that inquirers assess the veracity of theories. Non-empirical cri-
teria are beginning to play a major role, especially when empirical data is
more difﬁcult to gather (at higher energies and probing deeper than ever
before). The same could be said for cosmology, where inquirers are probing
space-time realms beyond the linear historical narrative of our universe.

There are varying non-empirical argumentative strategies being
deployed in physics today, which inﬂuence the way inquirers assess the
status of theories that are popular, but remain empirically unveriﬁed.
For example, in probing Kaluza-Klein theories, Koray Karaca has recently
argued that “comparatively greater explanatory power, in terms of capacity to
produce testable conclusions regarding natural phenomena, is an important
desideratum in the physicists’ pursuit of the higher dimensional uniﬁcation
of fundamental forces (emphasis in original)” (Karaca 2012, p. 309).
Where empirical methods are contested, it appears that non-empirical ones
emerge as fair game in the scientiﬁc community.

This paper did not set out to give a conceptual analysis of multiverse
proposals, or to give an argument for which empirical or non-empirical

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Perspectives on Science

349

criteria should be drawn upon when arguing for the veracity of such pro-
posals. Rather, the approach was to look historiographically at the new
questions that became intelligible to the cosmological community, and
to trace the resulting multiverse discourse that emerged. Importantly, I
wanted to highlight that the lack of consensus regarding the tools of in-
quiry (the methods, techniques and epistemic practices) is a strong indi-
cator for why there is debate regarding the legitimacy of such questions.
Applying Jardine’s notion of a scene of inquiry to modern cosmology adds
a different meta-perspective on the current debates that prevail, and em-
phasizes the diachronic nature of epistemological and methodological debates
in scientiﬁc circles. Perhaps Dawid’s suggestion of a natural methodological
shift applies to these aspects of cosmology as well—cosmological inquiry has
become a scene of response as a result of the rapid shifts in the available tools
of inquiry available to the practitioners. Answers to previously intractable
questions suddenly appear tantalisingly close.

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