This paper was presented at Sources of Information Content in DNA, an Interdisciplinary Conference in Tacoma, Washington, June 23-26, 1988. It was revised July 30, 1988, and revised a second time May 6, 1991.
In antiquity intelligent causes were considered essential for understanding nature. Three centuries after the publication of Newton's Principia, however, nature seems to have been swept clean of intelligent influence, except for that of human beings. The notion that intelligent causes might play a significant role in understanding any natural object seems both anachronistic and ludicrous today. Yet several scientists with considerable stature in the scientific community have made the bold conjecture that life itself might have had an intelligent origin.{1} {2} {3}
My own thoughts turned to consider intelligent causes for the origin of life in the spring of 1978 during the writing of an early draft of a manuscript reassessing origin of life experiments. I was much taken by the fact that the investigator's own intellectual prowess is required to produce an effective abiotic simulation, yet credit for the results of such experiments is given nature instead of the investigator. That line of reasoning eventually led to criteria for evaluating prebiotic simulation experiments, and these were included in a chapter in The Mystery of Life's Origin.{4} In addition I began to entertain thoughts that intelligent causes might play at least a limited role in the explanation of nature, and included a brief statement to that effect in the book's epilogue.
A prima facie case for an intelligent source of the information in the base sequences of primordial DNA was elaborated in a subsequent paper, "DNA, Design, and the Origin of Life."{5} The present paper reviews some of the historical background for considering the viability of intelligent causes in science. Along the way we will examine why intelligent causes were deemed essential in antiquity, why they were abandoned in the Newtonian era, and discuss the basis for assigning causes in science. It is observed that intelligent causes have never been banned from science. On the contrary, science will accept any cause, natural or intelligent, if affirmed by uniform sensory{6} experience. After the case for considering intelligent causes has been presented, the charge that this is another example of "metaphysics masquerading as science" will be considered.
In a perceptive study of medieval and early modern science, A. C. Crombie noted that "All discussions of scientific method must presuppose a philosophy of nature, a conception of the kinds of causes and principles the method will discover."{7} This is vividly illustrated by contrasting the Greek view of nature and resulting science, and the modern which burst on the European scene in the seventeenth century after several centuries of preparation.
The predominant Greek view pictured nature as a living organism imbued with attributes of divinity. Nature was considered eternal and self-existent, impregnated with final causes or divine purposes and as such was regarded as self revealing. These purposes had only to be apprehended by the mind, hence the significance placed on intuiting axioms and principles from which all particular truths could be derived by deductive reasoning.{8} It followed from this view that Greek knowledge of nature and reality rested on the authority of the "system builders": Euclid in geometry, Plato and Aristotle in philosophy, Galen in anatomy, Ptolemy in astronomy, etc. The Greeks' conception of nature and reality led them to distrust the senses. Therefore, Greek science of nature was never experimental. No role was given sensory experience other than demonstrating what was already known through reason. So, following in the footsteps of Plato, philosophers in the twelfth century taught "that the senses were deceitful and reason alone could give truth."{9}
The dominant view of nature in medieval Europe was essentially Greek, having been co-opted by the Church and adapted for Christian service. It offered no motivation to investigate nature by observation and experiment. To the Greeks and those who followed their teaching, reality was thought to consist of forms and essences, not material things. In a world where ideals subordinate material reality observing "what is" becomes less important than reasoning "what must be."
The medieval world picture inherited from the Greeks included a vast hierarchy of beings extending from the deity in the Empyrean heaven at the outer edge of the universe, through a graded series of angels inhabiting the ten concentric crystalline spheres surrounding the central earth. This great chain of being,{10} as it was called, extended downward to the levels of men, animals and plants on the earth itself which formed the system's cosmic center.
A sharp qualitative distinction separated the terrestrial and celestial domains of the universe. Not only were the two domains composed of different kinds of materials, they had different motions. The terrestrial environs consisted of earth, air, fire, and water, each with rectilinear motion (downward toward the center of the earth), which had a beginning and an end. The heavenly bodies (above the moon) were composed of a more perfect fifth essence, with eternal circular motion.
According to ancient mechanics, motion was maintained only as long as there was a constantly applied push. In the words of historian Butterfield, "A universe constructed on the mechanics of Aristotle had the door half-way open for spirits already.... Intelligence had to roll the planetary spheres around."{11}
Medieval Christians were attracted to this Greek picture of the world. An authority-based hierarchical system with God in his Empyrean above the moon was easy to visualize. The angels mentioned in the Bible could render service by pushing the planets around -- not a difficult job since celestial bodies were said to be made of very light and tenuous fifth essence.
The linchpin for this medieval cosmology was Aristotle's view of motion through a constantly applied mover. The intelligences and angels moving the planets were ad hoc inventions, added to satisfy Aristotle's mechanics.
There were those as early as the thirteenth century who wanted to "use their eyes to look at the world in a new way," but "devotion to the texts of Aristotle or Galen" proved a great barrier.{12} A particularly noteworthy example of this desire was Jean Buridan, a 'physicist' whose theory of impetus prefigured Newton's concept of force. Buridan said, "One does not find in the Bible that there are Intelligences charged to communicate to the celestial spheres their proper motions; it is permissible then to show that it is not necessary to suppose the existence of such Intelligences. One could say, in fact, that God, when he created the universe, set each of the celestial spheres in motion as it pleased him, impressing on each of them an impetus which has moved it ever since. God has therefore no longer to move these spheres, except in exerting a general influence similar to that by which he gives his concurrence to all phenomena. Thus he could rest on the seventh day from the work he had achieved, confiding to created things their mutual causes and effects."{13}
It took several more centuries to break the spell Aristotle had over the Western consciousness. For as Butterfield noted, "It was supremely difficult to escape from the Aristotelian doctrine [of motion] by merely observing things more closely... it required a different kind of thinking-cap, a transposition in the mind of the scientist himself."{14} (my emphasis).
"One outstanding fact about the Scientific Revolution is that its initial and in a sense most important stages were carried through before the invention of the new measuring instruments, the telescope and microscope, thermometer and accurate clock, which were later to become indispensable for getting the accurate and satisfactory answers to the questions that were to come to the forefront of science. In its initial stages, in fact, the Scienfific Revoution came about rather by a systematic change in intellectual outlook, in the type of question asked, than by an increase in technical equipment. Why such a revolution in methods of thought should have taken place is obscure. It was not simply a continuation of the increasing attention to observation and to the experimental and mathematical methods that had been going on since the 13th century.... It is not an adequate explanation to say that the new approach was simply the result of the work done on inductive logic and mathematical philosophy by the scholastic philosophers down to the 16th century or the result of the revival of Platonism in the 15th century. It cannot be attributed simply to the effect of the renewed interest in some hitherto poorly known Greek scientific texts, such as the work of Archimedes...."{15} (my emphasis).
What produced the "different kind of thinking-cap" (Butterfield) and "systematic change in intellectual outlook" (Crombie) that led so dramatically to the modern science of nature? Crombie describes the source of the new philosophy of nature as "obscure" in the portion quoted above. It seems less so, however, in more recent studies.{16} {17} {18} {19} {20} {21} Accumulating scholarship confirms Foster's analysis half a century ago that showed "The modern investigators of nature were the first to take seriously in their science the Christian doctrine of creation."{22} (my emphasis). Belief in a created nature provided the new philosophy of nature that lay implicit in the work of Bacon, Kepler, Galileo, Boyle, Newton, etc. as they laid the foundation for a new method of studying nature.
It must rate as one of the greatest ironies that belief in supernatural creation should have had anything to do with developing methods for exploring the natural world. Why should this be?, one may ask. The mystery disappears when it is remembered that "All discussions of scientific method must presuppose a philosophy of nature..."{23} It makes sense to use deductive logic to ferret out every particular truth from intuited first principles if reality is ideas, and truth is discovered only by the mind through reason. If, however, the essential Aristotelian view of the world is fundamentally flawed, and nature is created and contingent upon the will of the Creator, then a new method must be developed consistent with the new view of nature. Modern experimental science which highly values sensory experience is a legacy of this mutation in thought about nature. "The presuppositions," which came from Christianity, as Collingwood expressed it, "have as a matter of historical fact been the main or fundamental presuppositions of natural science ever since."{24}
Bacon maintained that finding new facts required new methods. He set out to reformulate scientific method to give the empirical, inductive method a more prominent place. Part of the genius of modern empirical science was precisely its use of recurring natural events to provide observable checks on hypotheses. No more would scientists content themselves with speculative reason unchecked by sensory experience.
Thomas Fowler, an early biographer of Fancis Bacon, said of him that "He stood like a prophet on the verge of the promised land, bidding men to leave without regret the desert [of Aristotelianism] that was behind them, and enter with joyfulness and hopefulness on the rich inheritance that was spread before them."{25} Bacon typified the repudiation of the past's reliance on the authority of the ancients, be it Aristotle or religious tradition, when knowledge of nature was the goal. Sensory experience had been found a new and more reliable authority to judge claims about nature's behavior. As Bacon said, "nature is only to be commanded by being obeyed."{26} Obedience to nature could only be achieved by the closest observation. Three grand centuries of modern science have resulted.
Early modern scientists viewed the inductive method as a tool for discovering natural causes at work in the world. Since they held an implicit assumption that the world originated in divine creation, they did not ask questions about where things came from. They asked only how things work. Science developed as a tool for finding out how the universe operates.
Since the empirical method of science depends upon recurrent patterns for the testing of hypotheses, it is suited only for the study of events that are lawful. The goal of empirical science was the discovery of order in an apparent chaos of phenomena. An intelligent cause (whether man, angel, or God) acts not by law but by choice; thus through lack of sensory experience it was agreed that intelligent causes have no place in explanations of the regularities in nature. If, however, experience of the senses affirmed an intelligent cause for regular events, it would find its place in empirical science.
Kepler was an early modern scientist who was caught in between two regimes of science, the ancient Pythagorean (animistic Aristotelian) and the modern. His works pioneered in the development of modern science, showing the value of depending on experience instead of authority, whether of a religious tradition, a holy book, or reason, to settle scientific questions. For example, Kepler once abandoned a thoroughly worked out theory of planetary motion because it disagreed with empirical observation by only eight minutes of arc in the orbit of Mars. Some have thought it was taking observation a bit too seriously. But Kepler was convinced the true picture of the heavens would agree with the observations, and entail physical causes. Therefore, Kepler noted, "since it was not permissible to ignore them, those eight minutes point the road to a complete reformation of astronomy."{27}
Kepler had been deeply influenced by the Pythagorean intellectual tradition, and he never completely broke with it. The Pythagorean influence on Kepler was more than just his reliance on their mathematical achievements. He viewed the planets themselves as intelligent beings moving on their own. Kepler wondered "whether the laws [of nature] are such, that they probably can be known to the planet."{28} He even referred to the "mind" of the planet.{29} Thus Kepler has been numbered among the Neo-Pythagoreans of the Renaissance. Kepler did not mean, however, that the planets exercised will, and could act on their own volition. Rather, the "mind" was more like a computerized homing device, which could calculate orbital positions, and maintain course, but could not alter the instructions of its mission. Kepler was a man in process, whose thought and vocabulary at the time of writing Mysterium Cosmographicum, his first book, was still significantly informed by the old animistic tradition of the Pythagoreans who believed the universe was a divine, living being.
Kepler shows how far he had moved away from this Pythagorean notion in a letter to Hewart (February 10, 1605), which he wrote a few years later near the completion of his Astronomia Nova, "My aim is to show that the heavenly machine is not a kind of divine, live being, but a kind of clockwork..."{30} He was quite jubilant over his discovery that "nearly all the manifold motions are caused by a most simple, magnetic, and material force, just as all motions of the clock are caused by a simple weight. And I also show how these physical causes are to be given numerical and geometrical expression."{31}
Since Kepler is at a pivotal position in the history of science, between the ancient and the modern, one of his biographers has described him as The Watershed.{32} Before Kepler the tradition of science had little use for empirical observation. After him science would be unthinkable without it.
In antiquity up through the middle ages to the onset of modern science it was common to think of intelligences as responsible for regular motion. Cicero, for example, in the first century B.C. records the Stoic view, "But the conscious intelligence of the stars is most evident from the order and regularity of their movement. For nothing can move in a measured and orderly way without the guidance of an intelligence in which there is nothing arbitrary, dubious or accidental."{33}
Regular motion suggested intelligent causes to ancient man, and to moderns natural causes? Yes. It is because ancients asserted causes out of their philosophy, and we moderns rely on uniform experience of the senses. By uniform experience we have learned to associate natural causes with regular motion.
Galileo was another pioneer of modern science who valued sensory experience in the acquisition of knowledge. In his Letter to Christina in 1615 Galileo argued that unlike some Bible scholars were known to do, "it is impossible for professors of the experimental sciences to change their opinions at will."{34} There is an empirical check on our ideas about nature. Therefore, recurrent nature provides a more sure authority for our views of nature than that derived from the various interpretations of Scripture. He was not opposed to the Bible. He felt strongly, however, that God did not intend that we abandon sensory experience, reason and intellect. Furthermore it was Galileo's view that "all of the verses of Scripture are not obliged to function as rigorously as every law of nature.{35}
Galileo's discovery of the laws of projectile motion, combining mathematics and experiment, was a lasting contribution to science. He could test his ideas about how balls roll down inclined planes, how pendulums swing, how objects behave in free fall, and how a cannon ball travels in a parabolic trajectory. The new view of motion was based on experience.
Newton was a giant in science, and like Bacon, Kepler, and Galileo before him he "came to the investigation of nature with presuppositions drawn from Christianity which colored his idea of nature."{36} Newton combined the work of his predecessors, especially that of Kepler,{37} with his own ingenius contributions to create a masterful synthesis. Today we rightfully honor Newton for his magnificent achievement. According to the new world picture massive bodies floated in space, moved about by the physical force of gravity. The same rules would suffice to explain planetary motion in the heavens or the fall of a leaf on earth. Gone was the ancient dichotomy of heavens and earth composed of different substances, and explained by different rules. Physical forces would operate everywhere in the universe.
The ancient view that planets moved by intelligent beings pushing them around in the heavens was an authority-based conception unsupported by any experience. It was therefore replaced by the new world picture.
The Copernican revolution in astronomy was much more than revision of Ptolemaic theory. It was part of a great anti-authoritarian movement, which emphasized sensory experience as the touchstone of truth about nature, both on the earth and in the heavens. No longer would someone's word, even that of the great philosopher Aristotle, or of the Bible, or a priest, or even that of Isaac Newton, be sufficient by itself.
How far science had come in its abandonment of authority in science is illustrated by a famous story involving Newton. Once he was faced with certain anomalies of heavenly motion. Newton's answer was that God simply reached in and adjusted the cosmic mechanism. Who would know better than the Creator how to fix the malfunctioning universe? But Laplace, nearly a century later, objected to this answer of authority, and supplied the solution based on experience and natural causes that had eluded Newton. The French emperor Napoleon heard about it, and summoned Laplace to see if the story were true that he had left God out of his astronomy. Laplace's reply was, "Sire, I have no need of that hypothesis."{38} This episode has been looked upon ever since as a great illutration of the failure of intelligent causes, and not merely God, as an explanation in science. The story has been recounted many times.
David Hume has had an enormous influence in philosophy and it has not been inconsiderable in science. Early scientists like Kepler, Galileo, Boyle, and Newton had relied on experience to assign natural causes, but had not analyzed their procedure. This great service was provided by Hume.
Hume showed the way we must know any cause in science, particularly when, because of time and space limitations, we are no longer able to observe the phenomenon in question. According to Hume, "all reasonings concerning matter of fact seem to be founded on the relation of Cause and Effect. By means of that relation alone we can go beyond the evidence of our memory and senses."{39} (emphasis his.) Hume calls conclusions based on uniform experience "proofs," "meaning such arguments from experience as leave no room for doubt or opposition."{40} (emphasis his.)
It is custom or habit that allows us to connect events together in our mind, said Hume, as when we have observed flame associated with heat or snow with cold. He says that "if flame or snow be presented anew to the senses, the mind is carried by custom to expect heat or cold."{41} "Custom, then, is the great guide of human life. It is that principle alone which renders our experience useful to us, and makes us expect, for the future, a similar train of events with those which have appeared in the past. Without the influence of custom, we should be entirely ignorant of every matter of fact beyond what is immediately present to the memory and senses."{42}
There is within the uniformity of cause and effect the basis for a method to work backward from effect to cause. Isaac Newton, for example, had reasoned this way. In his Optics Newton declared, "The main business of natural philosophy is to argue from phenomena... and to deduce causes from effects till we come to the very first cause, which certainly is not mechanical."{43} In the General Scholium of the Principia Newton did not hesitate to inform his readers that this non-mechanical first cause was "an intelligent and powerful Being,"{44} "the God of Israel."{45}
There is no question this answer satisfied the sensibilities of the age in which Newton lived. Yet to those who came later, imbued with Hume, and convinced that scientific views must be based on sensory experience, there seemed but one conclusion. Intelligent causes in science had failed once again. The failure had happened often enough that many had begun to suspect that intelligent causes were not viable at all in physical science.
Very often one's individual reservoir of experience is insufficient to identify the cause of some event as natural or intelligent. The prudent course is to follow the advice philosopher Wittgenstein gave in another context, "Whereof one cannot speak, thereof one must be silent."{46} A curious propensity afflicting many people, however, as the story above involving Newton illustrates, is to go ahead and name a cause anyway. The "cause" is almost always put forth out of their philosophy or religion. Sometimes they are later shown correct, and are hailed for their sagacity and foresight. However, it was only a wish or a guess, even though it may have been given with all the assurance and confidence of an eyewitness. At other times they are wrong. In both cases their foolish assertion without experiential basis serves as an obstacle to knowledge about nature.
Even though both natural and intelligent causes are known to us by experience, the modern empirical science of nature typically acknowledges only natural causes. Is this prejudice on the part of scientists, some kind of conspiracy to ban intelligent causes? Not in the least. Science will allow any cause, natural or intelligent, for which there is uniform sensory experience. In the history of modern science, however, uniform experience has associated only natural causes with regular events. That is why we do not include intelligent causes in the science of regularities today. It is not a ban, however. If intelligent causes were associated with regular events they would be allowed in science.
In lieu of uniform experience we are unjustified in positing a cause, natural or intelligent, for any phenomenon. To illustrate, suppose we are detectives investigating a person's death. Is this a case of murder or did the person die of natural causes? We cannot know the answer in advance. We have to look and find out. If a detective announced at the beginning of his investigation that the person's death could only have been natural, we would object that this was an illegitimate restriction of the possible causes.
Since what we hope to discover through our investigation is precisely whether death resulted from an intelligent cause (murder) or was natural, we need a method of inquiry open to either explanation. In the same way, those genuinely seeking to discover whether an event in nature is the result of intellect or of natural causes need a method of inquiry open to either explanation. A method is needed that will enable us to determine with the highest probability which it was.
As we have seen, regularities have throughout the history of experimental science been associated with natural causes. Other events, most notably origin events, are not regular, and may be unique. What we need is a methodology that will get beyond a priori commitment to causes and give us criteria for building a case for either natural or intelligent cause.
How would one decide in favor of an intelligent cause of some event in the past? In general we use the same method to identify an intelligent cause that we use for a natural cause, i.e., uniform sensory experience. It is called the analogical method.
In the 19th Century the astronomer John F. W. Herschel advanced the analogical method of reasoning from observed causes to unknown causes: "If the analogy of two phenomena be very close and striking, while, at the same time, the cause of one is very obvious, it becomes scarcely possible to refuse to admit the action of an analogous cause in the other, though not so obvious in itself."{47} (emphasis added) Scientists have relied on this method for more than 150 years. The tremendous success of science is at least a partial attestation of the method. This analogical method of assigning causes was also significant in the landmark work of Charles Lyell, and became enshrined in geological literature as "the present is a key to the past."{48} We have learned by experience to associate a particular type of effect with a certain kind of cause. Therefore, upon seeing a similar effect we routinely and automatically identify the same kind of cause. The judgment comes from our accumulated reservoir of experience. The method is quite general and is used for identifying either natural or intelligent causes.
As an illustration of the anological method, consider the field of archaeology. The principle of analogy is used regularly in archaeology to determine whether some finding or other had an intelligent cause. The reasoning goes like this: In the present we see craftsmen making pottery. Therefore, when we search through the dust in a tell in Mesopotamia and find a broken clay pot, it is reasonable to infer that its source was likewise a craftsman. Archaeologists used the same logic the first time they came upon pyramids. The stones of which they were made were like other stones they knew to be shaped by stone-cutters. Only the overall structure of the pyramids was new to Europeans. Thus it was decided these were the work of artisans, and not of natural processes.
It was once thought there were canals on Mars. This led to speculation that there was intelligent life on the planet. Although it turns out the idea was mistaken, it again illustrates the reasoning we all use: when we see certain kinds of effects, we infer intelligent causes, based on the principle of analogy.
This is also, incidentally, the reasoning employed by astronomers in their search for intelligent life in the cosmos. It is routinely used by NASA imaging teams to evaluate data from planets and their moons: these teams use criteria for recognizing evidence of intelligent life on the planets -- some distinctive mark of things produced by intelligence. Over the years there have been various attempts to Search for Extra-Terrestrial Intelligence, which has been given the acronym SETI. One such program is Project Sentinel which is the major SETI project of The Planetary Society.{49},{50} In its expanded version called Project META (Megachannel Extraterrestrial Assay) it has the capacity to survey more than eight million radio channels for possible radio signals from space.{51}
Astronomer Carl Sagan has maintained that even a single message from space would establish the existence of extraterrestrial intelligences. He wrote:
There are others who believe that our problems are soluble, that humanity is still in its childhood, that one day soon we will grow up. The receipt of a single message from space would show that it is possible to live through such technological adolescence: the transmitting civilization, after all, has survived.{52} (emphasis added)
If scientists do detect radio waves from space, how will they decide whether they constitute a message or not? This question is explored in Carl Sagan's fictional tale Contact. Sagan reminds us that though our planet is bathed continuously with radio emissions, they are all natural. Such emissions are "caused by physical processes, electrons spiralling in the galactic magnetic field, or interstellar molecules colliding with one another, or the remote echoes of the Big Bang red-shifted from gamma rays at the origin of the universe, to the tame and chill radio waves that fill all of space in our epoch".{53} So far "there has never been a real signal from the depths of space, something manufactured, something artificial, something contrived by an alien mind."{54}
As it turns out, detecting a real message might not be so easy. According to Claude Shannon's famous theorem in information theory the most efficiently coded message is indistinguishable from noise, unless one already possesses the key to the encoding. However, that leaves room for less efficiently coded messages. As in Sagan's novel, we may discern an alien intelligence by detecting something very artificial, very specific like a sequence of prime numbers, i.e., numbers which are not divisible except by themselves and the number one. Such a message of prime numbers might be merely to get our attention, and a more informative communication would conceivably follow. Then with something like a Galactic "Rosetta Stone" we would be able to decrypt a message received from an alien intelligence. Without it we most probably would never know what the message contained.
As in the case of Egyptian hieroglyphics, however, we may still suspect certain markings (signals) represent a message before the decryption key is found which confirms it. Because real messages are usually encoded with less than perfect efficiency some cryptologists believe "it is possible to know that a signal is of intelligent origin without decoding the message it contains."{55} If we do discover radio waves that exhibit the characteristsics of a message, would we not be justified in positing an intelligent being as their source, based on analogy with the messages we know in our experience are produced by intelligent beings, namely humans? In other words, the analogical method would detect generic intelligence, not specifically human intelligence.
Transferring this reasoning to the question of origins, we want to know whether a particular origin event resulted by natural or intelligent causes. We examine the effect, the product of the origin event, and ask if there are the characteristic signs of natural or intelligent cause that we have learned from our experience. Does this object we are trying to explain fit the pattern we know by experience is the product of intelligent manufacture? If so then we assign an intelligent cause. If it fits the pattern our reservoir of experience shows results from natural causes, then we assign a natural cause. Otherwise we say we don't know the cause.
The principle of analogy requires only that the cause observed in the present is similar in kind to the cause posited for the past. For instance, one does not have to find life arising spontaneously from non-living materials in the present in order to posit that it did so in the past. All that is necessary for a plausible natural cause scenario is to point to similar instances where some characteristic feature of life, such as DNA or some other informational molecule, is produced naturally (which is a major goal of laboratory simulation experiments). Likewise, for a plausible intelligent cause scenario one does not have to catch "red-handed" an intellect operating in the present that is identical to the one posited in the past. All that is necessary is to observe similar kinds of intelligent causes that regularly produce some characteristic feature of life.{56} How does one conclude the cause is similar? By whether the effects are "very close and striking." (Herschel).
The intelligent cause observable to us today is, obviously, human. But other forms of intelligence may also be posited. In working backward from effect to cause, the inferred intelligence is generic, i.e., it could theoretically be of this earth, or off the earth. Scientists involved in the Search for Extraterrestrial Intelligence program are not required to posit a human intelligence beaming radio messages from space. On the basis of analogy, we only need to posit one similar to humans. If we posit an intelligent cause for the origin of life, it cannot be a human intelligence, because humans did not yet exist. Nevertheless, if a plausible case can be constructed for it, we may posit a similar intelligent cause.
Is there any basis in experience for an intelligent cause for the origin of life? Yes! It is the analogy between the base sequences in DNA and alphabetical letter sequences in a book. Since the analogy has been discussed at length elsewhere, it will not be elaborated here.{57} I will point out, however, that the analogy is "very close and striking," (Herschel) so close in fact because there is a structural identity between the DNA message sequence and a written message.{58}
If the inference of an intelligent cause for DNA (and life too, if it is truly necessary for life) is in error, then we would likewise be in error to infer the presence of extraterrestrial intelligence upon receipt of intelligible radio messages from deep space. More importantly, our knowledge of past civilizations provided by archeologists would be in jeopardy. These supposed "artifacts" might be, after all, the result of unknown natural causes. Cave paintings, for example, dated at 12,000 BC may not be the result of early man at all. Clay figures of animals and man dated from 30,000 BC may have had natural causes. Truly immense consequences follow if we doubt the inference of an intelligent source for the information in DNA. Indeed uncovered ancient libraries could not be trusted to contain the works of intelligent men and women.
The principle of analogy, we repeat, is simply a different way of stating the principle of uniformity, that the causes we posit for past events must be similar to causes we see in the present.
The philosopher David Hume gave an eloquent defense of the principle of uniformity, which is usually interpreted as leading to a naturalistic philosophical conclusion. Indeed Hume did say, for example, "There must, therefore, be a uniform experience against every miraculous event."{59} He opposed arguments based on religious authority, believing that uniform experience was the true path to knowledge. Hume substituted experience for other forms of authority. Uniform experience meant that "From causes which appear similar we expect similar effects."{60} (emphasis in original). Hume, however, made it clear he was not restricting himself to natural causes when he later added, "the same rule holds, whether the cause assigned be brute unconscious matter, or a rational intelligent being."{61} Hume was not opposed to an intelligent cause supported by uniform experience. Indeed he laid the foundation for its use. Hume argued we cannot infer deity from uniform experience.
Hume elaborated on the legitimacy of inferring intelligent causes in a famous passage in his Dialogues Concerning Natural Religion. Cleanthes, one of Hume's characters, says:
Look around the world: contemplate the whole and every part of it: you will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines, which again admit of subdivisions, to a degree beyond what human senses and faculties can trace and explain. All these various machines, and even their most minute parts, are adjustsed to each other with an accuracy, which ravishes into admiration all men, who have ever contemplated them. The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the productions of human ... intelligence. Since therefore the effects resemble each other, we are led to infer... that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of man; though possessed of much larger faculties, proportioned to the grandeur of the work, which he has executed."{62}
(emphasis added.)
Many have supposed Cleanthes represented Hume's own views. If so he harbored private beliefs about an intelligent origin. There is no other hint in the body of Hume's works that he believed it. For this reason many scholars claim Cleanthes does not represent Hume. At any rate Hume gave us the reasoning for assigning past causes, whether natural or intelligent, by uniform experience. All historical sciences use it under the name of the principle of uniformity, or the analogy principle.
Interestingly, the argument from design, the most popular and most empirical argument for creation in the nineteenth century,{63} is actually based on Hume's principle of uniformity. The design argument is best known in its formulation by William Paley in 1802.{64} Piling fact upon fact, Paley described the intricate marvels and adaptations found in living things. Ascribing these to natural causes, his famous argument goes, is like finding a watch in an open field and declaring it the result of natural causes. As the watch requires a watchmaker, so the world requires a creator, a divine Watchmaker. Paley may even have gotten this watchmaker illustration from Hume who said, "A man finding a watch or any other machine in a desert island, would conclude that there had once been men in that island. All our reasonings concerning fact are of the same nature."{65}
Paley demonstrated that the structure of Hume's argument could support the conclusion of an intelligent cause just as well as it supported the conclusion of a natural cause. Using Hume's own phrases, "constant conjunction," and "uniform experience," Paley argued that, "Wherever we see marks of contrivance, we are led for its cause to an intelligent author."{66} This conclusion "is founded upon uniform experience."{67} How so? Because "we see intelligence constantly producing effects" (constant conjunction).{68} Paley concludes:
We see, wherever we are witnesses to the actual formation of things, nothing except intelligence producing effects so marked and distinguished in the same manner. We wish to account for their origin. Our experience suggests a cause perfectly adequate to this account. No experience, no single instance or example, can be offered in favor of any other. In this cause, therefore, we ought to rest; in this cause the common sense of mankind has, in fact, rested, because it agrees with that which in all cases is the foundation of knowledge --the undeviating course of their experience.{69} (emphasis added)
Hume did not refute Paley's design argument in advance. Instead, Paley used Hume's argument, the appeal to uniform experience, to argue for an intelligent source of life and the universe. Paley did make a fatal mistake, however. Like Newton before him, Paley named the intelligent cause as God without a sensory basis. To him it was philosophically necessary. Thus Paley's contribution is correctly labeled natural theology instead of natural science.
Throughout the history of modern science there has been a very great temptation to discuss origin questions in metaphysical terms, instead of scientific. Newton and Paley, for example, as already discussed, both weakened their case for a strictly scientific view of origins by offering their insights commingled with metaphysics. In effect their metaphysics, at this point, masqueraded as science.
Because of theistic presuppositions held by many scientists, particularly in the emergent early phase of experimental science, it is not surprising to see numerous religious references in their writings. Similarly, it is not uncommon to see expressions of metaphysical naturalism in science writing today. They are a quite human manifestation of one's implicit thought pattern. Even so, such expressions of philosophy and religion are not science and must be judiciously avoided in strictly scientific contributions.
Undoubtedly because modern science was born and nurtured in a theistic culture, a genre of literature arose showing the connection between science and traditional religious beliefs. This became known as natural theology, and formed a symmetry with natural philosophy, as science was first called.
As the years passed the great success of experimental science in providing natural cause answers to many mysteries had a mesmerizing effect. Satisfied that uniform sensory experience affirmed natural causes, but not the supernatural, many began to restrict science to natural causes alone. This, however, betrays a confusion between scientific and metaphysical categories, which needs to be both corrected and avoided.
Consider the diagram below, which shows the proper alternative to a natural cause in science is intelligent, not supernatural.
| Scientific | Metaphysical |
| natural / intelligent | Natural / Supernatural |
The proper basis for assigning causes in science is sensory experience. Experience distinguishes natural and intelligent causes, as in the case of ripples on a beach versus writing in the sand. As elementary and self evident as this distinction is, the intellectual tradition which informs much of our education has embraced the philosophical terminology expressed in the dichotomy Natural / Supernatural. When students are told, for example, that the public school science classroom is not the appropriate forum for discussing the supernatural, without any mention of the intelligent cause possibility, it does not require brilliant students to conclude that what is being offered is Naturalism. This conclusion follows from the twin messages:
1. science includes only natural causes;
2. science does not include the supernatural.
Confusion between science and metaphysics arises from the use of the equivocal term natural.{70} Unless care is taken by both author and reader, or speaker and listener, we run the risk of using natural in both a scientific and a metaphysical sense. Consider two examples of this confusion among many that could be cited:
Example 1 Leslie Orgel: "...any 'living' system must come into existence either as a consequence of a long evolutionary process or a miracle."{71}
Example 2 Paul Davies: "The origin of life remains one of the great scientific mysteries.... The problem is to understand how this threshold could have been crossed by ordinary physical and chemical processes without the help of some supernatural agency."{72}
Both of these examples mix the categories of science and metaphysics. Clearly what these authors intended to say was that the supernatural may not be brought into science, as indeed it may not.{73} Failure to include intelligent cause as the proper scientific alternative to a natural cause, however, transforms these quotes into metaphysical statements affirming philosophical materialism.
When one says that a cause must be natural it advances materialism because it ignores the possibility of intelligent cause, even if all the author meant was that in science, where we are limited to sensory experience, one may not affirm a cause as supernatural. Sensory experience is simply blind to the metaphysical categories, Naturalism and Supernaturalism.
When a text or a teacher are given entirely to natural cause explanations, holding that science may include only natural causes, it entails a presumption of Naturalism. The science classroom is not the proper forum to introduce either Naturalism or Supernaturalism.
Affirming natural causes as the probable source for the origin of life, for example, does not necessarily mean Naturalism. For how does one know from experience that some higher power or intellect (God?) does not stand behind the scenes, guiding the natural process? Since we do not know the answer, we remain equivocal on the matter of cause. Therefore, we may not infer from experience the metaphysical conclusion of Naturalism. According to Ian Barbour, "Naturalism is still a live option, but it is clear that it must be defended as a philosophical viewpoint and not a conclusion of science."{74} Likewise when one infers an intelligent cause of DNA (life?) by experience, it does not carry the necessary conclusion of Supernaturalism. By experience we cannot determine whether the inferred intelligent cause is within the universe (Naturalism) or beyond it (Supernaturalism).
The diagram below portrays both a natural cause and an intelligent cause view for both ultimate metaphysical categories, i.e., supernaturalism and naturalism:
|
|
Intelligent |
|
|
|
|
|
1 |
|
2 |
|
|
Supernaturalism |
|
|
|
Naturalism |
|
|
3 |
|
4 |
|
|
|
|
Natural |
|
|
Four fundamental metaphysical viewpoints on origins:
1) Supernaturalistic creation = intelligent cause supernaturalism
2) Naturalistic creation = intelligent cause naturalism
3) Supernaturalistic evolution = natural cause supernaturalism
4) Naturalistic evolution = natural cause naturalism
Such a diagram can be drawn for considering the possible metaphysical viewpoints for each origin question, i.e., the origin of the universe, the origin of life, the origin of species, the origin of man, etc.
Anyone who advocates one of these four views for a particular origin question is doing apologetics, not science. Likewise if one argues for either Supernaturalism or Naturalism without regard to whether the cause is natural or intelligent, it is also apologetics. In other words, there are a lot of ways to slip into the metaphysical mire. It requires great care to remain within the legitimate borders of empirical science.
Although science is more than a search for causes, determining causes is an important part of science. One stays within science by affirming causes, natural or intelligent, on the basis of experience, without regard to metaphysical category. Furthermore, we must refrain from assigning causes when experience is lacking. There must be positive evidence for assigning a cause of some phenomenon. It is not enough to marshal a case against a cause, and then assert the cause of one's preference. Many have been misled for a time when in lieu of experience they allowed themselves to become mesmerized by a hypothetical cause which was only a cover for their ignorance.
The question of why intelligent causes were considered essential in antiquity was examined, and we concluded it was out of philosophical necessity to satisfy the Aristotelian view of motion. The birth of modern experimental science involved a shift in philosophy about nature. The result was a transition from seeing no essential role for sensory experience in the acquisition of knowledge about nature to seeing experience as vital.
The view that intelligences roll the quintessential planets around in the heavens was replaced by one that sees the planets as physical objects moved by physical forces. Abandonment of intelligent causes was due to lack of uniform sensory experience.
Uniform experience of the senses is the guide for assigning causes in science. Science will allow any cause, natural or intelligent, if it is supported by uniform experience. We have shown therefore that science is not restricted to natural causes and we point out that intelligent causes have never been banned from science. Such a restriction would eliminate archeology and SETI, for example, from the ranks of science.
We considered what is involved when one's metaphysics masquerades as science and what steps are required to correct and avoid it. In brief, the proper scientific alternative to a natural cause is intelligent, not supernatural. The generic nature of both natural and intelligent causes is what allows one to do science instead of metaphysics when assigning causes by experience. When one goes beyond experience to declare a particular metaphysical position, it is apologetics. Although apologetics is a legitimate and quite human activity, it is not science.
The designation "intelligent cause" is generic, i.e., metaphysically equivocal, and until specified more fully we cannot say whether it is within or beyond the universe. Furtheremore, uniform experience cannot resolve this fundamental ambiguity. Therefore, an inferred intelligent cause is not necessarily Supernaturalistic.
The designation "natural cause" is also generic, i.e., metaphysically equivocal. Sensory experience cannot inform us as to whether the natural cause of some phenomenon is all there is or whether there might be a higher power or intellect controlling it from behind. Therefore a natural cause is not necessarily Naturalistic.
We conclude therefore that intelligent causes are a viable option today for science, and the determining factor for whether we affirm intelligent causes in any scientific discipline rests with whether there is uniform experience by which to make a valid inference.
{1}Fred Hoyle and Chandra Wickramasinghe, 1981. Evolution From Space, A Theory of Cosmic Creationism. New York: Simon and Schuster.
{2}Fred Hoyle, 1983. The Intelligent Universe. New York: Holt, Rinehart and Winston.
{3}Francis Crick, 1981. Life Itself. New York: Simon and Schuster. To be accurate Crick does not say life resulted from intelligent causes. He merely says life may have been sent here from somewhere else by intelligent beings. He is silent about the cause.
{4}C. Thaxton, W. Bradley, and R. Olsen, 1984. The Mystery of Life's Origin. New York: Philosophical Library.
{5}C. Thaxton. "DNA, Design, and the Origin of Life." Truth, (to be published) Dallas, TX: Truth, Inc.
{6}David Hume introduced the phrase "uniform experience." By this he meant what I mean by uniform sensory experience, an objective experience of the five senses, not a subjective or a religious experience.
{7}A. C. Crombie, 1967. Medieval and Early Modern Science. vol. II, Cambridge, MA: Harvard University Press, p. 13.
{8}ibid., p. 3.
{9}ibid., p. 4.
{10}Arthur O. Lovejoy, 1960, [1936]. The Great Chain of Being. New York: Harper & Row Publishers.
{11}Herbert Butterfield, The Origin of Modern Science, 1957. New York: The Free Press, p. 62.
{12}Crombie, ibid., p. 106.
{13}Jean Buridan, cited in A. C. Crombie, ibid. p. 69.
{14}. ibid., pp.16,17.
{15}Crombie, ibid., p. 122.
{16}Stanley L. Jaki, 1974. Science and Creation: From Eternal Cycles to an Oscillating Universe. Edinburgh: Scottish Academic Press.
{17}Stanley L. Jaki, 1978. The Road of Science and the Ways to God. The Gifford Lectures 1974-75 and 1975-76, Chicago: The University of Chicago Press.
{18}Stanley L. Jaki, 1979. The Origin of Science and the Science of its Origin. South Bend, Indiana: Regnery/Gateway.
{19}R. Hooykaas, 1972. Religion and the Rise of Modern Science. Grand Rapids, Michigan: Wm. Eerdmans.
{20}Eugene M. Klaaren, 1977. Religious Origins of Modern Science. Grand Rapids, Michigan: Wm. Eerdmans.
{21}Thomas F. Torrance, 1975, [1965]. "The Influence of Reformed Theology on the Development of Scientific Method," in Theology in Reconstruction. Grand Rapids, Michigan: Wm. Eerndmans.
{22}M. B. Foster, 1934. "The Christian Doctrine of Creation and the Rise of Modern Science." Mind 43, p. 448.
{23}Crombie, ibid., p. 13.
{24}R. G. Collingwood, 1972. Essays on Metaphysics. Chicago: Henry Regnery Company, p. 227.
{25}Thomas Fowler, cited in The Encyclopedia of Philosophy, 1967. New York: Macmillan & The Free Press, Paul Edwards, Editor in Chief, Volume 1, p. 239. Article on Francis Bacon.
{26}Francis Bacon, Novum Organum, Book I, Aphorism 129, in The Works of Francis Bacon, 1842. Philadelphia: Carey and Hart, Volume 3, p. 370.
{27}Johannes Kepler, quotation in Arthur Koestler, The Watershed: A Biography of Johannes Kepler, 1960. New York: Anchor Books, p. 134.
{28}Johannes Kepler, Astronomia Nova, cap. 57 (Opera III, 392-397). Cf. ibid. cap. 39 pp. 317-320.
{29}ibid.
{30}Johannes Kepler, letter to Hewart, cited by Arthur Koestler in his The Watershed, Garden City, NY: Anchor, 1960, p. 155.
{31}ibid.
{32}Arthur Koestler, The Watershed, 1960. Garden City, NY: Anchor Books.
{33}Cicero, 1972. The Nature of the Gods. Translated by Horace C. P. McGregor, with an introduction by J. M. Ross. Harmondsworth, Middlesex, England: Penguin Books, p. 140.
{34}Galileo Galilei, Letter to Christina, 1615, published in The Works of Galileo Galilei, 1965, Florence: G. Barbera, vol. 5, p. 17.
{35}ibid., p. 8.
{36}Richard S. Westfall, 1973. Science and Religion in Seventeenth Century England. Ann Arbor, MI: University of Michigan Press, p. 198.
{37}In a letter dated July 14,1685, Isaac Newton wrote, "I gathered it [key insight concerning gravity] from Kepler's theories about twenty years ago." Quotation in Gerald Holton, Thematic Origins of Scientific Thought, 1973. Cambridge, MA: Harvard University Press, p. 89.
{38}Simon Laplace, cited in E. T. Bell, 1937. Men of Mathematics. New York: Simon and Schuster, p. 181.
{39}David Hume, An Inquiry Concerning Human Understanding, 1748, [1952]. Chicago: Great Books of the Western World, R. M. Hutchins, editor in chief, Section IV, Part I, Paragraph 22, p. 458.
{40}ibid., Section VI, footnote, p. 469.
{41}ibid., Section V, Part I, p. 466.
{42}ibid., Section V, Part I, p. 465.
{43}Isaac Newton, 1717, [1952]. Optics. 2nd. edition. Chicago: Great Books of the Western World, R. M. Hutchins, editor in chief, Book III, Part I, pp. 528-529.
{44}Isaac Newton, 1725, [1952]. Principia, translated as Mathematical Principles of Natural Philosophy, 3rd edition. Chicago: Great Books of the Western World, R. M. Hutchins, editor in chief, Book III, General Scholium, p. 369.
{45}ibid., p. 370.
{46}Ludwig Wittgenstein, The Tractatus.
{47}John F. W. Herschel, 1831. Preliminary Discourse on the Study of Natural Philosophy. London: Longman, Rees, Orme, Brown, and Green, p. 149.
{48}Charles Lyell, [1830] 1887. Principles of Geology, Vol. I, New York: D. Appleton and Company. Nowhere have I found this quotation that is usually attributed to Lyell in any of his writings. However, Lyell did say in the Principles that knowledge of the present processes of nature is "a key to the interpretation of some mysteries in the past." p. 319.
{49}Thomas R. McDonough, "Project Sentinel to Grow," The Planetary Report, Volume 4, Number 1, January/February 1984, p.3.
{50}Paul Horowitz, "A Status Report on The Planetary Society's SETI Project," The Planetary Report, Volume 7, Number 4, July/August 1987, pp. 8-10.
{51}Paul Horowitz, "SETI and The Planetary Society," The Planetary Report, Volume 6, Number 1, January/February 1986, p. 17.
{52}Carl Sagan, Broca's Brain, 1979. New York: Random House, p. 275
{53}Carl Sagan, Contact, 1985. New York: Simon & Schuster, p. 51.
{54}ibid., p. 51.
{55}Edward Regis, Jr. "SETI Debunked," in Extraterrestrials, Editor, Edward Regis, Jr.,1985. Cambridge: Cambridge University Press, p. 236.
{56}A. David Kline, "Theories, Facts, and Gods: Philosophical Aspects of the Creation-Evolution Controversy," in Did the Devil Make Darwin Do It?, ed. David B. Wilson, 1983. Ames, Iowa: Iowa State University Press, pp. 37-44. Kline points out that "even when instances of a regularity are observable... one cannot repeatedly observe the same events being instances of the regularity simply because every event is unique. No event occurs twice.... Of course, given some notion of relevant similarity, relevantly similar events can occur an indefinitely large number of times. It is by observing such event types that scientists confirm observational laws." (emphasis in original.), p. 40.
{57}See references 4 (epilogue) and 5
{58}Hubert P. Yockey, 1981. "Self Organization Origin of Life Scenarios and Information Theory," J. Theoret. Biol. 91, 13. "It is important to understand that we are not reasoning by analogy. The sequence hypothesis [that the exact order of symbols records the information] applies directly to the protein and the genetic text as well as to written language and therefore the treatment is mathematically identical." The structural identity between DNA and a written message is the basis for identical mathematical treatment.
{59}David Hume, An Enquiry Concerning Human Understanding, [1748], 1952. Chicago: Great Books of the Western World. R.M. Hutchins, ed., p. 491.
{60}ibid., p. 462.
{61}ibid., p. 499.
{62}David Hume, Dialogues Concerning Natural Religion, p. 30.
{63}Frederick Ferre, 1973. "Design Argument," Dictionary of the History of Ideas, Vol. I., New York: Charles Scribner's Sons, p. 673.
{64}William Paley, [1802] 1963. Natural Theology. Editor, Frederick Ferre. New York: Bobbs-Merrill.
{65}Hume, Enquiry, Section IV, Part I, Paragraph 22, p. 458.
{66}Paley, ibid., p. 37.
{67}ibid.
{68}ibid.
{69}ibid.
{70}My point is that much confusion and miscommunication has been promoted by the use of the term natural because of the ambiguity created by using it in both a scientific and a philosophical sense. It is similar to the effects created in the mind by the words see and saw in the following conundrum: I see, said the blind carpenter as he picked up his hammer and saw. With each word the mind is confronted with two meanings, which is what I mean in calling "natural" an equivocal term.
{71}Leslie Orgel, 1973. The Origins of Life. New York: John Wiley, p. 192.
{72}Paul Davies, 1983. God and the New Physics, New York: Simon and Schuster, p. 68.
{73}Even here we must be clear concerning the reason why. In science we may bring in only causes affirmed by uniform sensory experience. Until such time as there is uniform experience that some phenomenon has or had a supernatural cause, we may not properly include it in a scientific description.
{74}Ian G. Barbour, 1960. In Science Ponders Religion, New York: Appleton-Century-Crofts, p. 200.
© 1991 by Charles B. Thaxton