Epistemology. It’s What You Know
|January 7, 2008||Posted by Barry Arrington under Intelligent Design|
BarryA’s definition of a philosopher: A bearded guy in a tweed jacket and Birkenstocks who writes long books explaining how it is impossible to communicate through language without apparently realizing the irony of expressing that idea through, well, language.
Seriously, I have read a lot of philosophy, and I find some of the philosophers’ ideas valuable (that is, when I can decipher them though the almost impenetrable thicket of jargon in which they are usually expressed). In particular, epistemology (the theory of what we know and how we know it) is one of the most useful philosophical ideas for the ID – Darwinism debate. Indeed, many of the discussions on this blog turn on questions of epistemology. So I thought it would be helpful to give a brief overview of the subject in the ID context. So here goes –
Consider the following statement one often hears: “We can be as certain that the diversity and complexity of living things arose by chance and necessity through blind watchmaker Darwinism (BWD) as we are that the earth orbits the sun.”
To examine this statement, we must first understand what it means to “know” something, and this is where epistemology comes in. The standard philosophical definition of knowledge is “justified true belief.” Why not just “true belief”? Because if we have no basis for our belief, the fact that our belief might in fact be true would be a mere coincidence. We cannot, therefore, say we know something unless we have evidence to support our belief; in other words, the belief is justified.
Keep in mind that our beliefs can never be justified in an absolute sense. You have a justified belief that you are sitting at your computer reading this scintillating post. Even though this belief is highly justified and almost certainly true, you cannot rule out that you are dreaming or that you are in the Matrix or that you have been deceived by one of Descartes’ demons.
A corollary to the proposition that beliefs can never be absolutely justified is that justification is always relative. Indeed, these are two ways of saying the same thing. Thus, justification of our beliefs comes in degrees; some beliefs are more justified than others. About some beliefs we can be all but certain they are true. While there is some remote possibility you are in the Matrix and not actually reading this post, for all practical purposes we can discount the Matrix possibility and conclude that your belief is true.
It is interesting to note that the Matrix idea is not new. In the 1700’s George Berkeley (after whom the California city and university are named) proposed that an individual cannot know that an object “is.” He can only know that he has a “perception” that there is an object. In his “Life of Johnson” Boswell records Dr. Johnson’s response to Berkeley:
“After we came out of the church, we stood talking for some time together of Bishop Berkeley’s ingenious sophistry to prove the nonexistence of matter, and that every thing in the universe is merely ideal. I observed, that though we are satisfied his doctrine is not true, it is impossible to refute it. I never shall forget the alacrity with which Johnson answered, striking his foot with mighty force against a large stone, till he rebounded from it – ‘I refute it thus.’”
At one level Boswell was right and Johnson was wrong. As a matter of pure logic, Berkeley’s ideas are irrefutable. Berkeley would have replied that when Johnson kicked the stone, all he could be certain of was that he had a perception in his mind that he kicked a stone. He could not be absolutely certain that he had in fact kicked a stone. Nevertheless, Johnson’s main point is valid. Our sensory experience of the outside world is all we have. If we doubt that experience, we are left in a hopeless mire of doubt and skepticism. Therefore, while we can never be certain that Berkeley was wrong, as a practical matter, in order to live our lives and make progress in science, we can safely ignore him.
It is beyond the scope of this post to discuss philosophical hyper-skepticism in detail. For my present purposes, I will note that even hyper-skeptics look both ways when they cross the street. In other words, while hyper-skepticism may be interesting to discuss in the parlor on Sunday afternoon after lunch, it is perhaps the least practically helpful idea in all of philosophy. For the scientific enterprise (and life generally) hyper-skepticism may be dismissed with a nod.
In summary, therefore, we can trust our sense impressions to give us generally reliable information about the world upon which to base our scientific conclusions. For my purposes here, “sense impressions” include both direct impressions on our senses and impressions from various measuring instruments such as telescopes and microscopes. Moreover, science has a check against conclusions based upon erroneous sense impressions. All scientific observations must be “inter-subjectively” testable. In other words – as the scientists who announced they had achieved cold fusion a few years ago found to their dismay – scientific conclusions are not usually accepted until other scientists replicate the results in independent experiments.
Having slain the dragon of hyper-skepticism (or at least banished him to his cave like the bad boy he is), we move on to the practical business of scientific discovery. This method is familiar to most of us. In truncated summary the model is:
1. Think of a question that needs to be answered.
2. Formulate a hypothesis to answer the question.
3. Test the hypothesis by experiment and/or observation.
Here is where the concept of “fact” comes in. In philosophy, a “fact” is a state of affairs described by a true proposition. In science we say that a “fact” is an objective and verifiable observation. I have a hammer in my office (I don’t know why, but I really do). Just now I picked up the hammer, held it above the floor, and dropped it. The following is a statement of fact. “It is a fact that Barry’s hammer fell to the floor when he dropped it.” In science we have a epistemic hierarchy:
1. Facts: The raw objective and verifiable observations. Of the correspondence between truth and proposition, this is where we have the most confidence. Unless I’m in the Matrix (a possibility we have decided to ignore), it cannot reasonably be disputed that my hammer really did drop to the floor.
2. Hypothesis: An explanation for a phenomenon that can be tested.
3. Theory: A coherent model that gives a general explanation of observed data.
About facts, we can be certain, but our conclusions based on those facts (our theories) are less certain. In fact, some of our most cherished beliefs can turn out to be untrue even though they were highly justified and seemed to correspond to the data perfectly.
Ptolemy’s cosmology is a perfect example. Ptolemy, who lived from about 83 to 161 AD, was the greatest of the ancient astronomers. It is a modern conceit that the ancients were quaint simpletons who thought we live in a cozy little universe. It is true that the ancients did not know as much as we do, but they were not stupid. For example, Ptolemy knew the universe is enormous. In the “Almagest,” his famous work on astronomy, he wrote that the earth, in relation to the distance of the fixed stars, has no appreciable size and must be treated as a mathematical point.
Not only did Ptolemy know that we live in an immense universe, he also knew that the celestial bodies behave in certain highly predictable ways. On a certain night of the year Orion, for example, is always in the same place in the sky. While the stars seemed to be fixed in place, the planets seemed to wander among them (“planet” means “wanderer”). Ptolemy combined these observations with his belief that the earth was the center of the universe and developed a system, a theory, that predicted the movements of the celestial bodies with great accuracy.
Briefly, in Ptolemaic cosmology “deferents” are large circles centered on the Earth. “Epicycles” are small circles the centers of which move around the circumference of a deferent. So the sun, the moon and the planets have their own epicycles, and each epicycle in turn moves along a deferent around the earth. This system sounds very complex, and it was. But it provided astonishingly accurate predictions of the movements of the celestial bodies. In Ptolemy’s “Handy Tables,” one could find all the data needed to predict the positions of the sun, moon, planets and stars and also eclipses of the sun and moon.
Ptolemy’s system was so good that it was the basis upon which celestial predictions were made for over a thousand years. Copernicus first published his theories in 1543. Forty years earlier, armed only with his knowledge of Ptolemy, Columbus was able to awe the Indians on present day Jamaica by predicting the lunar eclipse of February 29, 1504.
Importantly, note that Ptolemy’s system has every attribute of a sound scientific theory, and if the scientific method had been around in his day, scientific experiments would have supported his theory. For example, suppose Ptolemy was interested in accounting for the observed movement of Mars across the sky. He could have used the steps of the scientific method as follows:
1. Question: What accounts for the observations of Mars’ movements across the sky.
2. Hypothesis: Mars orbits a certain epicycle which in turn moves around the circumference of a certain deferent.
3. Observation/test: When we look at the sky and make numerous detailed observations of Mars’ position, we see that Mars’ motion though the sky is perfectly consistent with the posited epicycle and deferent.
4. Conclusion: The hypothesis is not falsified.
5. Theory: This non-falsified hypothesis is consistent with the general theory that all celestial bodies move along epicycles and deferents.
Ptolemy’s cosmology was accepted for over 1,400 years. It began to crumble only when later observations of the celestial bodies required more and more and more adjustments to the theory so that it became staggeringly complex. Along comes Copernicus with a judgment based upon his religious sensibilities: Surely God would not have designed such a clunky universe. There has to be a more elegant answer. And motivated by his essentially aesthetic judgment, he developed a heliocentric cosmology that gradually displaced Ptolemy.
Yet another modern conceit is that scholars in Copernicus’ and Galileo’s day rejected heliocentric cosmology for dogmatic religious reasons even though the conclusion that Copernicus’ model was superior was intuitively obvious to even the most casual observer. This is simply not true. Yes, religious considerations motivated opposition to Copernicus to a degree. That cannot be denied. Nevertheless, the conceit is false. Sixteenth century scholars were not motivated SOLELY by religious considerations as the conceited modern would have it. They had good SCIENTIFIC arguments to support their position. These arguments turned out to be wrong, to be sure, but it is important to remember that they were not utterly unreasonable.
Ptolemy was wrong, but he was not stupid. His beliefs were justified in the sense that there was substantial evidence to support them. He observed the celestial bodies move in certain ways; from his perspective the sun appeared to orbit the earth. Even today we say the sun rises when we know it does no such thing. Ptolemy’s fundamental assumption was that the earth is the center of the universe. His assumption was not based upon dogmatic anthro-centrism. He argued for his conclusion based on the data he observed. Ptolemy believed that all bodies fall toward the center of the universe. All falling objects are seen to drop toward the center of the earth. Therefore, the earth must be the center of the universe. Ptolemy rejected the notion that earth rotates on the ground that objects thrown into the air fall back to the same place from which they were thrown, which would be impossible if the earth were rotating beneath them while they were in the air.
But the most fundamental reason that scholars did not immediately roll over and accept Copernicus was the fact that, for all its clunkiness, Ptolemy’s system had for 1,400 years provided exceedingly accurate predictions about the movements of the celestial bodies. They said, “The system we have accounts for the observed data exceedingly well and has done so for well over a millennium. The burden is on you, Copernicus and Galileo, to show us why we should abandon it.” Only in retrospect, with the advantage of 500 years of experience, do we look back on the scholars of Copernicus’ day with contempt.
For our purposes it is important to note that for the most part, the “facts” Copernicus used to develop his theory were the same “facts” Ptolemy used to develop his. Copernicus looked at the sky and saw the same movements of the celestial bodies Ptolemy saw. But by the time of Copernicus there had been many additional observations, and Ptolemy had had to be tweaked again and again to account for these new observations, and Copernicus began to suspect that these tweakings were ad hoc, and perhaps the theory itself needed to be reexamined. The death blow, of course, was Galileo’s observations – made possible by improvements in telescope technology – of the four largest moons of Jupiter. If moons orbit around Jupiter, it is obvious that not everything orbits the earth as Ptolemy believed.
Now what does all of this have to do with the statement under consideration: “We can be as certain that the diversity and complexity of living things arose by chance and necessity through BWD as we are that the earth orbits the sun.”
Once we understand basic principles of epistemology, we understand that this statement is obviously false. Breaking the statement down we see that it combines three propositions: (1) We know the diversity and complexity of living things arose by chance and necessity through BWD. (2) We know the earth orbits the sun. (3) Our knowledge of “facts” (1) and (2) is epistemically equal.
But it takes no great perspicuity to see that statement (1) is at a wholly different epistemic level than statement (2). Statement (2) is an objective and verifiable observation. We have gone into space and actually observed the earth orbiting the sun. Conversely, statement (1) has not been the subject of a direct, objective and verifiable observation. No one has ever observed any living thing evolve into a different species. Inescapable conclusion: Statement (3) is false.
Now all of this is not to say that I am certain that the diversity and complexity of living things did not arise by chance and necessity through BWD. I am in fact not certain at all. While I personally do not believe it, this proposition may be true. My point is not to “disprove” Darwinism. My point is that the debate will be much more robust if we all use proper epistemic categories. The story of Ptolemy is a cautionary tale for those who would make statements like the one we discussed above. There are obvious parallels between Ptolemy and Darwin.
1. Ptolemy was a brilliant astronomer who made countless highly detailed observations from which he developed a theory of cosmology. Darwin was a brilliant biologist (despite the fact that he had no formal credentials in the discipline) who made countless highly detailed observations from which he developed a theory of evolution.
2. Ptolemy’s theory is based on a fundamental assumption: the earth is the center of the universe around which all celestial bodies orbit. Darwin’s theory is based upon a fundamental assumption: chance and necessity are the only forces available to account for the diversity and complexity of life.
3. If Ptolemy’s fundamental assumption were correct, something like his cosmology is NECESSARILY true as a matter of logic. If Darwin’s fundamental assumption were correct, something like his theory is NECESSARILY true as a matter of logic.
4. Given the information available to him, Ptolemy’s theory accounted for the data brilliantly. Given the data available to Darwin (and indeed to all biologists through about 1950), his theory accounts for the data brilliantly.
5. New data was observed, and numerous ad hoc adjustments had to be made to Ptolemy’s theory. New data arose (for example, it is now generally accepted that the fossil does not support gradualism in the way Darwin envisioned), and ad hoc adjustments to the theory have been made (e.g., punctuated equilibrium).
6. A new theory (heliocentrism) was proposed to compete with Ptolemy. The new theory rejected Ptolemy’s central assumption, but Ptolemy’s defenders clung to the old theory in large part due to their metaphysical/philosophical/religious commitments and refused to give the new theory a fair evaluation. A new theory has arisen (ID) to compete with Darwin. The new theory rejects Darwins’s central assumption by positing that a third force (agency) may account for the data. Darwin’s defenders cling to the old theory in large part due to their metaphysical/philosophical/religious commitments and refuse to give the new theory a fair evaluation
7. Ptolemy and Copernicus were attempting to develop a model that accounted for the same “facts,” i.e., the observed motions of the celestial bodies were the same for both camps. Darwinists and ID theorists also must deal with the same “facts.” For example, the fossil record is a fact. Both camps have to deal with the same fossil record. It is the interpretation of the facts, not the facts themselves that make the difference.
8. In the end, new technology made it possible for profound new data to be discovered that simply could not be accounted for in Ptolemy’s theory (Jupiter’s moons orbiting around that planet). In recent years new data has been discovered (staggeringly and irreducibly complex nano-machines in the cell; extraordinarily complex specified information stored in the DNA molecule) that cannot be accounted for in Darwin’s model. Consider: Is the electronic microscope analogous to Galileo’s improved telescope?
9. Pope Urban VIII persecuted Galileo for his “heretical” ideas in opposition to Ptolemy. High priests of an entrenched and hidebound secular orthodoxy persecute ID proponents for their “heretical” ideas in opposition to Darwinism and the philosophical materialism upon which it is based. Consider: Is Richard Dawkins analogous to Pope Urban VIII? Are Dembski and Behe the new Copernicus and Galileo?
This has been fun to write. I hope my readers enjoy it and find it useful.