Chapter Two
Naturalism
IMPORTANT DATES IN ANCIENT ATOMISM
490-430 B.C. 460-360 B.C. 341-271 B.C. 306 B.C.
96-55 B.C.
Birth and death of Leucippus Birth and death of Democritus Birth and death of Epicurus Epicurus founds his university, the Garden, in Athens Birth and death of T. Lucretius Carus
I f we accept the fairly widespread tradition that Democritus lived more than one hundred years ( 460-360 B.c.), his life overlapped the lives of Socrates, Plato, and Aristotle. This chapter helps set the stage for the fol- lowing chapter's treatment of Plato's philosophy. This is so because Plato opposed every distinctive claim of naturalism, including the theories of Democritus that we will examine in this chapter.
Versions of the theories discussed in this chapter are still popular. It is important to recognize how much of contemporary naturalism is largely a restatement, however more sophisticated it may appear, of ideas known and opposed by all of the other systems discussed in chapters 3-7. Because naturalism is such a powerful and influential system, it makes sense to begin with a look at contemporary naturalism. Among other things, this will help establish a definition for the term. As dead as many ideas of the ancient naturalists may seem, the worldview they represented is alive.
For much of the twentieth century, the worldview of naturalism has been the major antagonist of the Christian faith in those parts of the world described by the label of Christendom. The central claim of meta- physical naturalism is that nothing exists outside the material, mechanis-
Why Begin with Naturalism?
Contemporary Metaphysical Naturalism
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tic (that is , nonpurposeful), natural order. My discussion will focus on naturalists who are what we call physicalists, people who insist that every- thing that exists can be reduced to physical or material entities. But some thinkers reject physicalism (that is, they deny the physicalist's claim that all of reality can be reduced to material entities) yet are also naturalists because they deny the possibility of any divine intervention in the natural order. The famous deists of the eighteenth century were naturalists in this second sense. So too are certain liberal Christian theologians of the twen- tieth century such as Paul Tillich and Rudolf Bultmann. Because we live in a day when physicalists control the agenda, I am justified in concen- trating on this first kind of naturalist.
A naturalist believes that the physical universe is the sum total of all that is. In the famous words of Carl Sagan 0934-1996), "The universe is all that is, or ever was, or ever will be. " In the naturalist view of things, Christian supernaturalism is false by definition, as are miracles and the existence of the Judea-Christian God. Since the matter that makes up the universe is eternal, any belief in a divine creation of the universe is false by definition.
One of the better accounts of contemporary naturalism can be found in a book by the British author C. S. Lewis:
What the Naturalist believes is that the ultimate Fact, the thing you can't go behind, is a vast process in space and time which is going on of its own accord. Inside that total system every particular event (such as your sitting reading this book) happens because some other event has hap- pened; in the long run, because the Total Event is happening. Each par- ticular thing (such as this page) is what it is because other things are what they are; and so, eventually, because the whole system is what it is . All the things and events are so completely interlocked that no one of them can claim the slightest independence from "the whole show." None of them exists "on its own" or "goes on of its own" except in the sense that it exhibits at some particular place and time, that general "existence on its own" or "behaviour of its own accord" which belongs to "Nature ," the great total interlocked event as a whole .I
For a naturalist, the universe is analogous to a sealed box. Everything that happens inside the box (the natural order) is caused by or is explic- able in terms of other things that exist within the box. Nothing, includ- ing God, exists outside the box; therefore, nothing outside the box that we call the universe or nature can have any causal effect within the box. The resulting picture of metaphysical naturalism looks like this:
1. C. S. Lewis, Miracles (New York: Macmillan, 1960), 6-7.
NOTHING
NATURALISM
NATURE (The Physical
Universe) NOTHING
It is important to notice that the box is closed and sealed tightly. Even if something did exist outside the box, it could not serve as the cause of any event that occurs within the box.
I must pause a moment to consider a possible objection or two to this picture. Some critics will point out that such early naturalists as Dem- ocritus and Epicurus believed the universe was infinitely large . Surely, my critics could say, you distort at least their version of naturalism by portraying their universe as a closed box. Other critics might complain that my analogy of the box distorts the naturalist's understanding of the universe by implying both an inside and an outside of the natural order, although for a true naturalist there is no outside. Nonetheless, the picture of the box has helped large numbers of naturalists to comprehend the essential features of their worldview, or so many have told me.
This is a good opportunity to clarify what my illustration is about. Whether the universe of a naturalist is infinite or finite, nothing exists that is independent of the natural order and its processes. We will see this clearly when we sn1dy ancient atomism, which taught that all of nature consists of eternal, indestructible, corporeal atoms moving through empty space. Nothing can exist that is not a result of some mechanistic, non- purposeful combining of these eternal atoms . As we'll see, Epicurus believed in the existence of the Greek gods. 2 However, he taught, even the gods are composed of atoms; even the gods are contained within the box that is the natural order. Understood properly, my example of the closed box illustrates important features of naturalism.
Naturalists believe that everything that happens within nature has its cause in something else that exists within the natural order. As philoso- pher William Halverson explains, metaphysical naturalism claims
that what happens in the world is theoretically explicable without residue in terms of the internal structures and the external relations of these material entities. The world is ... like a gigantic machine whose parts are so numerous and whose processes are so complex that we have thus far been able to achieve only a very partial and fragmentary under- standing of how it works. In principle, however, everything that occurs
2. I am not suggesting that Epicurus believed in the Greek gods in the sense that mod- ern-day Christians believe in God. But it seems clear that he be lieved that the ancient Greek gods did exist in some sense.
Figure 2.1
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is ultimately explicable in terms of the properties and relations of the particles of which matter is composed.3
A metaphysical naturalist, then, believes the following propositions. 1. Only nature exists. By nature I mean (following Stephen Davis)
"the sum total of what could in principle be observed by human beings or be studied by methods analogous to those used in the natural sci- ences. "4 Anyone who adopts a naturalist worldview holds that a super- natural God (that is, the kind of God found in theistic religions like Judaism and Christianity whose existence is independent of nature and whose creative activity brought the universe into existence from nothing) does not exist. By definition, anything that exists is part of the box.
2. Nature is a materialistic system. The basic components of existing things are material entities. This does not mean that metaphysical natu- ralists deny the existence of such things as human memories of the past and hopes for the future , or plans, intentions, and logical inferences. Whatever such things as thoughts , beliefs, and inferences are, they are either material things or reducible to or explainable in terms of material things or caused by something material.
3. Nature is a system. Anything that happens within the natural order must, at least in principle, be explainable in terms of other elements of the natural order. It is never necessary to seek the explanation for any event within nature in something beyond the natural order. In gen- eral, the naturalist holds that only the parts and not the whole require expla- nation in terms of something else (which brings us back to the brute factuality of the universe, whether it has an absolute beginning or not). It is neither necessary nor possible to seek an explanation in terms of some- thing beyond the natural order. Even though naturalists insist that every individual and event in the system be explained, they deny both the neces- sity and the possibility of explaining the whole in terms of something else.
In this connection, it would be easy to assume that metaphysical nat- uralists must also believe that the natural order is eternal. But naturalism is more complex than this. It is true that many naturalists prefer to think of the universe as always existing in some state or other. However, many of them reserve the right to claim that even though the universe had a beginning, it sprang into existence uncaused. The naturalist position about the age of the natural order amounts to the claim that either the uni- verse has always existed or it came into existence without a cause. It should be noted, however, that one does not need to be a theist to have
3. William H. Halverson, A Concise Introduction to Philosophy, 3d ed. (New York: Ran- dom House, 1976), 394.
4. Stephen T. Davis, "Is It Possible to Know That Jesus Was Raised from the Dead?" Faith and Philosophy 1 (1984): 154.
NATURALISM
trouble understanding or accepting the belief that an uncaused universe sprang into existence from nothing.
4. Nature is characterized by total uniformity. This uniformity is apparent in the regularity of the natural order, something that scientists attempt to capture in the natural laws they formulate. Many philosophers at this point mistakenly infer that a belief in miracles is incompatible with the order and regularity of the natural order.
5. Nature is a deterministic system. Determinism is the belief that every event is made physically necessary by one or more antecedent causes. Because the metaphysical naturalism under consideration here is a kind of physicalism, those antecedent causes must be either matter or reducible to matter. In this view of things, there is no room for any the- ory of agency whereby either God or human beings acting apart from any totally determining causes can function as causes in the natural order.s
One of the most important benefits of responsible worldview think- ing is recognizing the logical implications of one's major beliefs. How well does naturalism meet the tests of reason, outer experience, inner experience, and practice? Once naturalists commit to their naturalistic pre- suppositions, what implications are they obliged to accept, to live with?
Any persons in the grip of these naturalistic habits of mind could not be expected to believe in the existence of the personal, omnipotent God of Judaism and Christianity or in miracles, angels, conscious existence after death, or any other essential feature of the historic Christian faith. For such persons, evidence of putative miracles can never be persuasive. Since such persons believe that miracles are impossible, it is impossible that there should ever be convincing evidence for a miracle. Thus, no arguments on behalf of the miraculous can possibly succeed with a naturalist on the nat- uralist's own terms. The only proper way to address the naturalists' dis- belief is to begin by challenging the elements of their naturalism.
One way for the reader to see important features of naturalism is to dwell in the mood and atmosphere of the following quotations from two naturalistic philosophers of the twentieth century, Corliss Lamont and Bertrand Russell. Lamont expresses clearly the naturalist's need to reject all forms of supernaturalism. "Humanism," he writes, "believes in a nat- uralistic metaphysics or attitude toward the universe that considers all forms of the supernatural as myth; and that regards Nature as the totality of being and as a constantly changing system of matter and energy which exists independently of any mind or consciousness."6 Moreover, Lamont
5. Contemporary physics wrestles with so many apparent anomalies that it is possible for someone to be a naturalist and question both determinism and the uniformity of the natural order. But the comments in points 4 and 5 have been appropriate for too long to omit.
6. Corliss Lamont, 7he Philosophy of Humanism, 6th ed. (New York: Fredrick Ungar, 1982), 12-13.
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PART ONE: SIX CONCEPTUAL SYSTEMS
continues, "Humanism, drawing especially upon the laws and facts of sci- ence, believes that man is an evolutionary product of the Nature of which he is part; that his mind is indivisibly conjoined with the functioning of his brain; and that as an inseparable unity of body and personality he can have no conscious survival after death. "7
Two quotations from Bertrand Russell also provide important confir- mation of my account of contemporary naturalism. In the first quote, Rus- sell says:
That man is the product of causes which had no prevision of the end they were achieving; that his origin, his growth, his hopes and fears , his loves and his beliefs are but the outcome of accidental collocations of atoms; that no fire, no heroism, no intensity of thought and feeling, can preserve an individual life beyond the grave; that all the labours of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system, and the whole temple of Man's achievement must inevitably be buried beneath the debris of a universe in ruins-all these things, if not quite beyond dispute, are yet so nearly certain, that no philosophy which rejects them can hope to stand. Only within the scaffolding of these truths, only on the firm foundation of the unyielding despair, can the soul's habitation henceforth be safely built.8
In the second passage Russell is even gloomier:
Brief and powerless is Man's life; on him and all his race the slow, sure doom falls pitiless and dark. Blind to good and evil, reckless of destruc- tion, omnipotent matter rolls on its relentless way; for Man, condemned today to lose his dearest tomorrow, himself to pass through the gate of darkness , it remains only to cherish, ere yet the blow falls, the lofty thoughts that ennoble his little day.9
To Russell's credit, he was not reticent to reveal the practical outcome for life of the naturalistic worldview.
M ost of us know that prior to Albert Einstein and other scientists who effected the revolution in physics leading to the nuclear age, nineteenth- century science explained the physical universe as a collection of indivisible atoms that in various combinations made up everything that exists. Many stu- dents do not realize that a similar kind of atomism, simpler in specifics, existed in ancient Greece during the lifetimes of Socrates and Plato and was revived and modified by the school of philosophy known as Epicureanism.
7 Ibid., 13. 8. Bertrand Russell, Mysticism and Logic (London: Longmans, Green and Co. , 1925),
47-48. 9. Ibid. , 56-57.
NATURALISM
Most of the philosophers who came before Socrates, Plato, and Aris- totle are described as naturalists. One reason for this was their focus on nature, the physical universe. They were interested in the heavenly bod- ies they observed at night, and they wondered what the things they encountered in their experience were composed of. They tended to say comparatively little about such human issues as knowledge and ethics. One reason such thinkers were called naturalists is because they centered their attention on nature rather than on human problems. Naturalism in this pre-Socratic sense is rather benign, even though we might regret the narrow focus of these philosophers' work. 1o
But another sense of naturalism characterized early Greek thinkers, a sense that will occupy us in this chapter and several others. The early Greek thinkers often thought that the natural world or physical universe is the only reality that exists. One consequence of this was their denial that anything exists outside the bounds of the physical universe. I have already noted similar thinking in representatives of twentieth-centuty nat- uralism.
The two names associated with ancient Greek atomism were Leu- cippus (490-430 B.c.) and Democritus (460-360 B.c.). Since it may be impossible to separate their views and since Democritus is usually regarded as the more important of the two, I'll concentrate upon his work.
Democritus Democritus was the most accomplished of the early naturalists. To quote one historian of philosophy, "No one, even in modern times, has given a more classic expression to atomism or mechanism [than has Democri- tus]. The motivation of materialistic or mechanistic systems is to explain all phenomena in terms of mechanism; that is, the only original differ- ences allowed to the elements are strictly geometrical, plus the motion in space necessary to alter their positions. For Democritus therefore two principles explain everything: atoms and empty space ."11
Democritus proposed that the basic building blocks of the universe are tiny, indivisible material entities called atoms. (The word atom means that which cannot be divided.) Atomists explained every feature of the material world as varying combinations of an infinite number of atoms moving haphazardly through empty space. The atoms, we must under- stand, had no properties such as color, taste, or smell; they were neither hot nor cold, sweet nor sour. But every physical thing we encounter in
10. In the time of Socrates and Plato, the word phusis (nature) had begun to take on a wider meaning, so that it became more difficult to distinguish between issues pertinent to nonhuman nature and issues pertinent to humans.
11. Gordon H. Clark, Thales to Dewey, 2cl eel. (Unicoi , Tenn.: The Trinity Foundation, 1989), 35.
Demoaitus Marble bust, Roman period THE G RANGER COLLECflON, NEW Y ORK
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our experience does have such qualities. The atomists explained such properties as the way things appear to us as a result of the chance link- age of the atoms that possess no such properties.
Atoms differ, the ancients taught, only in quantitative terms like size and shape, never in quality. Atoms are also uncreated and indestructible, which translates into their being eternal. They had no beginning and will have no end. According to the atomists, then, everything in the world can be explained as a chance combination of qualitatively identical atoms.
The Question That Has No Answer Contemporary naturalists excel at posing problems for which they sup- pose there is no answer. But atomists and naturalists have their own ques- tions for which they have no answer. Why is there something (atoms) rather than nothing? Why do the atoms move rather than sit there? If you 're an atomist, this is what you have to believe.
It is interesting to observe those important times when even antireli- gious thinkers like naturalists find it necessary to make leaps of faith . These leaps occur when their thinking leads them to questions for which their system has no answer. Usually they find it convenient to pretend the question doesn't exist. One such question is why atoms exist. Another is why atoms move.
One must never ask why atoms move. Their random movement is a given. Atoms move in all directions. Much like billiard balls on a pool table, the atoms collide with other atoms. These collisions may result in some atoms hooking up in new combinations, or a collision might cause an atom to ricochet in a new direction. The chance conjoining of atoms produces the many different things that exist in the world. The combi- nations of atoms finally break up, and when this happens, the individual thing that they composed ceases to exist. But the individual atoms exist forever.
So, according to Democritus, the truth about the physical universe can be summed up in two words, "atoms" and the "void." Everything in the universe is a result of qualitatively indistinguishable atoms moving around the universe, bouncing into other atoms, briefly linking up with other atoms. The taste of an orange, the color of a tulip, and the fragrance of a rose are reducible to the quantitatively different factors to which evety- thing that exists can be reduced. All quality is an illusion. It is the way cer- tain configurations of quantitatively different atoms appear to people .
The ancient atomists had another problem. Their universe was a machine, devoid of purpose and design. But the universe we live in is full of order. Consider two piles of apples and oranges. If we took the mech- anistic, purposeless metaphysics of the ancient atomists literally, they had no explanation for why apple seeds don't produce orange trees. But that
NATURALISM
never happens in the real world. Not only did the atomists have difficulty explaining why there were atoms or why the atoms moved so conve- niently, but also they seemed to have no way to explain the lawlike and orderly nature of the universe.
The world we perceive is rich with color, tastes, sounds, and other properties. But the world of the atomists is colorless, tasteless, and devoid of sound. As W. T. Jones explains, "When the atoms flung off by the pat- tern that we call a rose strike those other atoms that we call an eye, the former set up a motion in the latter (as a billiard ball flung into a group of stationary balls sets them in motion), and this motion, communicated to other atoms by way of the optic nerve (itself, of course, really another collection of atoms with another configuration), eventually produces the sensation that we know and experience as 'rose. "'12
The atomism of Democritus was a mechanistic view of the universe. It portrayed the universe as a machine, purring along in ways that seemed to produce order and design, but this view is without any ability to explain that order and design. Taken literally, the system encouraged people to expect not order but chaos. As we'll see, Plato opposed the mechanism of the atomistic worldview in favor of a teleological world- view, one requiring a source for order and design that transcends the physical world.
It is worth considering whether our contemporary understanding of DNA is good news or bad news for naturalists. Some have argued that a proper understanding of DNA requires as part of its explanation the posit- ing of a power beyond tl1e physical universe. And since this force would appear to explain what appear to be order, design, and intelligence (in the case of humans) in the universe, this transcendent cause might be a mind.
Atomism reappeared in the philosophy of Epicurus (341-271 B.c.). Epi-curus introduced some changes in atomistic theory that had the effect of creating new difficulties for the defenders of atomism.
In one important sense, Epicureanism was the search for a worldview that would deliver humans from their fear of death and the gods. This treatment of death still has appeal for secularists. According to Epicurus, we need not fear death because, in his words, "When death is, we are not and when we are, death is not. "13 The point is that as long as we are con- scious, we are not dead, but when we are dead, we are no longer con- scious of anything. There is no need therefore to fear what might happen after we are dead, because the atoms that made up our soul and body
12. W. T. Jones, A HistoryofWesternPhilosophy, vol. 1, The Classical Mind, 2d ed. (New York: Harcourt Brace & World, 1969), 91.
13. Epicurus Letter to Menoeceus.
Epicureanism
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have broken apart. Nor should we grieve over the events that will follow our death. Rational persons do not grieve over the centuries that passed before their lives began; why then should we grieve over the centuries that will pass after we have ceased to exist?
The Epicureans tended to accept the existence of the traditional Greek gods. Does this not then disqualify them as naturalists, some might ask? Such finite deities are confined within the box and are therefore reli- giously, metaphysically, and ethically irrelevant, especially the latter.
Even though the materialistic, atomistic, mechanical system adopted by Epicurus denied purpose (teleology) in the world, it was not com- pletely mechanical. Epicurus thought it important to free humans from mechanistic determinism, which he viewed as a threat to human happi- ness. In order to provide an argument freeing humans from the machine of the atomistic universe, he had to find a way to introduce indetermin- ism into the movement of the atoms. After all, humans are made of atoms. Therefore, in order for humans to be free, the movement of atoms must be undetermined-at least in some cases.
In order to make room for interdeterminism and human freedom, Epicurus introduced a significant change in atomistic metaphysics. As we've seen, Democritus's atoms moved helter-skelter, in all directions, through empty space . Epicurus added weight as a property of atoms, which he thought led to each atom falling downward in a straight line at the same speed. It is relatively easy to understand how the atoms of Dem- ocritus can bump into other atoms and join together. But picture an infi- nite number of atoms falling in a straight line in infinite space. We have a new question for which there is no answer: How do Epicurus's atoms collide and enter into combinations? Epicurus's convenient answer is what has been called the declination of the atom. Occasionally, in an unpre- dictable and inexplicable fashion, atoms swerve out of their straight downward path. Such deviations or swerves bring about collisions and vortices; 14 eventually some of these vortices become a world. The decli- nation of the atoms became the device by which Epicurus attempted to guarantee some measure of human freedom.
The indeterministic twist Epicurus added to atomism allows humans to pursue pleasure, which for Epicurus was the highest good. The belief that pleasure is the highest good is known as hedonism. As Gordon H. Clark explains:
Epicurus attempted to remove the three greatest, perhaps the three only, impediments to a happy life. The first obstacle is pessimism, which can result only in an unhappy consciousness. But freedom from mechanical
14. The vortex in view here is a kind of spinning motion in a group of atoms that pulls them together.
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law, obtained by rejecting uniform causality, gives the feeling that our choices and endeavors count, and that life is worth living . ... Second, by showing as Lucretius does at length, that all phenomena can be explained without recourse to divine providence, the fear of the gods with its superstition and attendant inquietude is removed1 5 It is under this heading that all the specifically scientific investigations must be placed ... . The third great obstacle to happiness, strictly related to the other two, namely the fear of death, is overcome by the same methods. Death can cause us the pain of fear now while we are living only if it will cause us pain in an afterlife. Obviously it is unreasonable to fear a future event which will not pain us when it happens. And a thorough study of psychology shows this to be the case. Man is nothing but a collection of atoms; their motions are sufficient to explain animation, sensation, and thought. To be sure man has a soul and a spirit but they are neither immaterial nor immortal. Consequently, when death comes the atoms disperse, and man as a sensitive being no longer exists to suffer either the wrath of the gods or any other unknown eviJ. 16
Another Question That Has No Answer Earlier I introduced the notion of the question that has no answer. The first naturalistic question to which there is no answer is why the atoms exist. Why is there something rather than nothing? The second is why the atoms move. In one sense they have to move, because if they didn't move, nothing else, including naturalistic philosophers, would exist. But this is no answer to the question; it points to the atomist's situation from which the inexplicable motion of the atoms is his only escape. Epicurus now introduces us to another question that has no answer: Why do the atoms swerve? There is no reason, except that otherwise nothing else would exist.
In infinite space, we should notice, the words up and down have no meaning.17 But Epicurus did use the word falling, and he implied that the atoms were falling down. Down toward what? The polite thing is not to ask. As Jones observes, "Why should an atom swerve-except to get the atomic theory out of an insoluble difficulty? Unfortunately, the doctrine of the swerve extricated the theory from one difficulty only by plunging it into another, equally grave. "18
15. It is important at this point not to confuse the thinking of Lucretius on this issue with that of Epicurus.
16. Gordon H. Clark, Selections from Hellenistic Philosophy (New York: Appleton-Cen- tury-Crofts, 1940), Introduction, 6.
17. Plato had treated any discussion of up and down in infinite space as nonsense . See Plato Timaeus 62d.