Is Space Created?

Reflections on akara's Philosophy and Philosophy

of Physics
Jonathan Duquette
K. Ramasubramanian

Philosophy East and West, Volume 60, Number 4, October 2010,

pp. 517-533 (Article)

Published by University of Hawai'i Press

For additional information about this article

http://muse.jhu.edu/journals/pew/summary/v060/60.4.duquette.html

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IS SPACE CREATED? REFLECTIONS ON ŚAN
. KARA’S
PHILOSOPHY AND PHILOSOPHY OF PHYSICS

Jonathan Duquette
Faculty of Theology and Sciences of Religion, University of Montreal
K. Ramasubramanian
Cell for Indian Science and Technology in Sanskrit, Department of Humanities and
Social Sciences, IIT Bombay, Mumbai

Introduction

From Antiquity to the present day, the concept of space has engaged the attention of
philosophers and scientists of every civilization. Space as a subject of philosophical
inquiry appears quite early in Greek philosophy, especially in the works of natural
philosophers such as Philolaus, Plato, and Aristotle.1 For about two thousand years,
Aristotle’s philosophy constituted the framework from which successive generations
of Western philosophers and scientists attempted to reason about space. This view
was shaken, however, with the publication of Newton’s Principia in 1687. In this
monumental work, Newton established the concept of absolute space as an entity
distinct and separate from material bodies, homogeneous, immobile, and causally
inert. Until the advent of Einstein’s theory of relativity (1905–1915), this concept
reigned supreme in classical physics. But with Einstein’s theory, a new way of reflect-
ing upon the notions of space, time, and gravitation was proposed. Not only did the
worldview set forth in this theory give rise to a whole new paradigm in the field of
theoretical physics, beyond what Newton had himself achieved with his theory, but
it also had a strong and vivifying impact on philosophy of science.2 Today, notwith-
standing the various advances in physics per se, philosophers of physics are strug-
gling to come up with an understanding of space that is in agreement with relativity
as well as with the new requirements of quantum physics. As there is no common
theoretical framework yet linking these two theories, there is no final agreement
among physicists and philosophers as to the nature of space.
In India, the concept of space has also been the subject of deep philosophical
inquiry. In ancient Vedic texts, in particular the R.gveda, space is more or less associ-
ated with the idea of a primeval openness in which the world extends and manifests
itself.3 In the later Brāhman.a s, Āran.yaka s, and Upanis.ad s, the emphasis is on the
nature of ākāśa, which emerges as a central concept especially in Upanis.adic cos-
mology. In these texts, ākāśa is endowed with a rich variety of meanings. In some
passages, it is considered one of the five “elements” (mahābhūtas), connected with
hearing and sound; in other places, it is conceived as the space containing all bodies,
or a subtle form of materiality; elsewhere, it is approximated, or even equated, to the
eternal Brahman, the creator and Being underlying the world. In more or less the
same way, this semantic ambiguity is also reflected in the later classical systems of

Philosophy East & West Volume 60, Number 4 October 2010 517–533 517
© 2010 by University of Hawai‘i Press
 Indian philosophy (darśanas). In literature, we find a good deal of discussion and
debate on the concept of ākāśa, involving philosophers from the Nyāya-Vaiśes.ika,
Sām. khya, and Vedānta schools of thought, as well as Buddhist and Jainist philoso-
phers. The topics examined vary from the ontological status of ākāśa to its role in the
transmission of sound, or in the creation and manifestation of the world. Of course,
each school emphasized a particular aspect of ākāśa in consonance with its own
outlook on the world. In the Indian context also, philosophers were facing the diffi-
culty of defining with certainty the nature of space.4
It is the recognition of such a fact, namely that there is no fundamental and defi-
nite answer with regard to space both in modern philosophy of physics and Indian
philosophy, that has led to the present essay. It is indeed interesting, and certainly
enriching, to compare how both these traditions look differently at the concept and
deal with its many facets. In the process, we may also realize that both traditions are
faced with similar questions when trying to evolve a clear picture regarding the
­nature and origin of space. In literature, we find only few comparative studies focus-
ing on this concept from the standpoint of Indian philosophy and physics.5 But as far
as our knowledge goes, there exists no comparative study taking into account both
the standpoint of Indian philosophy and philosophy of physics per se. It is our aim in
this short essay to provide the reader with a few reflections on the subject by taking
resource from both these disciplines. The question tackled here is one that was of
deep interest to classical Indian philosophers and is still debated today: is space cre-
ated? For the sake of simplicity, we have decided to restrict our attention to a particu-
lar adhikaran.a in Śan.kara’s Brahmasūtrabhās.ya (BSB), the viyadadhikaran.a (BSB
II.3.1–7), wherein the origin of ākāśa is questioned and discussed. This short analysis
will be preceded by a brief summary of the views adopted in Vaiśes.ika and Sāṃkhya.
We conclude this essay with a few reflections on the concept of space in the light of
modern philosophy of physics.

The Nature of Ākāśa in Vaiśes.ika and Sāmkhya

Together with Sāmkhya, the school of Vaiśes.ika probably offers the most significant
philosophical explanation of ākāśa as a physical element. Both of these systems pro-
vide an elaborate cosmological model, wherein a list of world constituents is given
together with an explanation of their arrangement. But while Vaiśes.ika divides the
world synchronically in terms of definite and distinct “categories” (padārthas) of real-
ity, Sām
. khya depicts the world in evolutionary terms, as successive stages of the
evolution of prakr.ti, the primary principle of materiality. In Vaiśes.ika, six basic
padārthas are accepted, which are considered to provide a complete inventory of the
kinds of things that one finds in the world: substance (dravya), quality (gun.a), action
(karma), the universal (sāmānya), particularity (viśes.a), and inherence (samavāya).6
Despite its pluralistic outlook on the world, this school also accepts certain structures
of dependence and subordination between categories, such as inherence and con-
junction (sam . yoga). As for Sām
. khya, it traces the whole physical world to a single
source (prakr.ti) rather than to a set of distinct categories. It admits that twenty-three

518 Philosophy East & West

evolutes (vikr.ti) emerged from prakr.ti at the time of creation, in the following order:
non-individualized intellect (buddhi), individuality (aham . kāra), mind (manas), the
five organs of perception (jñānendriyas), the five organs of action (karmendriyas), the
five subtle elements (tanmātras), and the five gross elements (mahābhūtas). Pure con-
sciousness (purus.a), for whose sake evolution takes place, stands apart from the em-
pirical world.
In Vaiśes.ika, the philosophical reasoning about ākāśa is governed by the
substance-quality paradigm. The following list of substances is accepted by Vaiśes.ika
philosophers: the five elements (ākāśa, air, fire, water, earth), direction (diś), time
(kāla), mental organs (manas), and selves (ātman). As substances, each element is
endowed with one specific quality (viśes.agun.a) and connected to a specific sense
organ.7 As in the Upanis.ad s, the correlation between the five elements and the qual-
ities perceived by the sense organs is accepted: ākāśa is associated with sound only;
air with touch only; fire with color and touch; water with taste, color, and touch; and
earth with smell, taste, color, and touch. It is argued by Praśastapāda and his com-
mentators that among the substances only ākāśa can be the bearer of sound.8 No
positive arguments, however, are given that explain how ākāśa, as physical space per
se is qualitatively connected to sound. Thus, the function of ākāśa in this system is
mainly to afford a substantial basis for the phenomena of sound and hearing. It is also
worth noting that Vaiśes.ika introduces in its metaphysics two substances that convey
the idea of space, namely diś and ākāśa. The concept of diś is primarily associated
with the notion of direction, and thus serves as a spatial framework in which things
and phenomena are located with reference to each other. In contrast, ākāśa is some-
thing less structured, without any internal structure or differentiation. It contains all
things without being affected by them in any way.9
An important feature of ākāśa, noteworthy in this context, is its non-atomic and
eternal (nitya) nature. Though it shares with air, fire, et cetera the coordination with a
specific quality (sound) and sense organ (hearing), ākāśa does not consist of any parts
and so cannot form aggregates as other elements do. The other four elements are
indeed composed of indivisible and indestructible atoms (paramān.us). Because they
are composite, they are also non-eternal. Unlike them, ākāśa is taken to be all-
pervasive (vibhu), that is, in contact with all substances of finite size (sarva-mūrta-
dravya-sam . yogitva).10 It is one and the same everywhere. From this property derives
its eternality: having no parts and pervading everything, it is not subject to change
and decay. Space is thus eternal for Vaiśes.ikas, like atoms and Īśvara, the creator of
the world. The all-pervasiveness and eternality of ākāśa are also shared by immate-
rial substances like diś and time. It has also some properties in common with the self,
namely the possession of specific qualities that last only for a single moment and ex-
ist only in certain parts of the substance (e.g., pleasure and pain in the case of the
self, and sound in the case of ākāśa). The fact that ākāśa is envisaged as one of the five
mahābhūtas while being eternal and all-pervasive like immaterial substances is pe-
culiar to the Vaiśes.ika conception of space.
In Sām
. khya, the ontological status of ākāśa is rather different. Though it also ac-
cepts a plurality of existents such as the five elements, atoms, selves, et cetera, like

Jonathan Duquette, K. Ramasubramanian 519

 Vaiśes.ika, Sām. khya admits of only two eternal principles in its metaphysics: prakr.ti
and purus.a. All evolutes of prakr.ti, including ākāśa, have a finite existence and are
ultimately reabsorbed into prakr.ti. Ākāśa is neither created nor eternal: it is mani-
fested through a gradual process of evolution emerging from prakr.ti. Precisely the
five elements emanate from the principle of individuality (aham . kāra), itself emerging
from buddhi, the first evolute of prakr.ti. Among the elements, ākāśa is the first to be
manifest, a characteristic that is also present in the Upanis.ad s and Vedānta. An im-
portant feature of Sām . khya cosmology is its distinction between two phases in the
development of elements: a generic and simple phase in which the elements are not
yet concretized and specified (tanmātras), and a specific phase where these subtle
elements combine together to form the five gross elements (mahābhūtas). In this sys-
tem also, ākāśa has sound (śabda) as its attribute, and so the subtle form of ākāśa is
referred to as śabdatanmātra, the nonspecific essence of sound. In its gross form,
ākāśa manifests specific and perceptible sounds. The distinction between tanmātras
and mahābhūtas is problematic in Sām . khya, however, for there is no definite agree-
ment in the primary texts as to the exact relation between subtle and gross ele-
ments.11 The most common view is that each successive subtle element combines
with the previous one to produce its gross counterpart: the subtle form of ākāśa
(śabdatanmātra) generates the gross element ākāśa; the subtle form of air combines
with śabdatanmātra to produce gross air; et cetera.
We find no indication in Sām . khya of a non-elemental type of ākāśa as in
Vaiśes.ika. Because it is atomic12 and non-eternal, it does not display any r­esemblance
to either prakr.ti or purus.a. Nonetheless, with the later contribution of Vijñānabhiks.u
(sixteenth century), ākāśa comes closer to prakr.ti. It is maintained by him that there
are two kinds of ākāśa: (1) the usual elemental ākāśa (kāryākāśa), non-eternal and
evolved from śabdatanmātra, and (2) a causal one (kāran.ākāśa), non-atomic and
close to prakr.ti.13 The relation between kāran.ākāśa and prakr.ti expresses itself through
space (diś) and time (kāla), which manifest the inherent potentiality for change con-
tained in prakr.ti.14 In his Sām. khyapravacanabhās.ya (II.12), Vijñānabhiks.u maintains
that eternal space and time are of the nature of kāran.ākāśa, and are also all-pervasive.
As to empirical space and time, they are produced from the same ākāśa in terms of
its limiting adjuncts (upādhis).15 If prakr.ti consists in that which brings forth into ex-
istence empirical space and time, we may understand kāran.ākāśa as that very poten-
tiality itself. Hence, phenomena are not taking place in space and time in this view;
empirical space and time are themselves phenomena that depend on a more funda-
mental entity, namely the causal ākāśa.

Śan.kara’s View of Ākāśa: A Discussion in BSB II.3.1–7

As in other schools, the concept of ākāśa has also engaged the attention of Advaitins.
As far as Śan.kara is concerned, we find short references to this concept in some of
his commentaries on the Upanis.ad s, as well as in a few adhikaran.as in the Brahmasū‑
trabhās.ya. The present adhikaran.a, called viyadadhikaran.a (BSB II.3.1–7), is the most
extensive one among them. Its main purport is to elucidate a possible doubt concern-

520 Philosophy East & West

ing the origin of ākāśa. As a matter of fact, we find in the Upanis.ad s two seemingly
contradictory accounts for the creation of elements:
He said, “O good looking one, by what logic can existence verily come out of non-
existence? But surely, O good looking one, in the beginning all this was Existence (sat),
One only, without a second.” That (Existence) says, “I shall become many. I shall be
born.” That created fire. That fire saw, “I shall become many. I shall be born.” That created
water. . . . Those waters saw: “We shall become many, we shall be born excellently.” They
created food [earth]. (Chāndogya Upanis.ad  VI.2.2–4)

From that Brahman indeed, which is this Self, was produced space [ākāśa]. From space
emerged air. From air was born fire. From fire was created water. From water sprang up
earth. (Taittirı̄ya Upanis.ad II.1.1)

In the Chāndogya Upanis.ad (ChU), fire is said to be created first and succeeded by
water and earth, whereas in the Taittirı̄ya Upanis.ad (TU), fire comes in the third posi-
tion while ākāśa and air come before fire. If we agree with the ChU, ākāśa not being
mentioned, we may conclude that it does not originate and is thus eternal. On the
other hand, if we follow the TU, ākāśa must be considered a created element. Thus,
the śruti itself seems to diverge as to the origin of ākāśa. The present adhikaran.a care-
fully analyzes this question and tries to provide a solution that is both in agreement
with logical reasoning and śruti.

The Statements Are Irreconcilable: The Pūrvapaks.ı̄

In the first two sūtras (BSB II.3.1–2) are stated the two different accounts of creation
and their implication as to the origin of ākāśa. The position taken by the pūrvapaks.ı̄
here is that it is impossible to arrive at a final conclusion regarding the creation of
elements because the two theories of creation are fundamentally irreconcilable with
each other. In all evidence, we cannot claim that both fire and ākāśa have the pri-
mary position in the scheme of evolution. Neither can we conceive that they are
created simultaneously, since in the TU fire is said to be created only after ākāśa and
air have been created. Moreover, in the ChU fire is said to be created from sat while
it is created from air in the TU. For all these reasons, both śrutis must be considered
apramān.am, not valid means of knowledge with regard to the creation of elements.

Space Is Eternal: The Siddhānta Ekadeśı̄

The next three sūtras (BSB II.3.3–5) try to maintain the validity of both śrutis by giving
a secondary meaning to the TU and a primary meaning to the ChU, thereby taking
ākāśa as having no origin. The proponent here, referred to as siddhānta ekadeśı̄,
mainly resorts to the Vaiśes.ika theory of causation to defend his point, and also to
certain other statements found in the Upanis.ad s as well as in other scriptures. The
arguments are summarized below.
1. According to Vaiśes.ika, the cause of an effect is of three types: inherent
(samavāyi), non-inherent (asamavāyi), and efficient (nimitta).16 In no case can such
causes account for the creation of ākāśa, the reasons being that: “an inherent cause
of an object is constituted by an abundance of substance of the same class. But for

Jonathan Duquette, K. Ramasubramanian 521

 space [ākāśa] there can be no such abundance of any substance of the same class,
which can constitute its inherent cause; nor is there any conjunction of such sub-
stances which can be accepted as the non-inherent causes from which space can
emerge. And since these two causes are absent, any efficient cause for space, which
functions when these are favourable, becomes a far cry [sic].”17
2. When an entity is created, it is possible to conceive of a distinction before and
after the time of its creation. But this cannot be shown in the case of ākāśa, which can
never be conceived of “as existing without space, interstices, or cavities.”
3. Ākāśa cannot be created, because it is different from other created elements,
such as earth, for it is all-pervasive (vibhu), et cetera.
4. The śruti itself declares the eternality of ākāśa in passages such as “Now the
subtle — it is air and space. It is immortal” (Br.hadāraṇyaka Upanis.ad [BrU] II.3.3);
“Brahman has space as Its body” (TU I.6.2); and “Space is the Self” (TU I.7.1), et
cetera.
In the fifth sūtra we find an interesting objection to this position. If we admit that
ākāśa, being eternal, is on a par with Brahman before creation, how, then, does one
account for the śruti “In the beginning . . . this [universe] was Being alone, one only
without a second” (ChU VI.2.1)? Moreover, if ākāśa is not created, how can we jus-
tify the statement “That by knowing which all that . . . is not known [i.e., all that is
created] becomes known” (ChU VI.1.3)? Here, the siddhānta ekadeśı̄ tries to show
how both these śruti s remain meaningful even if ākāśa is accepted to be present with
Brahman before creation. He first notices that the expression “one only” should be
understood with reference to the absence of effects of Brahman, and not with refer-
ence to ākāśa, which is eternal.18 As for the expression “without a second,” it implies
that there is no other efficient cause for creation than Brahman. But since ākāśa and
Brahman possess the same characteristics, such as all-pervasiveness, partlessness,
and formlessness, it is impossible to perceive them separately. Like milk and water in
a mixture, there is no way to distinguish them separately as two entities. Owing to
this fact, the śruti telling that Brahman is “one only without a second” remains mean-
ingful. For the same reason, the second śruti is respected: by knowing Brahman,
which is non-separate from ākāśa, as water in milk, one comes to know everything
including ākāśa itself.19

Space Is Created: The Paramasiddhānta

In the last two sūtras (BSB II.3.6–7), these arguments are successively refuted by
Śan.kara, the paramasiddhānta, who concludes that ākāśa must be considered as a
created element. In the first of these sūtras, Śan.kara resorts to śruti to defend his posi-
tion. It is maintained that the real import of the statement “That by knowing which all
that . . . is not known becomes known” is that all the things to be known must origi-
nate from Brahman. For example, only those things that are made of clay become
known when clay is known and not the potter, neither the different tools used in the
production of vessels, et cetera. The “all-knowingness” resulting from the knowledge
of Brahman must be understood “in conformity with the logic of the non-difference
of the material and its products.” Thus, if ākāśa is not considered to be a product of
Brahman, it will remain unknown even when Brahman is known. The simile with

522 Philosophy East & West

milk and water is also not tenable. The knowledge of water acquired through the
knowledge of milk is not complete knowledge, for water is known only indirectly
through the knowledge of milk. The water may be there, but there is no way to be
sure. The all-knowingness referred to in the śruti entails that all existents are creations
of Brahman, and so ākāśa must be taken to be created.
In the last sūtra, Śan.kara resorts to logic in order to demonstrate that ākāśa is an
effect, a creation of Brahman. The sūtra — yāvadvikāram . tu vibhāgo lokavat — states
that all products in this world — a pot, a pitcher, a jar, et cetera — are separate entities.
Śan.kara simply extends this reasoning to ākāśa. Since ākāśa can be conceived as
something separate from earth and other elements, it must be taken as a modification
(vikāra) of Brahman. This argument brings much clarity with regard to the way ākāśa,
as material space, was understood by Śan.kara. It is argued here that ākāśa is a prod-
uct since it is separate from other material bodies, such as earth and other elements.
This suggests that ākāśa is conceived as something comprehensible in relation to
other bodies. Conceptually, it cannot be emptied of bodies because its existence is
intimately related to, or dependent on, them. Despite its abstract nature, ākāśa is thus
considered to have a quite reified existence in this school of thought, as is the case
with Vaiśes.ika and Sām . khya. Yet, ākāśa also presents important metaphysical con-
notations in Advaita. Being the first element to emerge from Brahman, it is often ap-
proximated to Brahman or even taken as one of its synonyms (BSB I.1.22, 3.14,
3.41).
Śan.kara then refutes the various arguments raised by the siddhānta ekadeśı̄. He
first argues against the Vaiśes.ika claim that the nature of ākāśa that is by definition
incompatible with any causal dependence. According to the Vaiśes.ikas, any inherent
cause (samavāyi) leading to the production of an effect consists in a variety of materi-
als of the same class (e.g., many cotton threads produce a cotton fabric). It is argued
that we cannot find such a cause in the case of ākāśa. But, it is argued, this rule is not
universally true since, in certain instances, an effect can be produced from materials
belonging to different classes (e.g., a rope made of cotton yarn and cow’s hair).
Moreover, it is possible that an effect can be produced from a cause consisting of a
single material, such as curd produced from milk alone. For these reasons, it is logi-
cal to argue that ākāśa evolved out of Brahman alone, which is at once the efficient
and material cause of the world.
Śan.kara then refutes the claim that since there can be no distinction between the
nature of ākāśa before and after its creation, ākāśa cannot be created. He points out
that in the Vaiśes.ika philosophy itself, sound is considered to be the specific quality
(viśes.agun.a) of ākāśa. Since sound did not exist before creation, the nature of ākāśa
after its creation necessarily differs from that before. This is also justified by the śruti
that declares Brahman to be anākāśam (BrU III.8.8), that is, free from the characteris-
tic of space. In his next argument, Śan.kara dismisses the view that ākāśa has no origin
because it is all-pervasive while other created elements are not. For Advaitins, Brah-
man is the only all-pervasive entity, not because it is in physical contact with all
entities — which is impossible, for it is relationless — but because it is the cause and
essential nature of every entity that exists. In this specific sense, ākāśa cannot be all-
pervasive though it is in a purely spatial sense. Finally, it is argued that ākāśa is im-

Jonathan Duquette, K. Ramasubramanian 523

 permanent because it possesses impermanent qualities, such as sound. For Advaitins,
the relation that exists between substance and quality is that of “identity-in-
difference” (tādātmya). Sound is essentially non-different from its substratum, ākāśa,
and therefore one must accept that ākāśa is as impermanent as sound.

Reflections in the Light of Philosophy of Physics

As one can see from the previous discussion, the origin of space was a matter of
much reflection and debate among Indian philosophers. In consonance with their
own metaphysics, they gave a different ontological status to space, and consequently
also had a different conception of its origin. While the proponents of Vaiśes.ika
thought of space as being eternal, those of Sām . khya and Advaita conceived space to
be a product of evolution, thus having an origin and a finite existence. It is fascinating
to see how, though we now know much more about the physical world than at any
previous time, the same pressing questions seem to inhabit physicists and philoso-
phers today. Is space created or not? Or is it the manifestation of something more
fundamental? Can we even talk about the “creation” of space? Such questions have
been dealt with extensively by physicists and philosophers of physics since the for-
mulation of Einstein’s theory of relativity. Before Einstein, space was but absolute
space, a vast and immutable container in which things and events were taking place.
But with the discovery that space and time are intimately related to each other, as
well as to gravity, a new way of reflecting upon space became necessary.
Another theory that challenged our conception of space is quantum physics.
Quantum theory is primarily used to describe phenomena at the atomic and sub-
atomic levels. In only three decades, starting with Planck’s quantum hypothesis in
1900, this theory completely shattered our understanding of the atomic world. What
it tells us is that the physical reality corresponding to atoms is radically different from
that of classical entities like particles and waves. Why and how this difference came
to exist has been the topic of many debates among the early quantum physicists, and
still is today. In the late 1920s, quantum field theory (QFT) emerged as a result of the
application of quantum theory to classical fields, an endeavor that eventually culmi-
nated in the elaboration of the standard model of particle physics in the early 1970s.
Quantum electrodynamics (QED) is the first quantum field theory, and also the
model for all subsequent ones as it is the most precise of all physical theories that
exist today. As we shall see, the worldview set forth in QFT also brought about a
significant change in our perception of space, especially regarding the nature of the
vacuum. In the last few decades, the major challenge has been to build a theory that
would explain how gravity behaves at the microscopic level, thereby unifying under
a single conceptual framework the four forces of nature. Such a theory that is also
experimentally verifiable is yet to be formulated.

Space as a Manifestation of the Gravitational Field

In the special theory of relativity (SR), the Newtonian notions of absolute space and
time are discarded: space and time become relative to the motion of the observer,

524 Philosophy East & West

and are thus measured differently by observers in different states of motion. This is a
consequence of the “principle of relativity,” which maintains that the laws by which
the state of a physical system undergoes change are the same in every inertial frame
of reference, that is, in uniform translatory motion. In the general theory of relativity
(GR), this principle is extended to all frames of reference including the non-inertial
ones, such as those involving acceleration and gravity. In particular, this theory shows
that the gravitational field is intimately linked to the geometry defined by space and
time, or the spacetime continuum, which in turn is directly related to the matter-
energy content. Einstein’s profound insight was that space and time do not provide
an absolute background to the world, but are dynamic and interdependent with the
rest of the world. As counterintuitive as it seems to be, general relativity’s predictions
have been confirmed with great success in all experiments to date.20
Among the several philosophical problems raised by this theory, there is the old
ontological problem of substance and of the “original stuff” of the world. What is the
fundamental existent thing on which every other existent thing depends? In fact, a
correct interpretation of GR inevitably depends on which of its major entities — 
matter, spacetime, or field — is taken as the basic ontology.21 It also requires that we
understand well the relations between them. In his early years, quite influenced by
the philosopher Ernest Mach, Einstein took massive bodies as the only physical real-
ity, that which determined the gravitational field as well as the geometry of space­
time. But soon he realized that this could not be true as there exist vacuum solutions
to the gravitational field equations; the field was thus ontologically more fundamen-
tal than massive bodies. He also understood that the gravitational field specifies the
very structure of spacetime (i.e., the metric); that is, that the geometry of spacetime is
a manifestation of gravitational interactions. In his final years, Einstein thus took the
gravitational field as the fundamental reality underlying both matter and spacetime.
This particular ontology is referred to in philosophy of physics as a field ontology.22
In SR, the basic ontology is the spacetime continuum for what is privileged in
this theory is the inertial frame of reference, which defines space and time for a cer-
tain observer. But in GR, as far as the field ontology is concerned, there is no such
preference for inertial frames of reference: the massive bodies inherit their spatiotem-
poral properties from the spacetime geometry, which is itself determined by the grav-
itational field. Hence, there exists no real vacuum or empty space in GR because
neither matter nor spacetime can be thought of without an underlying gravitational
field. Thus, Einstein maintains,
There is no such thing as an empty space, i.e., a space without field. Space-time does not
claim existence on its own, but only as a structural quality of the field.23

In empty spacetime, the gravitational field alone constitutes the geometry, or metric,
of spacetime. When massive bodies are present, it is the gravitational field interacting
with matter that plays this role. Einstein’s theory of general relativity is thus primarily
a field theory.
Before Einstein, all objects were understood to dwell somehow in space and
time. After GR, we had to conceive of space and time as relative to and dependent

Jonathan Duquette, K. Ramasubramanian 525

 on a more fundamental substance, namely the gravitational field. What, then, about
the field itself? Does it also depend on a more basic existent, some form of matter, or
another field perhaps? This indeed was the intuition of Einstein, who thought that
both electromagnetic and gravitational fields were manifestations of a more funda-
mental field, the so-called non-symmetrical total field. Until his death in 1955, he
worked on the idea of a unified field theory, yet without any major breakthrough. The
main reason is that electromagnetism is a force that is active at the quantum level,
and that the continuous (differential) geometry on which GR is based is hardly rec-
oncilable with the discrete worldview of quantum physics. Moreover, the equations
of GR break down under extreme conditions, such as the Big Bang of an expanding
universe or black holes, because the gravitational field, the curvature of spacetime,
and the density of matter become infinite. This is the singularity problem.24 Without
a theory that explains how gravity behaves in these conditions, which requires that
we take quantum physics into account, there is no way to define what underlies the
gravitational field. The nature of the “fundamental substance” of the world thus re-
mains nebulous in GR.

The Nature of Empty Space in QFT

The idea of a unified field theory, first intuited by Einstein, came back to the fore in
the mid-1970s through quantum field theory (QFT). QFT originated in the 1920s
from the endeavor to describe the electromagnetic field in accordance with the laws
of quantum physics. Another motivation came from the need to reconcile quantum
physics with the special theory of relativity. Since then, QFT has emerged as the most
powerful language for describing the subatomic constituents of the physical world
and the laws governing them. Also, this theory has contributed significantly to the
development of cosmology and astrophysics, for it allows us to describe the universe
at its very beginnings, at a time when it was extremely small and compact. The basic
idea underlying this theory is that each individual particle is in fact the quantum of a
specific field, called the quantum field: a photon is the quantum of the quantum
electromagnetic field; the electron, of the electron field; and so on. In quantum me-
chanics, each physical system is associated with a certain wavefunction, which pro-
vides a complete description of the system. In QFT, the same wavefunction is taken
as a classical field to be quantized, thus giving rise to the notion of quantum field.
One of the most important features of this theory is that each quantum field is in-
volved in the creation and annihilation of its associated particles, or quanta. Such a
process is not taken into account in quantum mechanics, in which the number of
particles in a given system does not change.
Since a decade or so, QFT has engaged the attention of several philosophers of
physics. Of much concern is the determination of the basic ontology of QFT.25 His-
torically, this problem is closely connected to the interpretation that is given of the
wavefunction in quantum mechanics.26 Briefly, de Broglie and Schrödinger held a
realistic interpretation of the wavefunction, that is, a classical field ontology. The
wavefunction has a physical reality, for it is endowed with energy and momentum,
whereas quantum particles have no individuality of their own. On the other hand,

526 Philosophy East & West

Born was rejecting the reality of the wavefunction, and was in favor of a particle on-
tology. Though a particle shows no identity, the wavefunction cannot itself claim
physical reality; it is only a mathematical tool that gives the probability of finding the
particle in a certain state. Of course, both ontologies present their own difficulties,
and there is still no agreement today as to which ontology should predominate over
the other. In QFT, the situation is different, for the field is involved in the process of
creating and annihilating particles, and thus QFT presents a more substantial argu-
ment. In QFT, indeed, the quanta that emerge from the quantum field are not c­lassical
particles since they do not possess any permanent existence or individuality; also,
the quantum field is not a classical field because it has no continuity. The fundamen-
tal entity in QFT thus corresponds to a new kind of field, more dynamic in nature
because it has the property of generating particles.27
Given this ontology, a major shift in our conception of “empty space” takes
place. Since the whole world is composed of quantum fields interacting with each
other, there is no space in the universe where there is no field.28 More important,
when the number of quanta is equal to zero, that is, when space is empty of material
bodies, the field is still present and its effects can be detected. This is entailed by
Heisenberg’s uncertainty principle (1927), which maintains that the energy of the
quantum field in its vacuum state must always be greater than zero. Recalling that
energy is convertible into matter, the principle thus implies that a certain amount of
energy, in the form of particles, be generated from the vacuum within a time allowed
by the uncertainty principle (∆E∆t ≥ h̄). Such transient particles are called virtual
particles, because they cannot be directly observed with any instruments, though
their presence can be inferred from physical effects like the Lamb shift and the Casi-
mir effect. When two particles interact, there is a whole bunch of virtual particles that
are exchanged between them; it is through such an exchange that interaction (elec-
tromagnetic, etc.) is mediated from a particle to the other (photons, etc.). The vacuum
described by QFT — called the quantum vacuum — is not empty at all, but the locus
of continuous ephemeral fluctuations of matter-energy.
The recognition that the vacuum is somehow substantial is in contradiction with
SR, however. According to this theory, the vacuum is in a state of zero energy, zero
momentum, zero charge, et cetera. If we consider energy and momentum to char­
acterize what we call a substance in both physics and philosophy of physics, the
vacuum cannot be conceived as a substance. On the other hand, the fluctuations in
the vacuum tell us that the vacuum must be something substantial, because it is able
to generate substantial particles. Cao qualifies this problem as “the most profound
ontological dilemma in QFT.”29 The solution he proposed is that the vacuum consists
in a kind of “pre-substance, an underlying substratum having a potential substanti­
ality.” When this pre-substance is excited, it becomes a substance in the form of
particles endowed with energy and momentum. But what is the nature of such “pre-
substance”? What makes it generate substantial particles, and what principle governs
this generation? Such and similar questions have not been convincingly answered up
to now. As in GR, the nature of the “fundamental substance” remains nebulous in
QFT.

Jonathan Duquette, K. Ramasubramanian 527

 Discussion

Unlike the Newtonian concept of absolute and eternal space, the space described in
GR is not absolute but depends on the gravitational field for its existence. According
to this theory, there is no empty space at all because the field always remains present
even when any massive bodies are absent. In QFT, “empty space” is conceived as
some sort of pre-substance, preceding and giving rise to all the constituents of the
world. Here also, the notion of empty space is rejected and replaced by the notion of
an all-pervading and dynamic field, called the quantum field. Yet, because GR and
QFT have not been reconciled up until now, we are unable to address the fundamen-
tal nature of the vacuum, or what underlies the gravitational field. Moreover, the Big
Bang model does not tell us how the laws of nature and constants of the universe got
defined at the beginning of the universe. It is thus impossible, in the present state of
understanding, to pinpoint with precision what underlies the vacuum and its poten-
tial for giving rise to substance, or what sustains the gravitational field of GR. Hence,
in only a few centuries, a major shift has taken place in our comprehension of space.
From the belief that space is something ultimate, beyond which nothing material
seems conceivable, we have moved toward the conception that there is something
beyond space, on which the latter depends for its existence.
Looking at the various discussions that took place among Indian philosophers on
the nature of ākāśa, one feels as though one is in a similar intellectual atmosphere.
That is not to say that the concept of ākāśa, as it unfolded among these philosophers,
is identical with the concept of vacuum in QFT, for instance. If some similarities can
perhaps be noted — for instance, both quantum vacuum and ākāśa are all-pervasive
and the loci for the creation and annihilation of other physical entities — they none-
theless belong to two different traditions, and have evolved in quite different h­istorical
and conceptual environments. What can be noted, however, is that Indian philoso-
phers were also conceiving space in a variety of ways. We find that within each
school, space is endowed with more than one meaning. In Vaiśes.ika, ākāśa is first
taken as a reified element, connected with sound and hearing, and also described on
a par with immaterial and eternal substances. In Sām . khya, ākāśa is considered a
mere product of prakr.ti, also connected with sound, but with the revision made by
Vijñānabhiks.u, it becomes associated with the potential for change in prakr.ti. The
word ākāśa is also used in a variety of senses in Advaita literature. Besides being an
element endowed with sound as its quality, it is also taken as an entity presenting
deep affinities with Brahman, or Ātman. Each school thus presents an understanding
of space that differs considerably from the others, for each school has its own spe-
cific metaphysical and epistemological premises about the world. The richness of
ways in which space has been considered in the Indian tradition is something that
one also finds in contemporary philosophy of physics.
The second point to be noted is that despite the historical gap separating Indian
philosophers from philosophers of physics, both came to a similar conclusion with
reference to the origin of space. We have noticed already that in the last century the
crucial scientific discovery about space has been to realize that it depends on some-

528 Philosophy East & West

thing else for its existence, that it is neither eternal nor absolute. It is remarkable that
both Sām . khya and Advaita arrived at the same conclusion by adopting a completely
different approach. In Sām . khya, indeed, prakr.ti is the fundamental substance out of
which the whole physical world emerges, including ākāśa itself. Similarly, in Advaita,
ākāśa is the first element to emerge from Brahman, the material and efficient cause
of the world. Like every other phenomenal existent, Advaitins define ākāśa to be
mithyā, meaning that it owes its existence to something else, namely Brahman. Of
course, such similarity with modern physics does not mean, as some would like to
say, that Indian philosophers were endowed with a special faculty of discrimination
that allowed them to see what experiments show us today. What it indicates is that
despite adopting different approaches to reality, both Indian philosophers and physi-
cists had a similar insight about the origin of space, namely that it cannot be ultimate
but must depend on something more fundamental for its existence. As Hiriyanna has
noted, this view had no real equivalent in Western thought until quite recent times.30
From the standpoint of the history of ideas, therefore, it is significant that numerous
Indian philosophers adopted this philosophical view centuries ago.

Conclusion

It was noted that both Advaitins and physicists share the notion that space is the prod-
uct of something more fundamental. At the same time, they are both challenged in
describing the nature and origin of what is more fundamental. Somehow, in both
systems, space resides at the boundary of what is known and unknown: beyond, it is
terra incognita. However, the boundary in question has a different shape and con-
notation in both systems. For Advaitins, what lies beyond space is neither a pure
Unknown nor a Nothingness, but That which makes the world evident to the indi-
vidual, that is, the non-dual Brahman, the core Subject. The point here is that Brah-
man is not simply an object of thought that one can perceive and analyze, but is
something to be experienced, or discovered, through contemplation and the deep
understanding that there is “in reality” no duality whatsoever. Rational or logical
thinking ultimately does not lead to this understanding, as it presupposes a duality
between subject and object. In fact, it is such a duality that is the source of one’s
misunderstanding about Brahman, which is pure awareness. The boundary is thus
not between the known and the unknown, understood in a mere logical sense, but
between mithyā and satya, appearance and reality.
As far as physics is concerned, what is required is a “real” distinction between
subject and object, between observer and observed. What lies beyond space is not
pure awareness; rather what is expected is an “object” to be studied, analyzed, and
elucidated and that can be known through good insights and better resources. This is
an epistemological position that differs radically from that of the Advaitins. The
boundary here is not between appearance and reality but between what is unknown
through our present means of investigation and what we actually know about the
physical world. It is revealing to see how both systems envisage differently what is
beyond the boundary, and how they proceed in different ways to acquire this knowl-

Jonathan Duquette, K. Ramasubramanian 529

 edge. Nonetheless, in trying to unravel the Unknown, the same fundamental ques-
tion seems to inhabit ancient philosophers as well as modern physicists: What is it
That by knowing it everything else is known as well? This question, though addressed
by thinkers of all civilizations of all times, still remains alive, approached but never
possessed, pushing seekers from around the world always to refine their understand-
ing of the universe and what is beyond.

Notes

1  –  For a good historical survey of the concept of space from Antiquity to modern
times, the reader may refer to Max Jammer’s Concepts of Space: The History of
Theories of Space in Physics (Cambridge, MA: Harvard University Press, 1954).
2  –  Several books have been published on the subject since then. To mention a
few: H. Reichenbach, The Philosophy of Space and Time (New York: Dover
Publications, 1957); L. Sklar, Space, Time and Spacetime (Berkeley: University
of California Press, 1977); M. Friedman, Foundations of Space-time Theories:
Relativistic Physics and Philosophy of Science (Princeton: Princeton University
Press, 1986); J. Earman, World Enough and Space-time: Absolute versus Rela-
tional Theories of Space and Time (Cambridge, MA: MIT Press, 1992); N. Hug-
gett, Space from Zeno to Einstein (Cambridge, MA: MIT Press, 2002).
3  –  W. Halbfass, On Being and What There Is: Classical Vaiśes.ika and the History
of Indian Ontology (New Delhi: Sri Satguru Publications, 1992), pp. 29–31.
4  –  In the last few decades, a number of Western and Indian scholars have under-
taken serious studies on ākāśa in Indian darśanas. The following are the most
complete papers on the subject: P. C. Divanji, “Brahman-Ākāśa Equation: Its
Origin and Development,” Bharatiya Vidya Bhavan (Bombay) 9 (1948): 148–
173; I. H. Jhaveri, “The Concept of Ākāśa in Indian Philosophy,” Annals of the
Bhandarkar Oriental Research Institute 37 (1956): 300–307; S. C. Chakrabarti,
“Ākāśa,” in B. Bäumer ed., Kalātattvakośa, vol. 3 (New Delhi: Indira Gandhi
National Centre for the Arts, 1996), pp. 103–141; V. Lysenko, “The Vaiśes.ika
Notions of Ākāśa and Diś from the Perspective of Indian Ideas of Space,”
Poznań Studies in the Philosophy of the Sciences and the Humanities 59 (1997):
417–447; W. Halbfass, “Space or Matter? The Concept of Ākāśa in ­Indian
Thought,” in R. Nair ed., Mind, Matter and Mystery: Questions in Science and
­Philosophy (New Delhi: Scientia, 2001).
5  –  We are aware of only one serious study on the subject, which, however, tends
to overlook the differences between Indian philosophy and modern physics:
K. K. Mandal, A Comparative Study of the Concepts of Space and Time in ­Indian
Thought (Varanasi: Chowkhamba Sanskrit Series Office, 1968).
6  –  However, the list of padārthas has been subject to many changes in the history
of Vaiśes.ika. As an example, the classification given by Praśastapāda largely

530 Philosophy East & West

 differs from that previously established by Kan.āda. In contrast with Praśastapāda,
Kan.āda considers non-existence (abhāva) as a padārtha and accepts only the
first seventeen qualities (gun.as) in Praśastapāda’s list of twenty-four qualities.
7  –  In the Padārthadharmasam . graha (p. 58), a substance (dravya) is defined to be
endowed with qualities (gun.as) and not to be located in another substratum
(ato gun.avattvād anāśritatvāc ca dravyam). In Vaiśes.ikasūtra I.1.14, substances
are described as possessing motion and qualities and to be inherent causes
(kriyāvad gun.avat samavāyikāran.am iti dravyalaks.an.am). See Halbfass, On
Being and What There Is, p. 72.
8  –  A good summary of the arguments provided by Nyāya-Vaiśes.ika philosophers
explaining why ākāśa is the only substratum of sound is provided in S. Bhaduri,
Studies in Nyāya-Vaiśes.ika Metaphysics (Poona: Bhandarkar Oriental Research
Institute, 1975).
9  –  For a more detailed discussion on the concepts of diś and ākāśa in Vaiśes.ika,
please refer to Lysenko, “The Vaiśes.ika Notions of Ākāśa and Diś from the Per-
spective of Indian Ideas of Space,” and Halbfass, “Space or Matter? The Con-
cept of Ākāśa in Indian Thought.”
10  –  S. K. Sastri, A Primer of Indian Logic according to Annambhat.t.a’s Tar‑
kasam . graha (Chennai: Kuppuswami Sastri Research Institute, 1998), p. 69.
11  –  Halbfass, “Space or Matter? The Concept of Ākāśa in Indian Thought,” p. 88.
12  –  In Sām
. khya also, each gross element is conceived to be manifold and consists
of finite particles called paramān.u s (Yogasūtrabhās.ya I.40, 45; III.44, 52.). How­
ever, these particles differ from the atoms of Nyāya-Vaiśes.ika, which are taken
as the building blocks of elements, partless, indivisible, and eternal. Though the
atom is similarly defined as the smallest unit of matter in Sām . khya, it differs by
being allowed to have parts. This arises from the conception that the whole is
always inseparably connected with its component parts (as the effect and its
cause) in Sām . khya, and so the substance, however small it is, can never be said
to be partless. See P. Chakravarti, Origin and Development of the Sām . khya
System of Thought (New Delhi: Munshiram Manoharlal Publishers, 1975
[1951]), pp. 251–252; and M. Hiriyanna, Outlines of Indian Philosophy (Delhi:
Motilal Banarsidass Publishers, 2005 [1993]), p. 276.
13  –  Jhaveri, “The Concept of Ākāśa in Indian Philosophy,” pp. 301–302.
14  –  For a detailed discussion on the subject, see K. Bhattacharyya, Studies in Phi-
losophy, vol. 1 (Calcutta: Progressive Publishers, 1956), pp. 169–170.
15  –  The translation of this passage has been found in “Sām . khya: A Dualist Tradition
in Indian Philosophy,” in G. J. Larson and R. S. Bhattacharya eds., Encyclopedia
of Indian Philosophies, vol. 4 (New Delhi: Motilal Banarsidass Publishers, 2006
[1987]), p. 395. Commenting on this passage, Radhakrishnan maintains that
empirical space and time are not the products of kāran.ākāśa but kāran.ākāśa
­itself, particularized by conjuncts (upādhi) in the form of coexistent things in

Jonathan Duquette, K. Ramasubramanian 531

 space and moving bodies in time. See S. Radhakrishnan, Indian Philosophy,
vol. 2 (London: George Allen and Unwin, 1962 [1923]), p. 277.
16  –  In the example of the production of a cloth, the inherent cause (samavāyi) con-
sists in the threads, the non-inherent cause (asamavāyi) in the union (sam
. yoga)
of the threads, and the efficient cause (nimitta) in the weaver.
17  –  Brahma-sūtra-bhā ya of Śrı̄ Śa karācārya, translated by Swami Gambhirananda
(Calcutta: Advaita Ashrama, 2006), pp. 446–447.
18  –  The example cited in this context is that of someone who, going to a potter’s
house on a specific day, sees that there is clay, a potter’s wheel, etc. The next
day, he notices many vessels made of clay and says: “It was all but clay alone
the other day.” By saying that, he means that the products of clay alone were
not present the previous day, and not the potter’s wheel, etc. Similarly, the ex-
pression “one only” refers only to the products or effects of Brahman, and not
to the uncreated ākāśa.
19  –  When one looks at the milk, which is mixed with water, both milk and water
are perceived. By analogy, when one knows Brahman, which is indistinguish-
able from ākāśa, both Brahman and ākāśa are known.
20  –  For example, in 1919 the British astrophysicist Arthur Eddington conducted an
experiment in Africa to confirm that the gravitational field of the sun “bends”
light, an effect predicted by GR. During the experiment, he successfully ob-
served, near the rim of the occluded sun, the light coming from stars located
behind the sun. This would not have been possible if the gravitational field of
the sun did not bend the light from the stars.
21  –  T. Y. Cao provides the following definition of “ontology” in the context of phys-
ical theories: “In contrast with appearances or epiphenomena, and also op-
posed to mere heuristic and conventional devices, ontology as an irreducible
conceptual element in the logical construction of reality is concerned with a
real existence, that is, with an autonomous existence without reference to any-
thing external.” See T. Y. Cao, Conceptual Developments of 20th Century Field
Theories (Cambridge: Cambridge University Press, 1997), p. 10.
22  –  This is, for instance, the position taken by T. Y. Cao in his book Conceptual De-
velopments of 20th Century Field Theories. For more details and references on
this subject, please consult this work, pp. 90–122.
23  –  A. Einstein, “Relativity and the Problem of Space,” in Relativity: The Special and
the General Theory (London: Methuen, 1954), pp. 135–157.
24  –  At the end of the 1960s, a number of theorems were proved that demonstrated
quite convincingly that any model of the universe that satisfies general r­elativity,
given certain reasonable conditions, must have a Big Bang singularity. H­owever,
when quantum mechanics is taken into account, by virtue of the uncertainty
principle, it becomes possible that the singularity may be smeared away. For

532 Philosophy East & West

 instance, in 1983, Hawking and Hartle proposed a model in which there is no
boundary to spacetime, and thus no singularity at the beginning of the universe.
See S. Hawking, “The Edge of Space-Time,” in L. M. Dolling, A. F. Gianelli, and
G. N. Statile eds., The Tests of Time: Readings in the Development of Physical
Theory (Princeton: Princeton University Press, 2003), pp. 677–684.
25  –  The following books deal extensively with ontological aspects of QFT: H. R.
Brown and R. Harre eds., Philosophical Foundations of Quantum Field Theory
(Oxford: Clarendon Press, 1988); S. Y. Auyang, How Is Quantum Field Theory
Possible? (New York: Oxford University Press, 1995); P. Teller, An Interpretive
Introduction to Quantum Field Theory (Princeton: Princeton University Press,
1995); T. Y. Cao, Conceptual Foundations of Quantum Field Theory (Cambridge:
Cambridge University Press, 1999); M. Kuhlmann, H. Lyre, and A. Wayne, eds.,
Ontological Aspects of Quantum Field Theory (Singapore: World Scientific
Publishing, 2002).
26  –  For a general review of the various interpretations of the wavefunction, see M.
Jammer, The Philosophy of Quantum Mechanics (New York: McGraw-Hill,
1974). In this section, we mainly follow Cao, Conceptual Developments of
20th Century Field Theories, pp. 144–152.
27  –  For a more detailed discussion, see Cao, Conceptual Developments of 20th
Century Field Theories, pp. 158–173, and references in endnote 25.
28  –  However, it must be kept in mind that in QFT, quantum fields exist in space and
time. The unification of spacetime with fields, done in GR with reference to the
gravitational field, is not achieved in QFT. We do not discuss here the peculiar
ontological status of spacetime in QFT, but simply present its conception of
empty space, or quantum vacuum.
29  –  Cao, Conceptual Developments of 20th Century Field Theories, p. 176.
30  –  Discussing the metaphysics of Sām. khya, Hiriyanna says: “Even space and time
are represented as aspects of prakr.ti and do not, therefore, exist apart from it as
independent entities. This is a point which is worthy of note, for it shows that
the system does not, like the generality of philosophic doctrines including
much of Western thought till quite recent times, start by positing matter in space
and time, but looks upon the primordial physical entity as including and ex-
plaining them both.” See Hiriyanna, Outlines of Indian Philosophy, pp. 270–
271.

Jonathan Duquette, K. Ramasubramanian 533