Neuroscience and the Soul
by Nancey Murphy
This
text is found in web pages for The Center for Theology and the Natural Sciences
Note: Words in blue are linked to further information and definitions
Neuroscience & the Soul: Topic Index
In these topics we will
examine the history of conceptions of the human makeup as they arose in ancient
philosophy and religion -- primarily in Christianity, but also with a few notes
about Jewish developments. We also examine new issues that arose in the modern
period, especially as a result of scientific and philosophical developments.
Whereas body-soul dualism had become the majority view by
the end of the middle ages, in the modern period there has been growing
interest in physicalist accounts. Currently, localization
studies by contemporary neuroscientists--that is, finding specific regions or
distributed systems in the brain associated with particular cognitive and
emotional functions--provide some of the most compelling evidence that it is
the brain, rather than a mind or soul, that is responsible for these
capacities. In other words, the current trend in neuroscience is pointing us
towards a reductive physicalist account of the human.
In addition, we will
consider whether a nonreductive physicalist account of the person is in
conflict with essential Christian (and Jewish) teachings. To this end, we will
examine recent developments in biblical studies and consider some of the
implications of a physicalist account of the person for theology.
Other sections will
investigate the philosophical question of reductionism. If mental events are
essentially products of the brain, and if we assume that brain events are
determined by natural laws, then how can we maintain views of human freedom and
responsibility? This is still an open question, but it will be valuable to
consider some of the resources available for addressing the problem.
Finally, we will consider
some of the practical implications of the intellectual changes we have
surveyed.
Introduction
Are human beings composed
of two parts, a material body and a nonmaterial soul, or are human beings
purely physical beings? This question reflects a deep, but often unspoken,
conflict within our culture over views of the very nature of humans. The first
of these views is called dualism (body-soul dualism or mind-body
dualism), and the second is here called physicalism. While this question is an
old one, going back nearly to the beginning of Western intellectual history, it
is becoming more prominent at the present time, due to developments in the
cognitive and neurosciences. While many religious believers hold a dualist
view, these scientific developments make it less and less plausible that we
need the concept of an immaterial mind or soul to account for human capacities
and behavior.
Within the physicalist camp there is another important
distinction between reductionist and nonreductionist views. Thus, we can
distinguish between "reductive physicalism" and "nonreductive
physicalism." The reductive physicalist says that humans are purely
physical beings and thus all of our thoughts, emotions, and experiences are nothing
but brain states. For example, the laws of neurobiology could, in
principle, explain all of human life, including rationality, morality, and even
religion. The nonreductive physicalist, in contrast, says "yes,"
humans are purely physical, but this leads us to recognize that it is our brains
(in our bodies and in social relationships) that enable us to think, to
make moral choices, and even relate to God. Thus, the nonreductive physicalist
position is equally opposed to dualism and to reductive physicalism.
While many conservative
believers worry about conflicts between religion and science, it is more often
argued that religious belief and science are so different they cannot possibly
relate, either positively or negatively. However, this brief survey shows that
concepts of human nature in our culture are the product of both religion and
science, as well as philosophy. Presently, there are conflicting views on the
nature of a person. Thus a dialogue between science and religion can help
provide timely clarification of these issues.
The Person in Greek Thought
One of the most important
sources for Western views of the nature of the human being is ancient Greek
philosophy, especially Plato (427-347 BCE) and Aristotle (384-322 BCE).
According to Plato's dualist view, a human being is a soul
imprisoned temporarily in a body. The soul is immaterial and eternal, and
accounts for human consciousness. Plato believed the soul to have three
`parts': 1.) reason; 2.) the spirited element, which initiates action; 3.) and
the drives and appetites.
Plato's dualist
conception of the person fits well with his dualist conception of reality in
general. Beside this imperfect and corruptible physical world, there is the transcendent realm of the Forms or Ideas,
which is perfect and eternal. According to Plato, the soul's true home is in
the realm of the Forms.
Plato's philosophy had a significant
impact on the development of early Christian thought, largely through the
Neoplatonists who elaborated his ideas and incorporated them into religious
systems. Augustine (354-430 CE), who has been called
the most influential theologian since the Apostle Paul, made great use of Neoplatonist philosophy for treating
theological issues. However, Augustine was compelled to make some modifications
to the Platonic conception of the soul. According to Augustine, a human being
is a rational soul using a mortal and material body, so it is not imprisoned
in the body. Like Plato, Augustine's view of the soul is tri-partite, but there
are some slight differences between the two thinkers. Whereas Plato saw reason
as the highest attribute, Augustine thought that the will was the highest or
dominant aspect. Finally, while the soul is immortal for Augustine, it does not
exist eternally before incarnation, as it does for Plato.
In contrast to Plato, the
Greek philosoher Aristotle thought of the soul not so much as an entity, but
more as a life principle--the aspect of the person that provides the powers or
attributes characteristic of the human being. Therefore, plants and animals
have souls as well—that is, nutritive and sensitive souls.Our souls incorporate
the nutritive and sensitive powers, but also include rational powers. Because
the soul is a principle of the functioning body, it dies with the body
(although Aristotle speculated that perhaps some aspect of rationality survives
death).
Aristotle's conception of
the soul and body also fits well into his general conception of reality. All
material things are comprised of matter and form. The form is an immanent principle that gives things their
essential characteristics and powers. So the soul is but one type of form.
In general, what we see
in Greek philosophical speculation is the recognition that human beings have
some remarkable capabilities all their own (such as doing mathematics and
philosophy) and others that they share with animals (sensation).
The Person in Medieval Thought
Thomas Aquinas (1225-74), the most influential of
Catholic theologians, developed a largely Aristotelian conception of the person, but he
also needed to make some qualifications. While he believed Aristotle's
philosophy helped Christians to appreciate Christian teaching on the resurrection of the body, he still believed
that Christian doctrine required an immortal soul to which the body would be
restored at the general resurrection. Thus, he argued (and not very cogently)
that Aristotle was wrong about the mortality of human souls.
Aquinas’ theoretical
approach to the nature of the soul was to ask, first, in what kinds of
activities do people engage. Then, he identified the kinds of operative powers
needed to explain such actions. Finally, he concluded as to the sort of entity
needed to account for all of these powers. The activities that he recognized
included the biological functions of growth, assimilation of food, and
reproduction. A higher set of activities included sensation, emotional responses
to perceptions, and locomotion. But the highest faculties of all were the
cognitive functions of understanding, judging, and reasoning -- along with the
ability to be attracted to the objects of the understanding (will). This latter
faculty is what accounts for human moral capacities, as well as for the
attraction to God.
We can see that medieval
theology drew on the prior Greek speculations. It did not seem possible to
attribute human powers to the body, so theories were developed about an
additional component of the person to account for them, e.g., the soul.
Further, since living persons can perform the human capabilities and corpses
cannot, the soul was also taken to be the life principle.
The Person in Modern Thought
Over the course of the
modern period (ca 1650-1950) a variety of reasons have emerged for rejecting
the sorts of dualism separating body, mind, and
soul. These reasons encompass theological, philosophical, and scientific
considerations. Theological reasons include: (1) the claim that dualism is not
biblical and that theology ought to reject Greek conceptions in favor of the
original Hebraic conceptions of the Bible; (2) the
related claim that resurrection of the body (rather than
immortality of the soul) was the original Christian account of life after
death; and (3) the claim that dualism has led to an un-Christian depreciation
of the physical creation.
There have always been
philosophical problems connected with the concept of the soul. For example, Plato said that the body could not
affect the soul. If this is so, then how could the senses provide it with
perceptual knowledge? In the modern period, the problems have become acute,
leading most philosophers and many theologians to conclude that a different
account of the nature of the human being is required.
The philosophical reasons
for this change have largely to do with the difficulties (or impossibility) of
explaining how a nonmaterial entity could interact with a material body. In
addition, these problems have been exacerbated by a variety of scientific
developments.
Rene Descartes (1596-1650) is considered the
first modern philosopher, and he has had a tremendous impact on all later
conceptions of the person. Descartes distinguished two basic kinds of created
realities: (1) extended substance, meaning all material things, and (2)
thinking substance, including angels and human minds. (Note in Descartes the
shift in terminology from `souls' to `minds.' These concepts overlapped for
ancient and medieval thinkers, and English-language philosophy has generally
used the term 'mind' rather than 'soul.').
The problem of mind-body
interaction suddenly became more difficult in the Modern period because a
version of atomism came to replace Aristotelian conceptions of matter. In
Aristotle's theory, matter and form were correlative, with form being the
active principle and matter being the passive. So the soul, as one type of
form, was conceived exactly as that which animated, or moved, the body. In the
early modern scientific conception of matter, especially as developed by Isaac Newton, matter was also seen as inert,
or passive. But matter in
These problems have led
most secular philosophers to conclude that we are better off not postulating
minds as entities at all. We may speak, instead, of mental events,
but these are still identical with physical (brain) events, in some way. That
is, we call them mental events as we experience them `within'; physical as we
imagine a neuroscientist looking at the brain from without.
As we have seen, early
modern science's new conception of matter created philosophical problems for
mind-body dualism. Many philosophers have judged these problems to be
insoluble, and this, in turn, has led to a wholesale rejection of the concept
of a substantial mind.
Neuroscience and Thomas Aquinas
Recent science has shown
the fruitfulness of taking the brain to be the seat of all those mental
faculties medieval thinkers, such as Thomas Aquinas, had attributed to the
soul. Therefore, we consider here a variety of results from neuroscience which
make it appear that the various human capacities once attributed to the soul
are better understood as capacities of the human brain.
One sort of research
concerns the localizing of various cognitive and affective functions in
specific regions or distributed systems of the brain. This research began by
studying victims of brain damage, correlating lost faculties with localized
damage discovered during autopsies. With the development of CAT scans
(computerized axial tomography), it has become possible to study correlations
between structural abnormalities and the behavior of people while they are
alive. Further, MRI scans (magnetic resonance
imaging) now provide quite detailed pictures of the brain, more easily
revealing locations of brain damage. And PET scans (positron emission
tomography) allow research correlating localized brain activity with the
performance of specialized cognitive tasks.
These varied techniques
have allowed for the localization of a vast array of cognitive functions. To
show the extent to which current science now studies the capacities once
attributed to the soul, let us consider in more detail the account developed by
Thomas Aquinas of the hierarchically ordered faculties, or powers, of the soul.
Vegetative
Faculties
The `lowest' powers of
the human soul, shared with plants and animals, are the vegetative faculties
of nutrition, growth, and reproduction. All of these processes are now fairly
well understood in biological terms, especially since the discovery of DNA. The brain is significantly
involved here, in that neurochemicals play a large role in appetite and sex
drive; while pituitary hormones control growth.
Sensitive
Faculties
Next higher are the sensitive
faculties, shared with animals but not plants. They include the exterior
senses of sight, hearing, smell, taste, and touch, as well as the four
"interior senses," called sensus communis, phantasia
(imagination), vis aestimativa, and vis memorativa (memory). The sensus
communis is the faculty that distinguishes and collates data from the
exterior senses. An example of this faculty would be associating the bark and
the brownness of the fur with the same dog. The vis aestimativa allows
for apprehensions that go beyond sensory perception. Here, an example would be
apprehending the fact that something is useful or useless; friendly or
unfriendly. This sensitive level of the soul also provides for the power of
locomotion and for lower aspects of appetite -- the ability to be attracted to
sensible objects. This appetitive faculty is further subdivided between a
simple tendency toward or away what is sensed as good or evil, and a more
complex inclination to meet bodily needs or threats with appropriate responses:
attack, avoidance, or acquiescence. Together, these appetitive faculties (all
still at the sensitive level) provide for eleven kinds of emotion: love,
desire, delight, hate, aversion, sorrow, fear, daring, hope, despair, and
anger.
Locomotion is now known
to be controlled by the motor cortex -- running across the top of the
brain -- and by the efferent nervous system.
Great progress has been
made in tracing the processes involved in sensation.
For example, signals are transmitted from two different kinds of
light-sensitive cells in the retina, through a series of processors,
and on to the visual cortex. Smell involves the sending of
signals from six different kinds of receptor cells to the olfactory lobes.
The task Aquinas assigned
to the "interior sense" sensus communis -- the ability to
synthesize input from the various external senses -- is now studied by
neuroscientists as "the binding problem."
The "interior
sense" of memory, identified by Aquinas, has also been researched a great
deal. Long-term memory is now understood to arise from patterns of connections
within the neural network. Short-term memory is believed to be enabled by a
system of "recurrent pathways," such that information is processed,
recycled, and then fed into the process again. The hippocampus is involved in
converting short-term into long-term memory, but how this happens is not yet
known.
One of the most
interesting findings involves the localization of specific sorts of memory.
Paul Churchland presents a map of the brain showing regions involved in
language memory, with different locations being responsible for verb access,
proper name access, common noun access, and color terms.
The parietal lobes are an example, as they are
involved in our memory of faces.
PET scans make it
possible to record localized elevations of neuronal activity. Paul Churchland reports an
experiment in which his wife, Patricia, was asked to perform a task involving
her visual imagination. The activity in her visual cortex was elevated
exactly during the time she was doing the exercise, but not to the same extent
as when she received external visual stimulation. Paul Churchland hypothesizes
that visual imagination involves the systematic stimulation of the visual
cortex "by way of recurrent axonal pathways descending from
elsewhere in the brain."
The vis aestimativa
of Aquinas included the ability to distinguish between the friendly and the unfriendly,
the useful and the useless. One clear instance of this is our ability to read
others' emotions. While there does not seem to be a single location responsible
for this capacity, there are patients whose brain damage has resulted in its
loss. For instance, Churchland describes the patient "Boswell," who
suffers from extensive lesions to the frontal pole of both temporal lobes, and to the underpart of the frontal cortex. One, among many, of his mental
deficits is the inability to perceive emotion. Churchland reports:
I
watched as Boswell was shown a series of dramatic posters advertising sundry
The sensitive appetite
postulated by Aquinas was responsible for emotions such as desire, delight,
sorrow, and despair. Studies of the etiology of mental illnesses involving
inappropriate affect have shown a significant role for neurotransmitters such as serotonin.
Rational
Faculties
The rational faculties
described by Aquinas are distinctively human: passive and active intellect and
will. The will is a higher appetitive faculty whose object is the good. Since
God is ultimate goodness, this faculty is ultimately directed toward God. The
two faculties of the intellect enable abstraction, grasping or comprehending
the abstracted universals, judging, and remembering. Morality is a function of
attraction to the good, combined with rational judgment in reference to what
the good truly consists.
These higher mental
faculties Aquinas attributed to the rational soul are further from being
understood. However, all of them involve language. Even if we do not understand
how these mental faculties depend on brain functioning, we know that
they do because of the close association of linguistic abilities with specific
brain areas, especially Wernicke's area and Broca's area.
Summary
To review, a variety of
results make it appear that the various human capacities Aquinas had attributed
to the soul are better understood as capacities of the human brain. In fact,
these capacities are attributable to specific regions of the brain.
These conclusions are not
uncontroversial. First, there is the argument within neuroscience over
specialization versus globalism. That is, many would argue that each of the
mental capacities listed above is much more a result of global functioning of
the brain, not localized functioning. We need not get into this argument; all
that needs to be pointed out is that the regions cited above are involved
in the specified functions, since all we know is that, if a region is damaged
by illness or injury, a corresponding function is lost. Second, there are still
some philosophers and scientists who maintain a dualist account of the mind and
brain. They point out that however precise science may become in associating
mental functions with the brain, science will never prove it is the brain
performing the functions. It may simply be the case that functions performed by
an independently existing mind, or soul, are just highly correlated with brain
functions.
Thomas Aquinas,
Moral Behavior and Phineas Gage
For Aquinas, the rational
appetitive function was the ground of moral behavior. In his fascinating book, Descartes' Error, Antonio Damasio reports a famous case of brain
damage caused by a metal rod driven through the skull of a railway employee,
named Phineas Gage.
Gage recovered almost entirely from his physical disabilities, except for loss
of sight in one eye. It is surprising, of course, that Gage survived such a
traumatic event at all, but more surprising is the fact that his personality
was completely changed as a result of the accident. Gage's doctor describes how
"the equilibrium or balance, so to speak, between his intellectual faculty
and animal propensities" had been destroyed. The changes became apparent
as soon as the acute phase of brain injury subsided. He was now "fitful,
irreverent, indulging at times in the grossest profanity which was not
previously his custom, manifesting but little deference for his fellows,
impatient of restraint or advice when it conflicts with his desires, at times
perniciously obstinate, yet capricious and vacillating, devising many plans of
future operation, which are no sooner arranged than they are abandoned. . .
." .
These new personality
traits contrasted sharply with the "temperate habits" and
"considerable energy of character" Phineas Gage was known to have
possessed before the accident. Previously, he had "a well balanced mind
and was looked upon by those who knew him as a shrewd, small businessman, very
energetic and persistent in executing all his plans of action." So radical
was the change in him that friends and acquaintances could hardly recognize the
man. They noted sadly that "Gage was no longer Gage." So different a
man was he that his employers had to let him go shortly after he returned to
work. The problem was not lack of physical ability or skill; it was his new
character.
Damasio uses this story
to introduce his research on brain localization. That is, by a careful analysis
of Gage's skull, Damasio has been able to determine exactly which parts of the
brain were destroyed by the iron rod. He infers from this and other similar
cases that specific regions are essential to the sort of practical reasoning
Gage became incapable of performing. To return to Aquinas's language, Gage lost
his ability to be attracted to the Good.
The Person in Hebrew Scriptures
It is now widely agreed
that the predominant understanding of the human being in the Hebrew scriptures
is holistic and nonreductive physicalist. Jewish scholar Neil Gillman
writes:
Biblical
anthropology knows nothing of this dualistic picture of a person which claims
that a human being is a composite of two entities, a material body and a
spiritual or non-material soul. . . .
The
[Hebrew] Bible, in contrast, portrays each human as a single entity, clothed in
clay-like flesh which is animated or vivified by a life-giving spark or impulse
variously called ruah, nefesh, neshamah, or nishmat hayyim. . . .
In
the later tradition, these terms came to be understood as synonymous with the
Greek "soul." But this identification is not in the Bible.
For example, nefesh
first meant neck or throat; by extension it signified a living being. Neshamah
and ruah both mean breath or wind. Since death is the going out of the
breath, it was possible to identify "something that goes out when one
dies" with Plato's soul.
The Person in The New Testament
There is somewhat less agreement
on New Testament conceptions of human nature. Most scholars now agree that the
New Testament generally supports a holistic and nonreductive physicalist account of the person. However,
some argue that the New Testament presupposes dualism, since there are a few passages
appearing to support a doctrine of "the intermediate state." This
intermediate state, it is said, assures Christians that between death and the
general resurrection they survive to await judgment.
Therefore, the person must be "constructed in such a way that at death it
can `come apart,' with the conscious personal part continuing to exist while
the organism disintegrates."
Some of the biblical texts cited to support this are Matthew 10:28; Matthew
27:50; Luke 16:19-31; Luke 23:42-43; John 12:25; 1 Peter. 3:19-20; and
Revelations 6:9-11. Several questions have to be settled in regard to these
texts and their relevance for the "intermediate state." Again, one
question concerns translation. For example, when it is said of Jesus in Mt.
27:50 that he "gave up his spirit," is this to be taken literally, or
as a metaphorical way of saying that he died?
Second, Christians have
had to distinguish between the teaching of Scripture and the assumptions,
concepts, and theories of the time they were used to convey the teachings. In
other words, it is common to speak of God's revelation being accommodated to
the thought-forms of the ancient cultures. An important example is the use of
-- or accommodation to -- ancient cosmology throughout the Old Testament, as
when Isaiah says that God will gather Israel and Judah from "the four
corners of the earth" (Isaiah 11:12). So if it is shown that the
New Testament speaks of an intermediate state -- or otherwise presumes some
sort of dualism -- an important question to raise is whether this is biblical teaching
or merely accommodation to the thought of the times. That is, we have to ask
whether metaphorical language was used to convey theological truths that could
not have been conveyed very well in other thought-forms at the time.
It may be most accurate
to say that the New Testament has no explicit teaching on this issue. Rather,
various New Testament writers assumed one or another conception of the
constitution of the human being in order to teach about other issues concerning
the relation of humans to one another, to the rest of creation, and to God.
The Person in Christian Theology
Critical church history
in the Modern period has recognized significant doctrinal developments. These
developments, largely revolving around semantic difficulties in language
translations, have had a strong bearing on how we have come to our own human
makeup. One important aspect is the recognition of the Hellenization of
Christian thought -- the `translation' of doctrines into the thought-forms and
language of Greek culture. This process, already begun in New Testament times,
accelerated in the Patristic era and continued at least until
the Reformation.
One response to this
recognition was a call to purify theology of its Greek accretions, and to
return to the original Hebraic understanding of Jesus and his
significance. This movement has led to questions over whether body-soul dualism was in fact biblical teaching.
That is, whether both Old and New Testament conceptions of the person have been
distorted by the translation of the original Hebrew and Greek into modern
languages, and the modern interpretation of those scriptures in accordance with
dualistic philosophies.
Nonetheless, Christian
theologians such as Augustine soon adopted the dualist picture
of human nature, and this came to be the most common Christian view until the
present century.
The doctrine of the
intermediate state continues to be a critical issue for some Christians.
Historically, Thomas Aquinas went to great lengths to make
room in his theology for such a doctrine, and it was made official for
Catholicism by the Fifth Lateran Council in 1513. Calvin seems to have
settled the issue for members of the Reformed tradition. His work Psychopannychia
(1542) was written against other reformers who were teaching, either that the
soul simply dies with the death of the body, or that it goes into an
unconscious "sleep" between death and the general resurrection. Despite the fact that psychopannychia
literally means a watchful or sentient "wake" of the soul --
ordinarily used to designate a position such as Calvin's own -- Calvin's
treatise has, instead, been applied to his opponents.
Early psychopannychists
included Luther, Michael Servetus, and Carlstadt,
as well as a variety of lesser-known Radical Reformers, such as Westerburg; some were
banished or put to death for their support of this position.
Finally, is there any
meaning to the question of an intermediate state? If God is not `in time';
perhaps those who are with God after death are therefore not in time, either.
Thus, we may not know what it means to distinguish between immediate
resurrection and resurrection after a period of waiting.
A theological issue,
then, the intermediate state concerns the relation between anthropology and the doctrine of salvation.
Critics of dualism claim that it fosters an overly-narrow conception of
salvation, as merely saving souls for the after-life. They argue that a more
biblical -- and generally more adequate -- account of salvation involves saving
the whole person. Further, this alternative account is as much a this-worldly
concern as a concern for the final state. It can be argued that the conception
of salvation as "getting to heaven" is a Neoplatonic idea, closely
related to Plato's view that the proper abode
of the soul is the realm of the Forms. It is important to emphasize that the
original Christian account of hope for life after death was the expectation
that all would enjoy the resurrection of the body. Wolfhart Pannenberg proposes that a more authentic
Christian view involves the ultimate transformation of the entire cosmos, similar to the transformation
that Jesus' body has already undergone in the Resurrection.
The Person in Jewish Thought
Beginning around the
second century BCE, there were two independent developments
in Jewish thought concerning the afterlife. Prior to that point, the Jewish
tradition had taken death to be the final end of human life. One development
was the expectation of bodily resurrection at the end of time. The other was
the adoption of a dualist account of the person, according
to which the soul survives the death of the body. Neil Gillman says:
In
their original form, the two doctrines of the resurrection of the body and the
immortality of the soul appear independent of each other. One knows nothing of
bodies, the other knows nothing of souls. One ascribes personal identity to the
body; the other, to the soul. One teaches that at the end of time, the body
will be revived. The other insists that the soul is immortal and needs no
revival.
However, Rabbinic Judaism
(from around 200 CE) conflated these traditions, teaching that the soul leaves
the body at death but receives a resurrected body at some later time.
Neil Gillman points out
that while many Jews since the Enlightenment have given up all concepts of
life after death, there is a current movement within Judaism to recapture the doctrine
of bodily resurrection (rather than immortality of the soul). Gillman asks:
[W]hy
stress bodily resurrection rather than immortality of the soul? For many
reasons: Because the notion of immortality tends to deny the reality of death,
of God's power to take my life and to restore it; because the doctrine of
immortality implies that my body is less precious, important, even
"pure," while resurrection affirms that my body is not less God's
creation and is both necessary and good; because the notion of a bodiless soul
runs counter to my experience of myself and of others; because immortality
implies the absorption of my soul into an All-Soul thus denying my
individuality; and because resurrection affirms the significance of society.
Is Behavior Determined, or are we Free?
One powerful reason for
holding to mind-body, or body-soul, dualism in the modern period is that the
major perceived alternative has been a reductive physicalist account, which seems to imply determinism. Therefore, it is important in
theological discussions to distinguish between reductive and nonreductive
versions of physicalism. To see the difference, consider a recent finding by V.S. Ramachandran at the
Now, what further
conclusions are to be drawn from such claims? One commentator says "there
is the quandary whether the [brain] created God or whether God created the
[brain]." Others say
"these studies do not in any way negate the validity of religious
experience or God." A reductionist
response to this research would affirm that religious experience is nothing but
a neurological event in the temporal lobe. However, to see why this is not the
only (or even the most likely) interpretation, consider a parallel case. As
described above, neuroscientists have done a great deal to explain the
processes involved in visual perception. When these neural pathways are mapped
out, it becomes possible to question whether objects in the external world
produce visual images in the brain, or whether the brain produces the
(apparent) objects in the external world.
Just as it is possible to
distinguish between visual perception and visual imagination, similarly it is
possible to make a distinction between authentic religious experience and experiences
that are merely psychological and/or neurological phenomena. Religious
believers have established communal procedures for "testing"
religious experience for authenticity. These tests include consistency with
Scripture or earlier teaching, and whether the experience fits into the life
story of the individual and the community. For example, does it lead to an
increase in the "fruits of the Spirit," such as love, joy, and peace?
The issue of reduction
versus nonreduction can be stated this way. Is it possible to identify mental
states with brain states, while avoiding the implication that mental life is
totally determined by physical laws? If such determinism cannot be avoided,
then human freedom is an illusion. As such, we are deceived about the aspects
of our humanity we hold most dear; religious faith, love, morality, and
intellectual endeavors are merely the outworking of blind laws of physics. The
reductionist says these experiences are nothing but brain states. The
nonreductive physicalist says, instead, that the brain (or the brain in the
body and in social relations) is the means which make these
experiences of God and other humans possible for a physical creature.
Implications Of A Nonreductive Physicalist View
Both Judaism and
Christianity apparently began with a concept of human nature that comes closer
to contemporary nonreductive physicalism than to Platonic dualism. But, both made accommodations to
a prevailing dualistic philosophy, and combined a doctrine of the immortality
of the soul with a doctrine of the resurrection of the body. The pressing
question now, concerns whether to return to those earlier nonreductive
physicalist accounts of human nature, as many Christian theologians have urged
throughout this century.
If a nonreductive
physicalist view of the person is acceptable theologically and biblically, as
well as scientifically and philosophically, a variety of consequences follow in
the fields of ethics, spiritual development, medicine, and psychotherapy.
For example, many
arguments against abortion depend on when the human soul is presumed to appear.
If the soul is present from the moment of conception, then abortion at any
stage of pregnancy is full-scale murder. This argument no longer makes sense
with a nonreductive physicalist account of the person, in which there is no
soul upon which one's humanity depends. Similar sorts of issues arise with
regard to euthanasia. It is certainly true that the
concept of the soul has been valuable for ethical purposes; it needs to be
shown that equally powerful arguments can be constructed using the nonreductive
physicalist account of personhood. For example, Jesus' injunction to care for
the "least of the brethren" (Matthew 25:40) can be applied supremely
to children before they are born, as well as to the elderly at the end of their
life. Notice that in Jesus' parable the emphasis is not on saving the souls of
those who are in distress, but rather, on meeting their bodily needs for food,
water, clothing, and companionship.
Spiritual formation
throughout most of Christian history has presupposed a Platonic conception of
the person. It has often been understood, for instance, that
"mortification of the flesh" is necessary for the flourishing of the
soul. It is likely that a nonreductive physicalist account of the person will
lead to healthier and more effective approaches to spiritual life.
Psychotherapists have
already come to realize the dependence of psychological health on physical
health, such as when a serious illness leads to depression. Equally important
is the less-frequently recognized dependence of physical health on
psychological and spiritual factors. This includes, for example, the role of stress
(a psychological factor) in causing ulcers, high blood pressure, and other
psychosomatic ailments. Spiritual factors, such as resentment resulting from an
inability to forgive others, also play a significant role in affecting one's
physical health. Increasingly, studies are finding that prayer and church
attendance are associated with better health. A nonreductive physicalist
conception of the person can be expected to promote a more integrative practice
in a variety of health-care professions. That is, it will not be possible to
compartmentalize the person and to conclude that physicians treat only physical
illnesses, psychologists only mental illnesses, and pastoral counselors only
spiritual ills.