Van Huyssteen J.W. (editor) Encyclopedia of Science and Religion

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NATURAL THEOLOGY

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Rationalist or Idealist philosophers seldom

agree with one another, and there seems to be no

way of objectively verifying their claims. However,

this is to be expected from systems that claim to be

based on personal engagement and interpretation.

The difference between traditional natural theol-

ogy and Idealist natural theology is clearly exem-

plified in the writings of German philosopher Im-

manuel Kant (1724–1804). Kant is best known for

his destructive criticism of the traditional argu-

ments for God, but he firmly believed that there is

an underlying reality that is the cause of physical

reality as it appears to our senses. According to

Kant there can be no theoretical knowledge of

such reality in-itself (what he termed “noumenal”

reality), but the mind does provide a priori knowl-

edge of the form and order of sensory appearances

(so knowledge does not depend merely on empir-

ical information). Knowledge depends on the

inner structure of reason, and reason necessarily

postulates God, freedom, and immortality as ideas

in terms of which we must represent ultimate real-

ity to ourselves.

Kant is also, as are most idealists, firmly com-

mitted to science understood as the investigation of

the rational structure of phenomenal experience.

The claim would be that idealism—i.e., the postu-

late that the universe must be thought of as basi-

cally mind-like—is the surest foundation of the nat-

ural sciences, which must presume there is a

rational structure in the natural world. But Idealism

also points out that there are limits to science,

which are reached when it claims to disclose the ul-

timate structure of reality, or to extend its reach

into the realm of the personal or spiritual. That is a

realm into which philosophy can reach, with the

aid of its principles of rational coherence, estab-

lishing a system within which consciousness, value,

and purpose can have an intelligible place. The

crucial question is whether the concepts of value

and purpose have a place in explanations of the

universe. If they do, then an Idealist approach of-

fers a complement to science, which only comes

into conflict with it if and insofar as value and pur-

pose are denied.

Modern appropriations of the design

argument

The failure to establish useful general laws in psy-

chology and sociology, as well as the subjective na-

ture of much of history and economics, suggests

that these areas are not amenable to the scientific

techniques that have been so useful in physics and

chemistry. But the fields of neurophysiology and of

evolutionary psychology contain promises (or

threats) to explain consciousness itself in physical

or evolutionary terms. Consciousness may be a by-

product of past successful survival strategies, and its

present functioning may be incidental to the adap-

tive functions (of discerning prey or avoiding pred-

ators) that it originally possessed. This sort of natu-

ral theology, which argues from consciousness to a

supreme consciousness or Spirit, needs to argue

that consciousness is an irreducible and distinctive

phenomenon beyond the reach of experimental

science. That remains a highly disputed issue.

A third, slightly different approach to natural

theology reverts to the methodology of the sci-

ences, not the Aristotelian method of searching for

essential natures, but the experimental method of

inferring hypotheses from observed evidence. The

most famous example of this approach is found in

the work of eighteenth-century English theologian

William Paley, who inferred from evidences of de-

approach is unlike the Aristotelian approach, since

it does not assume that all substances have final

causes. Rather, Paley’s approach looks at organ-

isms, in particular, as highly organized and efficient

systems for supporting animal and human life, and

argues that it is much more probable that such sys-

tems are designed than that they originated by

chance. If we found a watch, says Paley, we would

surely infer that it had a designer, it is so intricately

organized to a purpose, with all its parts finely bal-

anced and tuned to one another. So we must infer

that the world has a designer, for similar reasons.

This approach was dealt a severe blow by

Charles Darwin’s (1809–1882) theory of evolution

and natural selection, which claims to show how

well-designed organisms can evolve, if not by

chance, than at least by random mutation and nat-

ural adaptation to the environment, in strongly

competitive situations. Given the difficulty Paley

has in accounting for why such strange organisms

as giraffes and ichneuman flies (which lay their

eggs in living caterpillars) exist, mutation and nat-

ural selection seem a better explanation than trying

to figure out why God would design such odd or

unpleasant creatures.

Nevertheless, design proponents argue that a

wise creator may not have specifically designed

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every type of creature that exists. But such a creator

might have designed the general laws of genetic

mutation and environmental selection so that they

would generate sentient rational organisms by a

process that is partly random, yet directed to certain

goals (the existence of rational agency). When one

adds to this the extreme improbability of the laws

of nature giving rise to a universe with life-forms in

it at all, one has an argument to the general elegant

design of the laws of nature and of evolution, if not

to all their particular products. Many of the findings

of physics, which disclose the elegance and inte-

grated simplicity of the fundamental forces of the

physical world, and those of biology, which reveal

the amazingly complex structure of DNA and the

adaptedness of living creatures to their environ-

ment, are strongly suggestive of design.

On the other hand, some argue that any uni-

verse with conscious beings in it would have to be

complex and ordered in just such a way, so it is

hardly surprising that we find such complex order.

The structure is highly improbable, but so is the

existence of any universe at all, so this universe is

no more improbable than any other. In addition, it

may be doubted whether it makes sense to speak

of purpose or direction in evolution, and whether

existence is worthwhile at all. So these probabilis-

tic arguments of design-type natural theology are

far from conclusive.

It seems that the universe, as science shows it

to be, could be the work of an intelligent creator.

But the universe may also just happen to exist as it

does. The inference to a creator is not strictly re-

quired. The arguments of natural theology may

seem to make a creator probable to many people.

They do show the intelligibility and elegance of the

universe, and thus enrich the idea of a creator that

a theist might hold. But they are not overwhelm-

ing, and non-scientific factors concerning the value

and possible purpose of creation will probably

weigh the balance one way or another.

Contemporary assessment

Partly for this reason, many theologians deny that

religious belief depends upon the success of natu-

ral theology. Some, like Swiss theologian Karl

Barth (1886–1996), even argue that the program of

natural theology is based on human arrogance,

and flies in the face of revelation, which is to be

accepted on faith, not because it seems on balance

to be probable. Kant said, “I have had to deny

knowledge, in order to make room for faith” (p.

29). He meant that only when it could be shown

that no speculative knowledge of transcendent re-

ality is possible, so that one could neither affirm

nor deny God by argument, was one free to adopt

faith on practical or moral grounds.

It has come to be widely held in modern the-

ology that faith results either from a commitment

of the will (Søren Kierkegaard [1813–1855]), or

from some basic and nonrational apprehension of

the holy (Friedrich Schleiermacher [1768–1834] and

Rudolf Otto [1869–1937]), or, as according to John

Barth, simply from an act of divine grace, which

has no rational grounds. The problem with such

views is that they prevent anyone from giving a

reason why they should adopt one faith (say the

Christian) rather than another (Islam, perhaps).

Such views are also in danger of isolating religious

belief from scientific belief, so that religion and sci-

ence have no relation to one another. Yet it seems

odd to say that religious belief in a creator God is

not affected by new discoveries about the nature

of the created universe, or that religious beliefs

(such as the belief that God is one rational purpo-

sive creator) have nothing to say about the nature

of such a creation.

Natural theology is often no longer seen as the

task of proving that God exists, or of showing to

any independent observer that God is the most

probable explanation of why the universe is the

way it is. But, it might be said, one should be able

to assemble the best human knowledge in all the

diverse areas of human activity, and show how it

can reasonably be construed, and even shaped into

a more coherent form, by the insights of religion,

which may themselves derive from some distinctive

source in revelation or experience. Natural theol-

ogy will then be the attempt to show how science,

history, morality, and the arts are so related that a

total integrating vision of the place of humanity in

the universe may be formulated. Such a vision will

be religious insofar as it includes reference to an

encompassing reality that is transcendent in power

and value, and that may disclose itself in distinctive

ways. This will not be proof, or even probability,

starting from some neutral, completely shared

ground. It will be an integrating activity of reason,

both provisional in its formulations and constructed

from a standpoint of specific basic postulates and

personal value commitments. Within such a per-

spective, science will be able to make a positive

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contribution to natural theology, and natural theol-

ogy will develop ways of integrating scientific ac-

tivity into a wider worldview. This will be more of

an imaginative art than an inferential or deductive

science. It will not be the intellectual foundation or

prelude for faith, but will involve the construction

of a general worldview within which faith can have

an intelligible place. That is not too far from the

aims of Aristotle, though the distinctions between

natural science, philosophy, and religious belief are

now clearer (but only in some ways) than they

were for him. In this form, natural theology be-

comes the speculative and constructive part of the

post-eighteenth-century discipline of the “philoso-

phy of religion.” As such, it is not confined to one

particular religious tradition, and its exponents may

hold any or no religious beliefs.

However, there are many philosophers of reli-

gion who would hold that systematic construction

is not properly part of philosophy, the function of

which should be primarily analytic and expository.

Therefore, natural theology in all its form remains,

like religion itself, a highly pluralistic and disputed

discipline. It is clear, however, that this is an area

in which science and religion fruitfully interact in

examining the fundamental problem of the ulti-

mate nature of existence.

See also ARISTOTLE; DARWIN, CHARLES; DESIGN

ARGUMENT; EVOLUTIONARY PSYCHOLOGY;

DEALISM; KANT, IMMANUEL; RATIONALISM; THOMAS

AQUINAS

Bibliography

Barrow, John D., and Tipler, Frank J. The Anthropic Cos-

mological Principle. New York: Oxford University

Press, 1986.

Barth, Karl. The Epistle to the Romans (1921), trans. Edwyn

Hoskyns. New York: Oxford University Press, 1933.

Davies, Paul. The Mind of God; The Scientific Basis for a

Rational World. New York: Simon and Schuster, 1992.

Dennett, Daniel C. Darwin’s Dangerous Idea; Evolution

and the Meanings of Life. New York: Touchstone,

1995.

Hume, David. Dialogues Concerning Natural Religion

(1779). Indianapolis, Ind.: Hackett, 1980.

Kant, Immanuel. Critique of Pure Reason (1781), trans.

Norman Kemp Smith. London: Macmillan, 1933.

Kierkegaard, Soren. Concluding Unscientific Postscript to

the Philosophical Fragments (1846), trans. Howard V.

Hong and Edna H. Hong. Princeton, N.J.: Princeton

University Press, 1992.

Otto, Rudolf. The Idea of the Holy (1917), trans. John W.

Harvey. London: Oxford University Press, 1923.

Paley, William. Natural Theology (1802), eds. Henry

Brougham and Charles Bell. London: C. Knight, 1836.

Schleiermacher, Friedrich. On Religion: Speeches to its Cul-

tured Despisers (1799), trans. Richard Crouter. Cam-

bridge, UK: Cambridge University Press, 1988.

Swinburne, Richard. The Existence of God. New York: Ox-

ford University Press, 1979.

Ward, Keith. God, Chance, and Necessity. Oxford:

Oneworld Press, 1996.

Ward, Keith. Religion and Revelation. Oxford: Clarendon

Press, 1996.

Wilson, Edward O. Consilience: The Unity of Knowledge.

New York: Knopf, 1998.

KEITH WARD

NATURE

Nature refers to the source out of which some-

thing has come into being. The word nature is de-

rived from the Latin natura (birth) or nasci (to be

born). A similar meaning is found in the Greek ph-

ysis, which means growth. The concept of nature

holds a variety of meanings, depending on the re-

lation in which it is understood. In a political set-

ting, nature is often seen in contrast to custom,

culture, and law. In religious terms, nature is often

opposed to grace and spirit. Viewed philosophi-

cally, nature can be understood in contrast to his-

tory and freedom. Nature can also be seen as: (1)

the object of scientific observation and enquiry; (2)

a normative notion, such as the question of “natu-

ral” behavior; (3) an essential notion, such as

human “nature”; and (4) a notion concerning evi-

dence, as in the exclamation “naturally!” These dif-

ferent meanings can be taken either as a sign of

the philosophically problematic use of this notion

or its need of specification.

Historical overview

Several of these concepts have their roots in an-

cient Greek philosophy. In pre-Socratic philoso-

phy nature was seen in contrast to relativism. Cul-

tures varied, but nature was considered constant

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and was therefore regarded as ethically normative.

Aristotle, who understood nature in teleological

terms, carried the notion of the normativity even

further. The essence (form) of natural beings car-

ried with it a certain purpose that determined the

good life. The morally good life was believed to be

in accordance with nature, an understanding fur-

ther developed in Stoic philosophy, which argued

for life in accordance with nature.

These concepts of nature had an enduring im-

pact on theological and philosophical thought dur-

ing the Middle Ages. During this period, however,

a contrast between nature and the supernatural was

increasingly endorsed. Nature was distinguished

from the divine. For the Christian philosopher

Thomas Aquinas (c. 1225–1274), however, nature

was not opposed to the divine. Aquinas maintained

an analogy of being (analogia entis) between eter-

nal law (lex aeterna), the constitutive law of being

that is identical to divine reason, and natural law

(lex naturalis), which is understood as the partici-

pation of the rational being in eternal law.

During the sixteenth century, nature could also

be set in contrast to divine will. Consequently, in

the beginning of the seventeenth century, nature

became increasingly understood as morally neu-

tral. As physics became identified with mechanics

during the scientific revolution, nature came to be

understood in mechanistic terms, as something that

could be described with physical laws. This

change in the role of the sciences, and the corre-

sponding change in the understanding of nature,

implied a different relation to nature. Nature be-

came understood as that which was different from

human beings and that which humans, as rational

beings, were to control. The natural sciences

served this purpose as knowledge about nature

was regarded as power over nature.

The philosopher Immanuel Kant (1724–1804)

had an enduring impact on the scientific under-

standing of nature. According to Kant, the different

objects of nature could not be known in them-

selves, but could only be known as appearances

determined by the epistemological categories of

space and time. Consequently, Kant’s transcenden-

tal philosophy implied that in the apprehension of

nature human beings were structuring the very

same nature. Kant became influential for his em-

phasis on the interrelation between nature as an

object and the formative impact of the human ap-

prehension of nature.

Another fundamental turn in the scientific un-

derstanding of nature was the publication of

Charles Darwin’s On the Origin of Species (1859).

According to Darwin’s theory of evolution, new

species originated from other species, and natural

life was formed according to the principles of vari-

ation and natural selection. This view of nature has

often been seen as opposed to a theological un-

derstanding of nature as designed by God. As a

consequence, nature was no longer considered as

good in itself, but as morally ambiguous.

Modern scientific concepts of nature

In a contemporary setting, the diversity of the no-

tions of nature is as varied as in previous epochs,

with a host of holistic, religious, and ecological un-

derstandings in play. Karen Gloy has demonstrated

how an organicist notion of nature has been in use

since the Renaissance. The ecological mode is

present in environmental ethics. The philosopher J.

Baird Callicott argues that nature is to be seen as a

biotic community. Based on evolutionary theory,

nature is regarded as an interrelated, interdepend-

ent, ecological web of life, which raises the ethical

implication that the good is defined as that which

furthers the stability of the biotic community. Jür-

gen Moltmann endorses a theological understand-

ing of evolution in which evolutionary theory is

not contrary to the doctrine of creation. Like Calli-

cott, Moltmann argues that the ecological commu-

nity of life serves as the basis of the moral demand

to preserve nature. Furthermore, both Callicott and

Moltmann endorse the connection between a ho-

listic and normative notion of nature.

In other theories, nature is seen as self-

organizing. Niels Henrik Gregersen views nature in

the light of autopoietic systems theory. It is argued

that the Christian theology of creation is not con-

trary to an understanding of nature as self-produc-

tive. God’s self-consistency and self-relativization in

exchange with nature is endorsed. God not only

sustains nature but is also seen as a structuring

cause. Michael Welker challenges the traditional

concept of creation. Often creation is understood as

a unique act of bringing into existence, but Welker

argues that God is not simply active but also reac-

tive in the creation of the world. The act of creation

is an interaction between God and the activity and

productivity of nature. Both Gregersen and Welker

argue for the self-productivity of nature.

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Nature continues to be a fundamental reli-

gious, philosophical, and scientific concept. The

variety of meanings and aspects to this notion is

perhaps one source of its continuing appeal to var-

ious discourses of enquiry.

See also AUTOPOIESIS; KANT, IMMANUEL

Bibliography

Callicott, J. Baird. In Defense of the Land Ethic. Essays in

Environmental Philosophy. Albany: State University of

New York Press, 1989.

Darwin, Charles. On the Origin of Species (1859). New

York: Bantam, 1999.

Gloy, Karen. Das Verständnis der Natur. I Die Geschichte

des wissenschaftlichen Denkens. Munich, Germany:

Verlag C. H. Beck, 1995.

Gloy, Karen. Das Verständnis der Natur. II Die Geschichte

des ganzheitlichen Denkens. Munich, Germany: Ver-

lag C. H. Beck, 1996.

Gregersen, Niels Henrik. “The Idea of Creation and the

Theory of Autopoietic Processes.” Zygon 33, no. 3

(1998): 333–367.

Moltmann, Jürgen. God in Creation: A New Theology of

Creation and the Spirit of God, trans. Margaret Kohl.

San Francisco: Harper, 1985.

Soper, Kate. What is Nature? Culture, Politics and the

Non-Human. Oxford: Blackwell, 1995.

Welker, Michael. “What is Creation?: Reading Genesis 1

and 2.” Theology Today 48, no. 1 (1991): 56–71.

ULRIK B. NISSEN

NATURE VERSUS NURTURE

Nature and culture are classical opposites, or com-

plements. By nature we are “born that way”; by

nurture we learn to become civilized.

In one sense, “nature” refers to everything gen-

erated or produced. Etymologically, the Latin

natura is the source from which all springs forth.

For metaphysical naturalists, perhaps also for

methodological scientists, nature is all that there is,

without contrast class. Nothing non-natural or su-

pernatural exists. Humans evolved within nature

and break no natural laws. Another view holds that

a straightforward contrast class for nature is cul-

ture, which nurtures humans into an inherited lin-

guistic and symbolic system, a worldview, by

which they communicate, perpetuate, and develop

knowledge. This cultural genius makes possible

the deliberate and cumulative, and therefore the

extensive, rebuilding of nature. Humans reshape

their environments, rather than being themselves

morphologically and genetically reshaped to fit

their changing environments. Humans come into

the world by nature unfinished and become what

they become by nurture.

Cultural education

Etymologically, “culture” is related to “cultivate,”

while “nurture” is related to “nurse” and “nourish,”

with overtones of rearing and training. Religious

persons find their traditions vital in such nurture,

and absent from nature. “Train up a child in the

way in which he should go” (Prov. 22:6).

Such cultural education requires second-order

intentionality. First-order intentionality is intent to

change the behavior of another actor, and this is

widespread in the animal world. Second-order in-

tentionality is intent to change the mind (and usu-

ally also the behavior) of another animal; this

seems absent among animals (or almost so). Al-

though animals are variously socialized, they are

not in this sense nurtured. Without some concept

of teaching, of ideas moving from mind to mind,

from parent to child, from teacher to pupil, a cu-

mulative transmissible culture is impossible.

Though language comes naturally to humans, what

is learned has been culturally transmitted, using a

specific language; the content learned during

childhood education is that of an acquired, non-

genetic culture.

Religious persons detect a supernature imma-

nent in or transcendent to nature, perhaps even

more in human culture. They find that neither na-

ture nor culture is self-explanatory; both point to

deeper forces, to a divine presence.

In contemporary biological and human sci-

ences (anthropology, psychology, sociology), as

well as in philosophy, there is much effort to nat-

uralize culture, with equal amounts of resistance to

such reduction (if that is what it is). Sociobiologists

hold that genetic constraints are the principal de-

terminants of culture; only those people and cul-

tures survive that can place genes in the next gen-

eration. Evolutionary psychologists discover that

humans have an “adapted mind,” a modular mind

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with multiple survival subroutines more or less in-

stinctive—in contrast to the highly rational tabula

rasa (empty, pliable mind) once favored by hu-

manist philosophers. Philosophical pragmatists

may agree that the mind is mostly a survival tool,

even in its cultural education.

Culture remains a major determinant, never-

theless. Information in nature travels intergenera-

tionally on genes; information in culture travels

neurally as persons are educated into transmissible

cultures. The determinants of animal and plant be-

havior are never anthropological, political, eco-

nomic, technological, scientific, philosophical, eth-

ical, or religious. Animal imprinting and limited

transmitting of acquired information notwithstand-

ing, humans gain a deliberated modification of na-

ture that separates humans in their cultures from

nature, increasingly so in high-technology cultures.

Since decoding the human genome, completed in

2001, people stand at the threshold of rebuilding

even their own genetic nature.

Nature-culture dualism

Humans have a dual inheritance system, nature

and nurture. The intellectual and social heritage of

past generations, lived out in the present, re-

formed and transmitted to the next generation, is

regularly decisive. Cultures, especially modern

ones, change rapidly in a few decades; the human

genome hardly changes in thousands of years.

Slow-paced genes are difficult to couple with fast-

paced cultures.

A relatively pliable, educable mind is as great

an adaptive advantage as is a mind with instinctive

routines. The mind is so complex that the number

of neurons and their possible connections (with

resulting myriads of cultural options) far exceeds

the number of genes coding the neural system; so

it is impossible for the genes to specify all these

connections. Human genes have generated an or-

ganism whose behavior results from an education

beyond direct genetic control. As more knowledge

is loaded into the tradition (fire building, agricul-

ture, writing, weaponry, industrial processes, ethi-

cal codes, electronic technology, legal history) the

genome selected will be one maximally instructible

by the increasingly knowledgeable tradition. This

will require a flexible intellect, able to accommo-

date continual learning speedily, adopting behav-

iors that are functional in whatever cultures hu-

mans find themselves. This is consistent with the

unusually long period of child rearing in nuclear

families with unusually large-brained babies, found

in human evolutionary history and uncharacteristic

of any other species.

Critics complain that nature-culture dualism is

an undesirable Cartesian legacy (perhaps also a

Christian or Greek one). The “versus” in the title of

this entry frames the connections wrongly. Nature

is the milieu of culture, and supposing our cultures

to be in exodus from nature is at the root of our

environmental crisis. Culture remains tethered to

the biosystem, and the options within built envi-

ronments, however expanded, provide no release

from nature. An ecology always lies in the back-

ground of culture; no nurture is adequate that for-

gets these connections.

Perhaps cultural nurturing reinforces natural

genetic dispositions for some practices (such as in-

cest avoidance), but not for others (learning nu-

clear physics). Whether adults have enzymes for

digesting fresh milk will determine their pastoral

practices. But the differences between the Druids

of ancient Britain and the Maoists in modern China

are nongenetic and to be sought in the radically

differentiating historical courses peculiar to these

cultures—even though Druids and Chinese have a

biological nature largely held in common and de-

spite differences in skin color or in blood groups.

Humans are only part of the world in biologi-

cal, evolutionary, and ecological senses—their na-

ture; but Homo sapiens is the only part of the

world free to orient itself with a view of the whole,

to seek wisdom about who they are and where

they are, and to develop their lives on Earth by

means of culture. Such cumulative, ongoing nur-

ture determines outcomes in the uniquely histori-

cal behavior of humans, making the critical differ-

ence, while human universals, biological,

psychological, or social, which are a legacy of na-

ture, have limited explanatory power.

See also DNA; GENETIC DETERMINISM; GENETICS

Bibliography

Barkow, Jerome H; Cosmides, Leda; and Tooby, John,

eds. The Adapted Mind: Evolutionary Psychology and

the Generation of Culture. New York: Oxford Univer-

sity Press, 1992.

Bock, Kenneth. Human Nature and History: A Response

to Sociobiology. New York: Columbia University

Press, 1980.

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Cavalli-Sforza, Luigi L., and Feldman, Marcus W. Cultural

Transmission and Evolution: A Quantitative Approach.

Princeton, N.J.: Princeton University Press, 1981.

Durham, William H. Coevolution: Genes, Culture, and

Human Diversity. Stanford, Calif.: Stanford University

Press, 1991.

Plumwood, Val. Environmental Culture. New York: Rout-

ledge, 2002.

Rolston, Holmes, III. “Culture: Genes and the Genesis of

Human Culture.” In Genes, Genesis and God: Values

and their Origins in Natural and Human History.

New York: Cambridge University Press, 1999.

Wilson, Edward O. On Human Nature. Cambridge, Mass.:

Harvard University Press, 1988.

HOLMES ROLSTON, III

NEO-DARWINISM

Neo-Darwinism, the modern version of Charles

Darwin’s theory of evolution by natural selection,

incorporates the laws of Mendelian genetics and

emphasizes the role of natural selection as the main

force of evolutionary change. The term neo-Dar-

winism was first used in the 1880s by August Weis-

mann, a German naturalist, who incorporated his

theory of the germ plasm into Darwin’s theory of

evolution by natural selection. Weismann advo-

cated the theory that the body is divided into germ

cells, which can transmit hereditary information,

and somatic cells, which cannot. Weismann thereby

added a mechanism of heredity different from Jean

Baptiste de Lamarck’s inheritance of acquired char-

acteristics, which prepared the ground for the re-

discovery of Gregor Mendel’s laws of inheritance

by Erich von Tschermak, Hugo deVries, Carl Cor-

rens, and William Bateson around 1900.

The rediscovery of Mendel’s work led first to a

critique of Darwin’s theory of evolution, as the

new school of Mendelians (Bateson, deVries, and

others) believed that differences in discrete traits

among individuals were too big to fit into Darwin’s

theory of gradual change of phenotypes. Another

school of thought that developed during the first

two decades of the twentieth century involved the

biometricians (Karl Pearson, Francis Galton, and

others), who opposed the view of the Mendelians

and studied small differences in so-called quantita-

tive traits (e.g., body size), using statistical methods

and assuming that most genes had only minor

effects on traits. The controversy between

Mendelians and biometricians was resolved by R.

A. Fisher in 1918 when he showed that Mendelian

inheritance and gradual changes in phenotypes

were not incompatible. In the following two

decades Fisher, J. S. B. Haldane, and Sewall Wright

used mathematical tools to elaborate on this com-

bination of the laws of genetics and Darwin’s the-

ory of evolution, thereby developing the modern

synthesis and the new field of population genetics.

Modern synthesis, which has since been called

the “neo-Darwinian theory of evolution,” was soon

accepted and integrated into different biological

disciplines, including population genetics, compar-

ative anatomy, zoology, biogeography, palaeontol-

ogy, and systematics. Influential books, such as Ge-

netics and the Origin of Species (1937) by

Russian-born American experimental biologist

Theodosius Dobzhansky, The Modern Synthesis

(1942) by British biologist Julian S. Huxley, Sys-

tematics and the Origin of Species (1942) by Ger-

man-born American zoologist Ernst Mayr, and

Tempo and Mode of Evolution (1944) by American

palaeontologist George Gaylord Simpson are ex-

amples of this development and of the neo-

Darwinian theory of evolution as having become

broadly accepted among contemporary biologists.

Evolution from a neo-Darwinian viewpoint is

defined as genetic change in populations through

time (descent with change), with modern organ-

isms being descendents of earlier, different organ-

isms. In addition to natural selection, mutation,

random genetic drift (i.e., random fluctuations in

gene frequencies due to chance), and gene flow

are considered important factors of evolutionary

change with mutation being the ultimate source of

genetic variation.

See also DARWIN, CHARLES; EVOLUTION; GENETICS;

AMARCKISM; MENDEL, GREGOR

Bibliography

Dobzhansky, Theodosius. Genetics and the Origin of

Species. New York: Columbia University Press, 1937.

Huxley, Julian S. Evolution: The Modern Synthesis. Lon-

don: G. Allen and Unwin, 1942.

Mayr, Ernst. Systematics and the Origin of Species. New

York: Columbia University Press, 1942.

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Simpson, George Gaylor. Tempo and Mode of Evolution.

New York: Columbia University Press, 1944.

VOLKER LOESCHCKE

NEO-ORTHODOX THEOLOGY

See CHRISTIANITY, REFORMED, ISSUES IN SCIENCE AND

RELIGION

NEURAL DARWINISM

Neural Darwinism is a theory of brain develop-

ment laid out in 1987 by neurobiologist Gerald

Edelman (b. 1929). According to this theory, selec-

tive forces, both of development and experience,

operate on neuronal groups rather than on single

neurons. Movement-sensation categories are con-

tinually re-categorized, producing maps that inter-

act in ensemble, and establish the coherent tem-

poral patterns of a unified notion of brain. This is

an empirically viable neurobiological theory of in-

dividuality, about how a person’s unique memo-

ries, perspectives, and autonomous mental life

evolves. The role it may play in a wider theory of

consciousness as a kind of “remembered present”

is as yet unclear, despite its advantages over other

connectionist or neural network models.

See also NEUROPHYSIOLOGY; NEUROPSYCHOLOGY;

EUROSCIENCES

Bibliography

Edelman, Gerald M. Bright Air, Brilliant Fire: On the Mat-

ter of the Mind. New York: Basic Books, 1992.

JOHN A. TESKE

NEUROPHYSIOLOGY

Neurophysiology is the area of neuroscience that

studies the functioning of nerve cells, with a pri-

mary focus on their information coding, transmis-

sion, and storage capacities. Neurophysiology in-

cludes study of the electrical properties of the

nerve cell membrane, the generation of action po-

tentials that carry information, and the communi-

cation of this information between cells over the

synaptic space. One important question occupying

a great deal of time and effort is the nature of

changes in synaptic efficiency that occur with

learning. The functioning of groups of neurons, in-

cluding reflex loops and assemblages of neurons

into neural networks, is also widely studied.

See also MIND-BODY INTERACTION; NEUROSCIENCES

WARREN S. BROWN

NEUROPSYCHOLOGY

Neuropsychology is the area of neuroscience that

studies relationships between brain function and

behavior, with a central focus on human brain-

behavior relationships. Neuropsychological re-

search attempts to map the brain structures and

functions that are critical for particular mental/cog-

nitive, emotional, and behavioral capacities. Clini-

cal neuropsychology involves assessment of per-

sons with diseased or damaged brains to evaluate

whether the patient’s cognitive, behavioral, or

emotional functioning has been compromised. De-

velopmental neuropsychology is the study of the

relationship between the development of brain

structure and function, and the emergence of cog-

nitive abilities. Finally, neuropsychological rehabil-

itation attempts to ameliorate the negative impact

of brain damage.

See also MIND-BRAIN INTERACTION; NEUROSCIENCES

WARREN S. BROWN

NEUROSCIENCES

Neuroscience is the scientific study of the nervous

system and its function. Since the nervous system

can be studied at many levels—from the molecular

structure of nerve cell membranes to the whole-

brain functions involved in the highest of human

mental activity—neuroscience is a multidisciplinary

field. Neuroscientists might study the nervous sys-

tems of simple creatures (e.g., sea slugs), more

complex animals (e.g., rats, cats, and monkeys), or

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human beings. At meetings of the Society for Neu-

roscience one finds over ten thousand scientists

representing a wide variety of fields such as mi-

crobiology, histology, neuroanatomy, neurophysi-

ology, physiological psychology, developmental

psychology, neuropsychology, neuroradiology,

neurology, psychiatry, and cognitive science.

The various domains of research in neuro-

science might be grouped into the following topic

areas:

• Cellular and molecular neurophysiology;

• Developmental neuroscience;

• Sensory and motor neuroscience;

• Regulatory neuroscience;

• Behavioral and cognitive neuroscience; and

• Clinical neuroscience.

After a brief review of the history of neuro-

science, each of these areas will be described. This

will be followed by a summary of current research

on religious experience and brain function. Finally,

the philosophical presuppositions of neuroscience

will be briefly summarized.

The history of neuroscience

The ancient-to-modern history of neuroscience in-

volved resolution of four major issues. The first

issue was whether mental activity and control of

behavior emanated from the brain or the heart.

Next, there was the issue of whether the critical

parts were the ventricles and cerebral fluids (the

pneumatic theory) or the brain tissue itself. When

it became clear that the various structures of the

brain were the organs of thought and behavior,

there was a controversy over localization of these

functions in specific brain areas versus a holistic

view of brain function. Finally, with respect to neu-

ral tissue, research in the late nineteenth and early

twentieth centuries established that independent

neural cells (neurons) are the basic functional units

of the nervous system.

The work of the ancient Greek physician Hip-

pocrates (460–375

B.C.E.) on epilepsy is among the

most important ancient contributions to neuro-

science. Hippocrates denied that epilepsy was a

divine or sacred manifestation, arguing instead that

it was a disease of the brain. He considered the

brain to be the seat of all mental experience. The

alternative view was advanced by Aristotle

(384–322

B.C.E.), who is considered by many to be

the greatest biologist of antiquity. Aristotle taught

that the heart was the center of sensation, move-

ment, and intelligence. Around the same time, im-

portant contributions were also being made in

Alexandria. Herophilos and Erasistratos (third cen-

tury

B.C.E.) distinguished various brain structures,

provided the first description of the ventricles, and

associated intelligence with the greater number of

convolutions in the cortex of the brain.

The progress of these ancient neuroscientists

was extended in the work of Galen (129–199

C.E.)

in Rome. Galen contributed important studies of

the cranial nerves and the spinal cord. Using tran-

sections of the spinal cord, he determined that the

spinal cord was an extension of the brain and the

conduit of sensory and motor information. How-

ever, Galen’s theory of brain function was pneu-

matic, focusing on the ventricles rather than brain

tissue. During the medieval period, the theories of

Galen became dogma and were transmitted with-

out much modification into the Renaissance.

New advances in neuroscience during the Re-

naissance were triggered by a rediscovery of the

work of the ancients, including descriptions of the

original work of Galen. Progress during the Renais-

sance was made by Andreas Vesalius (1514–1564),

who discredited the ventricular theory; René

Descartes (1596–1650), who had the idea of the

body as a machine and developed the concept of a

reflex; and Thomas Willis (1612–1675), an anatomist

who provided the most complete description to that

date of the anatomy of the brain (and whose book

was famously illustrated by Christopher Wren).

The progress in neuroscience achieved in the

Renaissance was accelerated during the Enlighten-

ment. Important progress during this period was

made by Franz Joseph Gall (1758–1828) and Jo-

hann Casper Spurzheim (1776–1832). These inves-

tigators proposed that the gyri of the cortex were

composed of cells that connected to the brain stem

and spinal cord, and, therefore, the cortex could

control movement via its connections to the spinal

cord. The most famous aspect of the work of Gall

and Spurzheim was phrenology, the study of the

relationship between skull surface features and

mental faculties. What is important about this work

is that skull features were thought to reveal the

size of underlying cortical gyri, thus phrenology

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was the first extensive theory of the cortical local-

ization of cognitive functions.

Pierre Flourens (1794–1867) is credited with

demolishing phrenology, while advocating the

idea that all intellectual functions are coextensive

within the cortex (a holist view). Flourens devel-

oped the research strategy of removing or lesion-

ing parts of the brains of animals and observing

consequent changes in their behavior. However,

the localizationist view was kept alive by the work

of Paul Broca (1796–1881) and Carl Wernicke

(1848–1904), who identified the expressive and re-

ceptive language areas of the left cerebral hemi-

sphere (respectively). Based on the discovery of

the bioelectric nature of the function of muscles

by Luigi Galvani (1737–1798), Gustav Theodor

Fritsch (1838–1929) and Eduard Hitzig (1838–

1907) demonstrated that the brain was electrically

excitable, and that electrically stimulating different

cortical locations produced different behavioral

effects.

During the nineteenth and early twentieth cen-

turies advances were also being made in under-

standing the microstructure and microfunction of

the nervous system. Due to the availability of im-

proved microscopes, Theodore Schwann

(1810–1882) was able to discover and describe the

fact that the organs and tissues of animals, includ-

ing the brain, were made up of many individual

cells. However, Schwann believed that the brain,

unlike other organs, was made up of cells that

were not separated by membranes, but rather were

a continuously interconnected network. It took a

lifetime of painstaking work by the Spanish neu-

roanatomist Santiago Ramón y Cajal (1852–1934) to

demonstrate that each neuron is an independent

and discontinuous cell. Charles Scott Sherrington

(1857–1952) was the first to describe the synapse,

the point of communication between neurons. The

microstructure of the nervous system became dy-

namic with the description of the action potential

by A.L. Hodgkin (1914–1998) and A. F. Huxley

(1917– ). Finally, the hypothesis (since substanti-

ated) that the site of learning within the nervous

system is the synapse was advanced in 1949 by

Donald O. Hebb (1904–1985).

Cellular and molecular neurophysiology

Cellular and molecular neurophysiology is the

study of the molecular structure and physiological

functioning of nerve cells. The critical property of

a neuron is that it has a membrane that is an elec-

trochemical battery. There is a difference in elec-

trical charge between the inside and outside of the

cell created by an uneven distribution of sodium

and potassium ions. Also critical to neural function

are the processes by which this electrochemical

potential can be disturbed so as to trigger an action

potential that can be transmitted from one end of

an axon to the other. Research has demonstrated

that the electrical properties of neurons are based

on voltage controlled ion channels within the

nerve cell membrane. These channels open or

close depending on surrounding voltage levels.

Voltage controlled ion channels are the subject of

intense study in molecular neuroscience since they

are the basis of the resting potential, the excitabil-

ity threshold of the membrane, the phenomena of

the action potential and its transmission, and most

of the critical events at the synapse, where infor-

mation is transmitted from one neuron to another.

Much work in cellular neurophysiology is fo-

cused on events occurring at the synapse. In sim-

ple outline, it has been demonstrated that the ar-

rival of the action potential at the end of the axon

(the terminal button) causes calcium ions to enter

the cell. This causes packets of a transmitter sub-

stance to release their contents into the extremely

small space between neurons. The transmitter sub-

stance attaches to receptors on the post-synaptic

neuron, causing ion gates to open, resulting in a

slight electrical perturbation in this post-synaptic

cell. Various other mechanisms have been found

that clear activated receptors, take back excess

transmitter substance, and recreate the transmitter

substance packets.

Another active area of work in neurophysiol-

ogy is the investigation of the ways that synaptic

functions are modified by learning. Using the nerv-

ous system of a sea slug, it was demonstrated that

learning involved changes in the conductive prop-

erties of synapses. Where in the human nervous

system such synaptic changes can occur, and how

they occur, are important issues in the study of

human learning and memory. An important recent

advance was the identification of the NMDA re-

ceptor that appears to be important in triggering

the synaptic changes involved in learning. NMDA

receptors are present on neurons within the hip-

pocampus, a brain structure that is known to be

important for some forms of memory.

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