Many — if not most — Americans think of the creation and evolution controversy as a dichotomy with "creationists" on one side, and "evolutionists" on the other. This assumption all too often leads to the unfortunate conclusion that because creationists are believers in God, that evolutionists must be atheists. The true situation is much more complicated: creationism comes in many forms, and not all of them reject evolution.
It is highly desirable to move people away from this inaccurate dichotomy. A simple classroom exercise, the Creationism/Evolution Continuum, has been used successfully by middle and high school teachers as well as university professors to illustrate the many intermediate positions between the extremes. It can be scaled up or down in detail, depending on the educational level of the students and the time available to the teacher or professor.
What is critical, however, is that any teacher using this exercise in a public school be acutely aware that the purpose of the lesson is to illustrate to students the factual error of the dichotomy they (probably) came to class with. The purpose is not to change the students' religious views. I cannot stress this too clearly: public schools must be religiously neutral. It is unconstitutional to promote or denigrate religion in the public schools – although it is legal to teach about religion, which is all the Creation/Evolution Continuum is intended to do. A teacher cannot legally promote religion, but can and should descriptively educate students about the variety of religious views relevant to this controversy. It would be unethical as well as illegal to tell students that any particular position on the continuum is religiously superior to another. However, it is not unethical nor illegal to distinguish between fact claims made by holders of certain views on the continuum (such as Young-Earth Creationist views of a 6,000 year old Earth) and the standard scientific consensus on such views (in this case, that the Earth is billions of years old).
With this caveat in mind, then, teachers are encouraged to use the continuum exercise to educate students away from an erroneous dichotomous view of the relationship of creationism to evolution.
Using the Creation/Evolution Continuum
The exercise can be presented very simply: make a transparency of the Creation/Evolution Continuum (Fig. 1) and walk students through each of the stages, describing each one. It is also possible to dress it up with powerpoint, illustrations, etc. However much or little detail the teacher or professor chooses to present, information is presented on each stage from the most dogmatic creationist position to the most dogmatic evolution position. The exercise can be completed in 10 minutes or take a full class period.
Figure 1 presents a continuum of religious views with creationism at one end and evolution at the other. The most extreme views are, of course, at the ends of the continuum. The creation/evolution continuum reflects the degree to which the Bible is interpreted as literally true, with the greatest degree of literalism at the top.
Much of the remainder of this essay is taken from Chapter 3 of Evolution vs. Creationism: An Introduction, second edition, 2009, by Eugenie C. Scott, published by Greenwood (with a paperback version by the University of California Press.)
Although it is a continuum of religious and philosophical beliefs, the Creation/Evolution Continuum inversely reflects how much of modern science holders of these different views accept. I will begin with the strictest biblical literalists, the flat Earthers. (For readers not familiar with the Bible, references take the form of book, chapter: verse; thus, Genesis 1:4 refers to the book of Genesis, chapter 1, verse 4.)
Flat Earthism
Until his death in March 2001, Charles K. Johnson of Lancaster, California, was the head of the International Flat Earth Research Society, an organization with a claimed membership of 3,500 (Martin 2001) that may not long outlive its leader's demise. Johnson — and we assume the members of his society — were very serious about their contention that the shape of Earth is flat rather than spherical, because they are the most strict of biblical literalists. Few other biblical literalists hold to such stringent interpretations of the Bible. To flat Earthers, many passages in the Bible imply that God created an Earth that is shaped like a coin, not a ball: flat and round at the edges. Earth's disklike (not spherical) shape reflects biblical passages referring to the "circle" of the Earth (Isaiah 40:22) and permits one to sail around the planet and return to one's starting point: one merely has to sail to the edge of Earth and make the circuit.
Because their theology requires the Bible to be read as literally true, flat Earthers believe Earth must be flat (Schadewald 1991). The Englishman responsible for the nineteenth-century revival of flat Earthism, Samuel Birley Rowbotham, "cited 76 scriptures in the last chapter of his monumental second edition of Earth Not a Globe" (Schadewald 1987: 27). Many of these refer to "ends of the Earth" (Deuteronomy 28:64, 33:17; Psalms 98:3, 135:7; Jeremiah 25:31) or "quadrants" (Revelation 20:8). For flat Earthers — and other literalists — the Bible takes primacy over the information provided by science; thus, because modern geology, physics, biology, and astronomy contradict a strict biblical interpretation, these sciences are held to be in error.
Geocentrism
Geocentrists accept that Earth is a sphere but deny that the Sun is the center of the solar system. Like flat Earthers, they reject virtually all of modern physics and astronomy as well as biology. Geocentrism is a somewhat larger, though still insignificant, component of modern antievolutionism. At the Bible-Science Association creationism conference in 1985, the plenary session debate was between two geocentrists and two heliocentrists (Bible-Science Association 1985). Similarly, as recently as 1985, the secretary of the still-influential Creation Research Society was a published geocentrist (Kaufmann 1985).
Both flat Earthers and geocentrists reflect to a greater or lesser degree the perception of Earth held by the ancient Hebrews, which was that it was a disk-shaped structure (Figure 2). They believed that the heavens were held up by a dome (raqiya or firmament) that arched over the land and that water surrounded the land. The firmament was perceived as a 
solid, metal-like structure that could be hammered and shaped (as in Job 37:18: "Can you, like him, spread out the skies, hard as a molten mirror?" [All biblical quotes are from the Revised Standard Bible, Zondervan, 1981]). The surface of the firmament is solid enough that God can walk on it (as in Job 22:14: "Thick clouds enwrap him, so that he does not see, he walks on the vault of heaven"). The Sun, Moon, and stars were attached to the firmament, which means that these heavenly bodies circled Earth beneath the firmament and, hence, were part of a geocentric universe. Further support for the idea of a solid sky and a geocentric solar system is found in Revelation 6:13–16: "and the stars of the sky fell to the Earth as the fig tree sheds its winter fruit when shaken by a gale; the sky vanished like a scroll that is rolled up." Stars were regarded as small, bright objects rather than massive suns hugely larger than Earth. They could fall on Earth because they were below the firmament, a solid object that, if rolled aside, would reveal the throne of God (Schadewald 1987, 1981–1982).
The Bible also speaks of the waters above the firmament; ancient Hebrews conceived of the firmament supporting a body of water that came to Earth as rain through the "windows of heaven" and was the source of the forty days and nights of rain that began Noah's Flood.
Ancient and modern geocentricity reflects the idea that the Earth and its creatures — especially humans — are central to God. To symbolize this importance, God would have made Earth the center of the universe. Taking Earth out of this central position reduces its importance, which reduces (according to their interpretation) man's place as the most important element in creation. Although not actively supporting
geocentrism, young-Earth creationist astronomer D. Russell Humphreys has promoted the idea of the centrality of Earth and humans by claiming that Earth is at the center of the universe (Humphreys, 2002). His conception of cosmology has the central Earth surrounded by galaxies and ultimately a sphere of water that is light-years in diameter (the "waters which were above the firmament" of Genesis 1:7) (Humphreys, 2007; see Figure 3).
The next group of creationists on the continuum are less biblically literalist than the previous two, but all three endorse the theological doctrine of special creationism, which stresses the view that God created the universe, Earth, plants and animals, and humans in essentially their present form. The most common form of special creationism holds that the creation event took place relatively recently, and is thus called young-Earth creationism.
Young-Earth Creationism
Few proponents of young-Earth creationism interpret the flat Earth and geocentric passages of the Bible literally. They accept heliocentrism but reject the conclusions of modern physics, astronomy, chemistry, and geology concerning the age of Earth, and they deny biological descent with modification. Earth, in their view, is between 6,000 and 10,000 years old. They reject the Big Bang theory and postulate catastrophic mechanisms as the cause of most of the world's geological features. The Flood of Noah, for example, is allegedly responsible for carving the Grand Canyon and other geological features.
Young-Earth creationists (YECs) reject the inference that earlier forms of life are ancestral to later ones. Instead, they embrace the special creation of separate "kinds" of plants and animals, as stated in Genesis. The definition of kinds is inconsistent among YECs but usually refers to a higher taxonomic level than species. Most YECs accept that God created creatures possessing at least as much genetic variation as occurs within a biological family (for example, the cat family Felidae, the cattle family Bovidae) and then considerable evolution within a kind occurred. The created cat kind thus would have possessed sufficient genetic variability to differentiate into lions, tigers, leopards, pumas, bobcats, and house cats, through the normal microevolutionary processes of mutation and recombination, natural selection, genetic drift, and speciation. Most YECs view the basic body plans of major phyla that appear in the Cambrian explosion as evidence of special creation.
The term young-Earth creationist is often associated with the followers of Henry Morris, founder of the Institute for Creation Research (ICR) and arguably the most influential creationist of the second half of the twentieth century. He and John C. Whitcomb published The Genesis Flood, a seminal work that claimed to provide a scientific rationale for young-Earth creationism (Whitcomb and Morris 1961). As the title suggests, the authors read Genesis literally, including not just the special, separate creation of humans and all other kinds of plants and animals but also the historicity of Noah's Flood. Whitcomb and Morris proposed that there is scientific evidence to demonstrate the truth of special creationism: Earth is young, the universe appeared in essentially its present form about 10,000 years ago, and plants and animals appeared in their present forms as created kinds rather than having evolved over millions of years through common ancestors. Although efforts were made during the eighteenth and nineteenth century to claim that a literal interpretation of the Bible is compatible with science, The Genesis Flood was the first twentieth-century effort to attract a large following. Religious antievolutionists were greatly encouraged by the thought that there might be evidence that evolution was not only religiously objectionable but also scientifically flawed. Creation science has been augmented by hundreds of books and pamphlets written by Morris and those inspired by him (McIver 1988).
Old-Earth Creationism
The idea that Earth is ancient was well established in science by the mid-1800s and was not considered a radical idea in either the Church of England or the Catholic Church (Eiseley 1961). From the mid-1700s on, the theology of special creationism has been partly harmonized with scientific data and theory showing that Earth is ancient. To many Christians, the most critical element of special creation is God's personal involvement in Creation; precise details of how God created are considered secondary. The present may indeed be different from the past, but old-Earth creationists (OECs) see God as a direct causal agent of the observed changes.
The creation/evolution continuum, like most continua, has few sharp boundaries. Although there is a sharp division between YECs and OECs, the separation among the various OEC persuasions is less clear cut. Even though OECs accept most of modern physics, chemistry, and geology, they are not very dissimilar to YECs in their rejection of biological evolution. There are several religious views that can be classed as OEC.
Gap Creationism
One of the better-known nineteenth-century accommodations allowing Christianity to accept the science of its time was gap or restitution creationism, which claimed that there was a large temporal gap between verses 1 and 2 of chapter 1 of Genesis (Young 1982). Articulated from approximately the late eighteenth century on, gap creationism assumes a pre-Adamic creation that was destroyed before Genesis 1:2, when God re-created the world in six days and created Adam and Eve. A time gap between two separate creations allows for an accommodation of special creationism with the evidence for an ancient age of Earth. In gap creationism, the six days of Genesis 1:2 and following are considered twenty-four-hour days.
Day-Age Creationism
Another attempt to accommodate science to a literal, or mostly literal, reading of the Bible is the day-age theory, which was more popular than gap creationism in the nineteenth century and the earlier part of the twentieth (Young 1982). Here religion is accommodated to science by having each of the six days of creation be not twenty-four hours but long periods of time — even thousands or millions of years. This allows for recognition of an ancient age of Earth but still retains a quite literal interpretation of Genesis. Many literalists have found comfort in what they interpret as a rough parallel between organic evolution and Genesis, in which plants appear before animals, and human beings appear afterward. Anomalies such as flowering plants being created before animals and birds occurring before land animals — incidents unsupported by the fossil record — are usually ignored.
Progressive Creationism
Although some modern activist antievolutionists may still hold to day-age and gap views, the view held by the majority of today's OECs is some form of progressive creationism (PC). The PC view accepts more of modern science than do day-age and gap creationism: progressive creationists do not dispute scientific data concerning the big bang, the age of Earth, or the long period of time it has taken for Earth to come to its current form. Indeed, some cite the big bang as confirmation of Genesis, in that the big bang is viewed as the origin of matter, energy, and time, which in the PC view is equivalent to creation ex nihilo, the doctrine of creation out of nothing. As in other forms of old-Earth creationism, although theories of modern physical science are accepted, PC incorporates only parts of modern biological science.
For example, the fossil record shows a consistent distribution of plants and animals through time: mammals are never found in the Cambrian, for example, and flowering plants are never found in the Devonian. However, YECs believe that flowering plants, dinosaurs, humans, and trilobites were all created at the same time and therefore all lived at the same time. They regard the orderly distribution of fossils in strata around the world to be an artifact of Noah's Flood, which is thought to have differentially sorted organisms into groups, even if they all died at the same time. In contrast, PCs generally accept the fossil distribution of organisms as "real" because they believe that God created kinds of animals sequentially. To PCs, the geological column reflects history: God first created simple, single-celled organisms, then more complex single-celled life, then simple multicellular organisms, then more complex ones, and so on up until the present time. With PC, there is no difficulty that seed-bearing plants appear after ferns and cycads: God created the more "advanced" plants at a later time. However, progressive creationists do not accept that the kinds evolved from one another, though they are no more specific than YECs about what constitutes a kind. As in young-Earth creationism, though, a kind is viewed as genetically limited: as a result, one kind cannot change into another.
Evolutionary Creationism
Despite its name, evolutionary creationism (EC) is actually a type of evolution. Here, God the Creator uses evolution to bring about the universe according to God's plan. From a scientific point of view, evolutionary creationism is hardly distinguishable from theistic evolution, which follows it on the continuum. The differences between EC and theistic evolution lie not in science but in theology, with EC being held by more conservative (Evangelical) Christians, who view God as being more actively involved in evolution than do most theistic evolutionists (Lamoureux, 2008).
Intelligent design creationism has been positioned on the continuum as overlapping YEC and OEC because some of its proponents can be found in each camp; old-Earthers among the intelligent design creationists have not categorically denied the scientific validity of YEC.
Intelligent Design Creationism
Intelligent design creationism (IDC) is the newest manifestation of American creationism, and yet it resembles a much earlier idea. In most ways, IDC is a descendant of William Paley's argument from design (Paley 1803), which argued that God's existence could be proved by examining God's works. Paley used a metaphor: if one found a watch, it was obvious that such a complex object could not have come together by chance; the existence of a watch implied a watchmaker who had designed the watch with a purpose in mind. By analogy, the finding of order, purpose, and design in the world was proof of an omniscient designer.
The vertebrate eye was Paley's classic example of design in nature, well known to educated people in the nineteenth century. Because of its familiarity, Darwin deliberately used the vertebrate eye in On the Origin of Species to demonstrate how complexity and intricate design could indeed come about through a natural process; complexity in nature did not require divine intervention.
Structures and organs that accomplish a purpose for the organism — allowing capture of prey, escape from predators, or attracting a mate — could be designed directly by an omniscient designer, or they could be "designed" by a natural process that produces the same effect. As will be discussed in more detail elsewhere in this book, Darwin's argument that a natural process such as natural selection could explain apparent design was theologically offensive to those who believed that God created directly.
In IDC one is less likely to find references to the vertebrate eye and more likely to find molecular phenomena such as DNA structure or complex cellular mechanisms held up as too complex to have evolved "by chance." The IDC high school biology supplemental textbooks Of Pandas and People (Davis and Kenyon 1993) and Explore Evolution (Meyer, Minnich, Moneymaker, Nelson, and Seelke 2007) both attempt to prove that DNA is too complex to explain through natural causes by weaving allusions to information theory into an exposition of the "linguistics" of the DNA code.
Following creationist tradition, IDC proponents accept natural selection but deny that mutation and natural selection are adequate to explain the evolution of one kind to another, such as chordates from echinoderms or humans and chimps from a common ancestor. The emergence of major anatomical body types and the origin of life, to choose just two examples popular among IDC followers, are phenomena supposedly too complex to be explained naturally; thus, IDC demands that a role be left for the intelligent designer — God.
Theistic Evolution
Theistic evolution is a theological view in which God creates through the laws of nature. Theistic evolutionists (TEs) accept all the results of modern science, in anthropology and biology as well as in astronomy, physics, and geology. In particular, it is acceptable to TEs that one species give rise to another; they accept descent with modification. However, TEs vary in whether and how much God is allowed to intervene — some believe that God created the laws of nature and allows events to occur with no further intervention. Other TEs believe that God intervenes at critical intervals during the history of life (especially in the origin of humans). A 2003 book presents an entire continuum of TEs; clearly, there is much variation among Christians regarding this theological view (Peters and Hewlett 2003). In one form or another, TE is the view of creation taught at the majority of mainline Protestant seminaries, and it is the position of the Catholic Church. In 1996, Pope John Paul II (1996) reiterated the Catholic version of theistic evolution, in which God created, evolution happened, humans may indeed be descended from more primitive forms, but the hand of God was required for the production of the human soul. The current pope, Benedict XVI, has reiterated the evolution-friendly Catholic view, stressing the importance of rejecting philosophical naturalism (Lawton, 2007).
Agnostic Evolutionism
Although poll data indicate that most Americans have a belief in God or some higher power, a (perhaps growing) minority do not (Pew Forum on Religion and Public Life 2008). The term agnostic was coined by "Darwin's bulldog", the nineteenth-century scientist Thomas Henry Huxley, to refer to someone who suspended judgment about the existence of God. Huxley felt that human beings, part of the material universe, would be unable to grasp ultimate reality; therefore, neither belief in nor rejection of the existence of God is warranted. To Huxley, the thoughtful person should suspend judgment. Huxley was a strong supporter of science and believed that knowledge and beliefs should be based on empirical knowledge — and that science would eventually supplant supernaturalism. But he felt it was more honest not to categorically reject an ultimate force or power beyond the material world:
I have no doubt that scientific criticism will prove destructive to the forms of supernaturalism which enter into the constitution of existing religions. On trial of any so-called miracle the verdict of science is "Not proven." But true Agnosticism will not forget that existence, motion, and law-abiding operation in nature are more stupendous miracles than any recounted by the mythologies, and that there may be things, not only in the heavens and Earth, but beyond the intelligible universe, which "are not dreamt of in our philosophy." The theological "gnosis" would have us believe that the world is a conjuror's house; the anti-theological "gnosis" talks as if it were a "dirt-pie" made by the two blind children, Law and Force. Agnosticism simply says that we know nothing of what may be beyond phenomena. (Huxley 1884)
Agnostics believe that, in this life, it is impossible to know truly whether there is a God, and although they believe that it is not probable that God exists, they tend not to be dogmatic about this conclusion. One can find individuals who accept the scientific evidence that evolution occurred but do not consider important the question of whether God is or was or will be involved. We can call this belief agnostic evolutionism. Holders of this view differ from the next position on the continuum by not categorically ruling out the involvement of God, although they tend to side with those who doubt the existence of God and whether God acts in the world.
Materialist Evolutionism
Before discussing materialist evolutionism, I need to distinguish between two uses of the term materialism (or naturalism). As I mentioned in chapter 1, modern science operates under a rule of methodological naturalism that limits it to attempting to explain natural phenomena using natural causes. Philosophical materialists (sometimes referred to as philosophical naturalists) go beyond the methodological naturalism of science to propose not only that material (matter and energy) causes are sufficient to explain natural phenomena but also that the supernatural does not exist. To a philosophical naturalist, there is no God. The philosophy of humanism is a materialistic philosophy, as is atheism. As discussed earlier in this chapter [not presented in this excerpt], philosophical naturalism is distinct from the practical rules of how to do science.
This is an important distinction to the subject of this book because some antievolutionists accuse evolution and science in general of being not only methodologically naturalistic but also philosophically naturalistic. This is a logical error, as Figure 4 shows. It is very likely the case that all philosophical naturalists are simultaneously methodological 
naturalists (all Ps are Ms). It does not follow that all methodological naturalists are philosophical naturalists (not all Ms are Ps). It might be the case — if both circles were the same size and right on top of one another — but this would have to be determined empirically, not logically. In fact, such a claim is empirically falsified, for there are many scientists who accept methodological naturalism in their work but who are theists and therefore not philosophical naturalists. Gregor Mendel — the monk whose research became the foundation of genetics — is a classic case of a scientist who was a methodological naturalist but not a philosophical one, and there are many scientists today who, like him, are methodological but not philosophical naturalists.
As mentioned, there are varieties of belief within the various theistic positions on the continuum, and this is true for materialists as well. For example, although materialists share a high opinion of science and accept evolution, they do not all share the same attitudes toward religion. Agnostics are materialists who do not consider that the question of whether God created can be answered. Humanists have a philosophy of life and an ethical code that holds, "Humanism is a progressive lifestance that, without supernaturalism, affirms our ability and responsibility to lead meaningful, ethical lives capable of adding to the greater good of humanity" (American Humanist Association 2002). The two major humanist organizations are the American Humanist Association, with approximately 5,000 members at the time of this writing, and the Council for Secular Humanism, with approximately 4,000 members.
Atheists, the third major group within materialists, reject the existence of God but tend to be more actively antireligious than the other two. There are about 2,200 members of the best- known atheist group, the American Atheists. Clearly, any single theist organization has far more members than all the materialist organizations combined. If nonbelievers make up between 10 percent and 14 percent of the population, as some polls suggest, the vast majority of them do not join groups of like-minded individuals. Someone holding to materialist evolutionism, then, believes that evolution occurred but that there was absolutely no supernatural entities or forces affecting it, because such forces do not exist. As we will see later in this book [not presented in this excerpt], creationists consider materialist evolutionism the true enemy of religion; actually, although all material evolutionists reject the involvement of God in evolution, not all material evolutionists are antireligious.
This presentation of Christian and materialist views regarding creation and evolution is simplified — as was the earlier presentation of the nature of science in chapter 1 and the presentation of the science of evolution in chapter 2. It is possible to go into far more detail on any of these beliefs, but a shorthand version will have to suffice to introduce the topic.
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