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In our site guestbook, we received the following posting from Mr. Tildon Chavers Jr., a high school chemistry teacher in Pace, FL:

Good site. However, since you did not list "the theory of evolution" as one of the irrational and unscientific myths that you attempt to debunk, am I to assume that you are not as skeptical as you pretend? Anything that demands we put our faith in a list of unprovable assumptions and events that cannot be verified by independent and unbiased witnesses should be suspect. Don't you agree?

A statement like this one, of course, demands a response. Here is the response to this entry from one of our members:

Dear Mr. Chavers,

Thank you for your response to our website. Actually, we do address the evolution issue on our site, under the "current events commentary" link. The reason we do not list "the theory of evolution" as one of the irrational and unscientific myths that we debunk is that it simply does not fit in that category. To claim that it does betrays a very common confusion concerning the nature of both science and the evolution issue.

Evolution is more than just a tentative hypothesis for origins (which in any case is not the operational definition of "theory"). It is an observed fact, seen very clearly in both the fossil record (where contrary to creationist claims, many species' lineages can be traced at very high resolution) and in nature today. There are competing "theories of evolution" (differing only in the details) which attempt to explain how this observed phenomenon occurs, and the choice between them will depend on the degree to which they correspond with what is observed. An analogy can be made with gravity. It is an observed fact that objects on the Earth are pulled towards the center. This fact is not subject to dispute. It wasn't until Newton, and later Einstein, constructed theories of how gravity worked, and made testable predictions, that we had models with which to meaningfully describe this fact. The same is true of the fact of evolution. The predictions that the umbrella "theory of evolution" makes about how evolution works have been verified in the field and in the laboratory to an overwhelming extent (although the particulars, like the question of punctuated equilibrium versus gradualism, are still open to debate). The function of a skeptic is not to believe nothing- it is to accept claims about the natural world only to the extent that such claims have been rigorously verified. Evolution satisfies this criterion in spades. It simply is not reasonable to doubt that it occurred. If you would like documentation of some of the evidence for evolution, check out "Observed Instances of Speciation" and especially the "Transitional Vertebrate Fossils" faq at talkorigins.org. Again, thanks for responding!

Sincerely,
Trent Schindler
Treasurer, Penn State Skeptics Club


After I sent this message, I received another from Mr. Chavers. Thinking this would be a good learning experience, I obtained his permission to publish our dialogue on this site. Mr. Chavers statements are in pink print, while mine are in yellow. I have edited nothing from the body of his message. --Trent

Trent,

Thanks for responding to my response to your page. The assertion that evolution has been "observed" is ludicrous from a scientific standpoint, unless you know of some 500,000,000 year old evolutionists who have observed it take place over time.


Before making such a rash statement, please look over the "observed instances of speciation" faq at talkorigins.org. Evolution has, in fact, been observed numerous times. Admittedly, the cases listed in the faq do not represent "macroevolution," but we would not expect this to be the case, as macroevolution occurs on long timescales. Many creationists attempt to define away this devastating evidence with an overly restrictive definition of evolution which deliberately excludes troublesome cases such as these. In the true definition, evolution (as biologists actually use the word) is occurring, and being observed, in the present day.

But for the sake of argument, let us assume that this is not the case. The basic point of your statement can be taken to be that anything which is not directly observable cannot be studied scientifically. Science would indeed be in a sad state were this the case! But this statement is simply untrue. Most "scientific" knowledge has been obtained through indirect means, through inference. No one, for example, has ever directly observed an atom. We infer its existence through the effects that it produces on macroscopic objects. Even the images that are produced of individual atoms (for example the famous spelling of "IBM" with xenon atoms) are the result of quantum mechanical effects producing a pattern on a computer monitor, and cannot be thought of as "direct observation." Yet (I'm sure that you, as a chemistry teacher, will agree) it would be unreasonable to deny that atoms exist, or to maintain that the study of them is unscientific. (The argument could of course be made that *nothing* is directly observable. I'll stay away from this wrinkle, though it would not compromise my point.)

Evolution is in principle no different from this example. Through the physical evidence present in the fossil record, lines of evidence drawn from molecular biology, and anatomical studies of many different species, we infer that evolution has occurred. This process is far from being unscientific. In fact, it is how most science is done.


The fossil record, like any other scientific data, must be interpreted and herein lies the rub. Every scientist, including skeptics, comes to science with an a priori world view that colors everything they observe. To use the fossil record as proof of evolution begs the question (petitio principii).

Hmmm... I detect, hidden within the statement "The fossil record must be interpreted" the tacit assumption that the record is everywhere sufficiently ambiguous as to allow several wildly different interpretations. This is not the case. As can be seen in the "transitional vertebrate fossils" faq at talkorigins.org, there are many lineages which unambiguously allow only an evolutionary interpretation (barring a creator who tosses red herrings into the fossil record just to throw us scientific types off the track), including smooth species-to-species transitions where the intermediates vary only incrementally, but the species on the endpoints are completely different. Thus, this argument is not robust enough to overcome the overwhelming evidence that evolution has occurred. I must confess I don't understand why you make the claim that using the fossil record as extremely strong evidence (not proof- I'll come to that) of evolution is begging the question. Can you explain (without appealing to the inaccurate assertion of many creationists that "the rock dates the fossils, and the fossils date the rock.")?

My contention is that theories of origin are not a part of science at all and never can be unless we successfully master time travel in both directions. Philosophy and religion are more suited for such debates since hard scientific data do not form the foundation of such belief systems.

It's unclear to me why theories of origin should arbitrarily be excluded from the gaze of science, if not because some people find the conclusions of such ideas distasteful. The argument I made above applies here as well.

Philosophy's track record in terms of making statements about the physical world which can be rigorously verified is spotty at best. Religion's record is infinitely worse. I can think of no such statements that any religion has produced. It is precisely because hard scientific data do not form their foundation that philosophy and religion are unsuitable for this purpose. Whether we evolved or were created by God fully formed, our origin is embedded in physical reality. Science is the best tool with which to probe the physical world. Thus, it is highly appropriate to use science in the study of origins.


Speaking of belief systems, the scientific method is based on a logical fallacy (do you know which one?) meaning it has never really proven anything; it just increases the probably that something is true. And, science must have faith in three things it is incapable of proving before it can even begin to be science. Do you know what those three things are? These two philosophical statements always lead to some most interesting discussions!

This is a separate question altogether, and has no real bearing on the issue of whether evolution is a scientific theory, since this approach seeks to dismantle science itself. But this kind of subject inevitably pops up in discussions such as these, so here I go-

Presumably you are referring to the fact that science is inductive, thus we never know with absolute, 100% certainty that the statements it makes are correct, even if they are supported with mountains of evidence. There could always be that one exception we haven't found. Similarly, just because they are true today, this doesn't mean that science's statements are necessarily true tomorrow, or were true in the past. Thus science never "proves" anything. This is an accurate assertion, and no scientist would dispute it. It is not a problem, however. There is no real functional difference between "absolutely true" and "overwhelmingly probable." For example, I cannot prove that the sun will rise tomorrow morning. However, I CAN assert, based on the fact that the sun has risen every twenty-four hours for the whole course of human history, that the overwhelming probability is that it will rise. It would be unreasonable and absurd to doubt that it will happen. Scientists define "facts" along similar lines, as propositions which it would be unreasonable to doubt are true. Science also presupposes that the universe has a logical order. Only in the very weakest sense can this be considered "faith," as during hundreds of years of scientific inquiry no example has arisen which would show this assumption to be false. Thus is it is overwhelmingly probable that the assumption is true (a fact, in the scientific sense of the word). And it is faith in a vastly weaker sense than that of the faith required for one to assert that evolution never happened, in the face all the accumulated evidence to the contrary from many different lines of inquiry.


The next installment followed followed fairly quickly. Only greetings and premiliminaries have been edited from the messages:

I take no issue with the idea of speciation. What I take issue with is the considerable leap from speciation to the pronouncement that all life evolved from a single cell (or whatever the current contention is). This is analogous to the grand leap in going from the unmoved mover of Aristotle to the imminent and transcendent God of the New Testament. In neither case does the former imply the latter.

It is not a large leap at all. In fact, it is implied by speciation alone, although speciation is not the only evidence we have. Given the occurrence of speciation, there is only one direction that life on Earth can take (without making an unwarranted assumption of fixed numbers of species), and that is toward increasing diversity. This is simply a consequence of the fact that as a new species appears, the original species does not necessarily disappear. This implies that far in the past, there was less diversity, and even farther back, a common ancestor. The idea of speciation is the heart of evolution. The statement "I accept speciation, but not evolution" is simply incoherent. And remember, as I said above, speciation is not the only evidence. Combining the observation of present-day speciation with the fossil record and phylogenetic arguments makes the case iron-clad. (And if you're not sure what the current contention is, how can you argue against it?)

Remember what I said earlier about a priori assumptions. We all tend to find the proof that we are looking for, which is why peer review is such an important part of the scientific process.

It's ironic that you bring up the subject of peer review. You do of course realize that it is precisely this process which has partly contributed to our current understanding of how evolution works? If the statement "we all tend to find the proof that we are looking for" were true in the overly simplistic way in which you seem to mean it, science would not work at all (and as a science teacher, I should think you would find this unacceptable). The statement is true, however, only in two very limited senses:

1. It is true that individual scientists interpret data based on preconceived ideas, which possibly may lead to misinterpretation. However, these types of errors tend to be corrected relatively quickly, as other scientists zealously attempt to find chinks in the work, or later inquiry reveals that the interpretation is incorrect. The former process should not be underestimated. Scientists take great pleasure in trying to bring down sacred cows. Therefore, at the end of the day we can be quite confident in the veracity of the ideas that have survived the gauntlet.

2. Prevailing ideas in science do serve as a guide in deciding what questions to ask of nature. Despite the specious arguments of many epistomological relativists, this is not a problem. It simply means that out of the entire set of possible questions we can ask, we are concentrating on a few subsets at any given time in history. This invalidates neither the questions asked nor the answers received, but does mean that our knowledge, correct as it may be, is nevertheless incomplete. Incomplete knowledge does not damn science, either. The fact that we can't know everything doesn't mean we can't know anything. And haven't we already determined that science does not claim to, and cannot, prove anything? By using that word here, and in later passages as well, you appear to setting up an obvious straw man.


Anything that is not directly observable cannot be studied scientifically. This is not an opinion but forms the basis of the scientific method. You may need to review what science is and how it is done.

I'm sorry, but you are mistaken, on two counts. The first is that anything that is not directly observable cannot be studied scientifically. I have already addressed this issue. I would like to suggest, however, that this is yet another example of the creationist tendency to restrict definitions to exclude troublesome ideas. The second is the implicit assumption that such a thing as "the scientific method" exists. In fact, there is no single, linear, universally applied method of doing science (See "Science and its Fabrication," by Alan Chalmers, University of Minnesota Press, 1990, as well as "The Nature of Scientific Thinking As Reflected by the Works of Biologists & by Biology Textbooks," by Al Gibbs and Anton Lawson, in American Biology Teacher 543 (1992) for discussion) . This is a myth that has unfortunately been perpetuated in high school and introductory college textbooks since the 1940's, and persists because of its heuristic usefulness. It is merely an idealization, however, and has very little to do with the way scientists actually do science. The last sentence in this passage is also quite ironic!

You stated that most scientific knowledge has been obtained through inference. I don't think you mean inference as the result of guessing but rather as a conclusion made from facts or premises.

When is inference EVER the result of guessing? Why would you say this, if not to insinuate that I am somehow unsure of the definition?

I will agree that the process begins with inference but if it stays there you don't have a scientific fact or law but a theory at best and maybe not even that.

This passage seems to indicate a profound misunderstanding of the concepts of "fact," "law," and "theory." You also load the phrase "theory at best and maybe not even that" to make it seem as though a theory is something less than it really is. I'll come to that in a moment. But first I must deal with this digression:

There is a great deal of evidence to some people that humans have been abducted by alien life forms and taken off into space. What should we do with these claims? Infer they are nuts? Infer from the uncanny similarities of stories that they are speaking the truth? Or maybe study the problem scientifically by conducting research that can be duplicated and verified? If all we need is inference to have true science, the Huns are indeed amounts us!

This passage has nothing to do with inference, and everything to do with acceptable standards of evidence. There is no credible physical evidence that humans have been abducted by alien life forms. The similarity of these stories is generally quite overstated; in fact, the conception of a typical "space alien" has changed considerably over the past fifty years, probably due to cultural factors. The appropriate science with which to study these claims is psychology, which *has* actually addressed this issue. Psychologists have determined the most likely cause of abduction experiences to be a combination of agents such as sleep paralysis, temporal lobe epilepsy, fantasy proneness, and cultural influence. "Abduction experiences" have actually been induced in the laboratory by the stimulation of certain areas of the brain with weak magnetic fields, simulating a temporal lobe seizure. There is nothing about the abduction phenomenon from which we can infer that humans are *actually* being abducted. Thus, your argument, which I presume was meant to be a kind of reductio ad absurdum approach, fails.

We still speak of the theory of evolution, not the law of evolution. But we speak of the law of gravity, not the theory of gravity because a multitude of observable experiments by many people over many years developed the theory into an accepted law.

This passage amply demonstrates the profound misunderstanding I mentioned above, and is completely wrong. Theories do not become laws. Theories and laws are two separate, distinct categories; there is no crossover (See "The Laws are Mature Theories Myth," by Jack Horner and Peter Rubba, in The Science Teacher, 46(2), 1979, for discussion). Laws are purely descriptive statements about nature, and do not explain the phenomena that they describe; theories are overarching explanatory conceptual frameworks, often utilizing laws in the explanation. Rigorous verification may promote a theory to accepted fact, but it is still termed a theory. This is not to ascribe any kind of provisional status to the framework; it is just to indicate that the framework falls into the "explanatory" category, rather than the descriptive. Similarly, laws are also facts, but they are still called laws.

You state that the "theory of gravity" was developed into a law. Unfortunately, this is not only incorrect historically (Newton is famous for having said "I frame no hypothesis" in reference to gravity, i.e. he could only describe, but not explain, the phenomenon) but a flat out impossibility. In fact, a theory of gravity postdated the laws of gravity by hundreds of years. It wasn't until Einstein developed general relativity, a theory from which the laws of gravity could be derived, that an explanation was possible. To sum up, from a theory we might derive laws, and a theory might utilize laws, but a theory can never become a law. This is why we do not speak of a "law of evolution." The theory of evolution is a conceptual framework which explains why we see transitional forms, speciation, etc., and has been rigorously verified (though as I have said, the details are still subject to contention) to the point where it is considered fact. Evolution will not become a law, and no one claims that it will, not because it is on some lower tier of the mythological theory -> law hierarchy but because the category does not apply.


More recently the theory of relativity became the law of relativity because of the many observable experiments that have been done over the past fifty years accumulated enough evidence of the theory's truth to make it an accepted law.

A "law" of relativity? I'm sorry, but you're mistaken; there is no such thing, and can never be, for the reasons listed above. (Can you provide a reference for this fact?) Perhaps you're confusing Einstein's theory with the Newtonian principle of relativity, which Einstein generalized to state that physical laws are constant in unaccelerated reference frames. This has been called a law, and Einstein used it to formulate the special theory, but general and special relativity are in no way laws, despite (like evolution) being overwhelmingly verified.

Simply changing the definition of the word "theory" won't make evolution a law ('theory' is derived from the Greek word theorein which is 'the act of viewing').

Agreed. Evolution will never become a law. But this is not a liability.

You mentioned that no one has ever directly observed the atom. True enough. That is why we talk of the quantum theory of the atom. We don't know if it is true or not, only that it seems to answer some questions pretty well at the moment. No, I would not deny that atoms exist just because I have never seen one.

My argument was that we haven't directly observed atoms, yet we know they exist, and it would not be unscientific to study them; hence indirect observation does not rule out scientific inquiry, as you would claim. If you will not deny that atoms exist, or state that it is unscientific to study them, you cannot use the "no direct observation" argument as a criterion to reject evolution. (And I once again stress, and you yourself have admitted, that speciation *has* been directly observed.) Thus, you have defeated your own argument. You also seem to be confusing the fact that atoms exist, which was demonstrated by experiment decades before quantum theory came about, with the theory that explains how an atom behaves. Your statement would imply that we don't actually know whether atoms exist, a curious position for a chemistry teacher to take. The theory that explains how atoms work has nothing to do with the truthfulness of the statement "atoms exist." (As an aside, you don't seem to give quantum mechanics the credit that it is due. Q.M. is the single most successful physical theory in human history, and shows every indication that it may go beyond being approximately true, as is the case with most theories. It in fact may be EXACTLY true, though incomplete. [See Steven Weinberg's "Dreams of a Final Theory" for details]. For this reason, Q.M. goes far beyond "answering some questions pretty well at the moment.")

The philosopher Democritis in about 400 B.C. suggestion the existence of atoms and even came up with the term. He did so by simple logic. Scientists have used the idea to conduct experiements and discovered the atomic nucleus, the charge of the electron, mass of the electron, etc. etc. They did these things not from simply sitting around thinking about it and inferring the results. They conducted observable experiments. That's when the atom moved from a philosophical idea to a scientific concept. Without observable experimentation that can be duplicated by other scientists you don't have science but philosophy or metaphysics.

Actually, they DID sit around thinking about it, inferring conclusions based on observations of the outcome of the experiments. Here we come to a myth about science which creationists have unfortunately exploited, making their arguments sound very persuasive to the layman. This myth would have us believe that experimentation is the central part of science. The truth is that observation takes the privileged position; experimentation is secondary. This is a sublety that is lost on many. Observation can be made of an experimental, artificially constructed situation where we set the parameters and see how this affects the outcome, or it can be made of a naturally occuring setting where we have no control over the parameters, and can merely make note of the phenomena under study. Either way, it doesn't matter; the choice of which way to study some part of nature depends on the nature of the part, but ultimately, the result is the same. This is why two of the branches of science are called "experimental science" and "observational science" (of course, overlap does occur- evolution can be demonstrated experimentally, as shown by some of the examples of speciation with which even you do not take issue). Your, and most creationists', restricted definition of science as a purely experimental enterprise would rule out observational science entirely. In your irrational zeal to discredit evolution (which assuredly IS a mostly observational science), such subjects as observational astronomy would be deemed unscientific, which is clearly not so. Another point deserves to be mentioned here, and deals with the nature of the observation of predictions. Foes of evolution would like us to believe that the term prediction applies in only one direction, towards the future; thus evolution cannot be studied scientifically because (they say) it only occurred in the past. This is untrue. Theories make predictions about past events in this way- A theory may predict that if A occurred at some point in the past, we will find B evidence of A's having occurred if we look. Thus a prediction becomes a "postdiction." This is a routine part a science, and invalidates a major creationist argument.

You seem to have a problem understanding my arguments from philosophy.

I don't believe I have any such problem. Here's a synopsis for those who came to the theater late:

You have ventured two separate arguments, which are not entirely consistent with each other.

1.
  • Premise : If science is based on faith, then it can not claim preferred status over other systems of belief.
  • Premise : Science is based on faith.
  • Conclusion: Science can not claim preferred status over other systems of belief.

2.
  • Premise : If a physical phenomenon can not be observed directly, it can not be studied scientifically.
  • Premise : Evolution can not be observed directly.
  • Conclusion: Evolution can not be studied scientifically.

A variant of 2 is this:

  • Premise: If a physical phenomenon has taken place only in the past, it can not be studied scientifically.
  • Premise: Evolution took place only in the past.
  • Conclusion: Evolution can not be studied scientifically.

Does this sound close? Notice that if the first argument is true, it renders the second powerless. This is what I mean by "not entirely consistent." I have demonstrated that both of these arguments fail. The first fails because it depends on imprecision. I have shown that the "faith" demonstrated by scientists is of a substantially different nature than that required in, say, religion. Since the validity of the argument depends upon ambiguity in the definition of the term "faith," you have commited a fallacy of equivocation. Argument 2 fails because neither premise is true (in either variant), as I have previously demonstrated, thus your conclusion is invalid. You are therefore begging the question. So the problem is not that I misunderstood your arguments from philosophy, it's that I don't think that they were particularly good arguments to begin with.


Since you are a graduate student (presumably in science) I certainly hope that you have been given at least some basic instruction in the philosophy of science. Without an understanding of the nature and limitations of our chosen field we tend to wander off into scientism, then nobody invites us to parties anymore. : o )

I feel pretty secure with regard to the adequacy of my education. Thanks for the concern, though! :-)

Perhaps we need to define what we mean by evolution as well as come to an agreement as to how science is done.

Depending on context, I use two definitions of evolution. The first describes the observations that we make, the second describes the theory that explains these observations. It is perhaps unfortunate that both are called "evolution," as this provides some confusion, but that's the way the cookie crumbled. These definitions are my own. Other scientists might disagree with the fine points.

Evolution (observation)- The word evolution applies to the set of observations which include, but are not limited to: a. the existence of finely graded, incrementally differing species extant in the fossil record, which vary greatly at the endpoints of any given trace along lines of similarity (the quality of this observation is dependent on the age of the record, and is best for the relatively young parts) b. The observation of decreasing diversity with age in the fossil record (e.g. if we look far enough back in time, we see only invertebrates; even farther back, and we only see evidence of bacterial processes.) c. The observation of the similarities and differences in the genomes of various species. d. The observation of species-to-species transitions occurring today, as well as such phenomena as the occurrence of drug-resistance in microbes. -I'm sure I've left stuff out of this list, but this is enough for now.

Evolution (theory)- The theoretical framework which explains the above observations in terms of the occurrence of heritable changes in the genome, combined with selection pressures produced by environmental factors (other processes, such as geographical isolation, probably contribute as well). The appearance of increasing diversity and complexity with time is an epiphenomenon which, while indirectly associated with evolution, is not central to it.

For the discussion of how science is done, see the various parts of this message.


I do contend, however, that without experimentation you will be unable to move from theory to law. Otherwise there is no real difference in science and philosophy and there is no way to verify a person's conclusions.

This assertion, and the "theory to law" myth, have already been addressed above.

You said: "[Inference] is far from being unscientific. In fact, it is how most science is done." I say: Most science is not done by inference.

Okay, since you didn't like my example of the atom, here are two more examples. No one has ever directly measured the curvature of spacetime. We infer the existence of spacetime by measurements done of such disparate phenomena as the weight of an object in a gravitational field, apparent anomalies in the orbit of mercury, gravitational lensing events, and binary star systems which are energetically "winding down" in a manner consistent with the radiation of gravitational waves. I know of no one who would make the claim that it is "unscientific" to study spacetime in this manner. We have a similar example from quantum mechanics. No one has "seen" a quantum mechanical wavefunction. Yet it is absurd to deny that it is scientific to study a Q.M. wave, since we clearly and unambiguously see the effects which would be produced if it existed; thus we infer that it exists (in whatever form it might take). The only difference between these examples and evolution is that in addition to indirect study, we can also study it directly, since we observe it going on today.

Most theories are arrived at by inference but the process does not stop there. Unless something is done that can be verified by other scientists all you have in the end is someone's opinion. Science is not opinion but verifiable fact obtained from many years of careful experimentation, observation, and verification over and over again. If all you have is circumstantial evidence, you had better have a lot of it that can not be reasonably interpreted any other way.

Isn't it wonderful, then, that evolution satisfies all these criteria? Seriously, though, inference is the heart of experimentation, observation, and verification. You just can't get away from it.

I said: The fossil record, like any other scientific data, must be interpreted and herein lies the rub. Every scientist, including skeptics, comes to science with an a priori world view that colors everything they observe. To use the fossil record as proof of evolution begs the question (petitio principii). You said: "Hmmm... I detect, hidden within the statement "The fossil record must be interpreted" the tacit assumption that the record is everywhere sufficiently ambiguous as to allow several wildly different interpretations." I say: Wrong. All scientific data must be interpreted by other scientists as well as the one doing the science. Every scientist knows this, which is why "peer review" is so much a part of the scientific process.

You are simply repeating an argument you've already made. I've addressed both the issue of peer review, and the issue of interpretation, above.

You said: [T]here are many lineages which unambiguously allow only an evolutionary interpretation ... including smooth species-to-species transitions where the intermediates vary only incrementally..." I say: Smooth species-to-species transitions? In over thirty years of studying biology and other sciences I have never found anything purported to be proof that one species ever evolved into another. Please tell me more about this breakthrough!

Well, since you asked... I have sent a list of just a few examples in another message, complete with references, which I have adapted from the talkorigins FAQ. (The interested reader can find these examples at the "Transitional Vertebrate Fossils" FAQ.) Be forewarned, the list is quite long. It is incomplete, however, dealing only with mammals, and restricting itself to the relatively recent period of the Cenozoic, where we have the best preservation record. This is to be expected; the younger the samples, the better the preservation. There are many more smooth species-to-species (even genera-to-genera) transitions than these examples indicate, but it's best not to belabor the point. Most of the references should be available in a local university library, should you wish to look them up. (And hey, there's that "proof" word again. Who said anything about proof? These examples offer overwhelmingly strong evidence, which luckily is functionally identical to proof. We better not do any smoking around here- all the straw men will go up in flames!)

You said: "I must confess I don't understand why you make the claim that using the fossil record as extremely strong evidence (not proof- I'll come to that) of evolution is begging the question." I say: Try this reasoning: "If evolutioin is true then there would have to be a fossil record. There is a fossil record, therefore evolution is true." Nope, thats not begging the question, its affirmation of the consequent, also a logical fallacy.

Hey, you're the one who said it was begging the question, remember? And my goodess, what have we here? Yet ANOTHER straw man! Remember, he who lives by the sword, dies by the sword. If you're going to place such an emphasis on logic I would urge you to make sure your own arguments are sound. Even if this syllogism were valid, the premise is not even remotely correct, and no scientist that I know of would say such a thing. The existence of evolution does NOT imply that there will be a fossil record. The existence of the fossil record is dependent on the processes of preservation, which are reflections of the environment. It is easy to imagine a world on which evolution is occurring, but the environment is such that preservation does not occur, leaving no fossil record. Of course, this is irrelevent to the validity of the syllogism, which you seem to have deliberately framed to be indefensible. Actually, syllogistic arguments are inapplicable to either scientific theory or observation, for reasons I'll make clear in a moment. But first:

Let me turn it around: "Iif there is a fossil record, then evolution must be true. There is a fossil record, therefore evolution is true." Good form but bad science. Why should the fact of evolution be inferred from the fossil record alone? I don't think any palenontologist would do so. You can't have it both ways, only one way. To try to state the problem both ways is arguing in a circle.

Straw man #4. Do we want to shoot for five? I hope not. As I have indicated above, evolution and the existence of the fossil record are not causally related in this sense. It is easy to imagine a world populated by life which was created fully formed by a powerful being, yet has the same processes of fossilization and preservation that we have on Earth. Thus, once again, your premise is incorrect, and I know of no scientist that would say such a thing. Evolution predicts that given a sufficiently detailed fossil record, we will find transitional fossils. We find transitional fossils, so we consider it reasonable to take this verified prediction as strong evidence, not logical proof, of evolution's having occurred. And as I have made clear several times, evolution is not inferred from the fossil record alone, but from many different, complementary lines of evidence. It is curious that you would pose this problem syllogistically. Syllogisms, if they are not fallacious, are logical proofs. If syllogistic arguments were applicable to scientific theory or observation, then proof would be within the means of science. Yet as I have stated ad nauseum, science cannot provide proof of anything, just overwhelming evidence. You apparently agree with this statement. I am therefore baffled by your insistence on my providing proof of evolution, if it is not an attempt to rig the debate.

I suggest that all science students be required to take a few courses in the philosophy of science before being allowed a science degree. Perhaps then some of the positions could be stated better and some arguments wouldn't be made at all.

I agree. But if you are implying what I suspect you to be, I would ask you to look over the last few pages again.

You said: "It's unclear to me why theories of origin should arbitrarily be excluded from the gaze of science, if not because some people find the conclusions of such ideas distasteful." I say: Science is unable to prove anything relative to the creation of the universe. This is not arbitrary. Circumstancial evidence has executed innocent people and turned the guilty free. Science deals with proof, not speculation or accumulated opinion.

Proof?! *Sigh*. If you'll look at your first dispatch, you'll see that you yourself wrote that science cannot provide proof. Do I need to point out the contradiction here? Isn't it about time that you drop this particular line of argument? And Whoa, when did we start talking about the creation of the universe?! I thought we were just talking about biological evolution! There is plenty of spectactularly good evidence addressing the origin of the universe, including the cosmic background radiation, the cosmological redshift, H/He/Li/Be abundances, etc. But that's another conversation entirely, and I won't go into it here.

Let's take an example. The celebrated physicist Steven Hawkin proposed that when the Big Bang runs out of bang and the universe begins to collapse back onto itself, time would then run backwards. We will walk backward, talk backward, go from old to young then reenter the womb, etc. He had his reasons for proposing this, something about space-time I think. He wasn't joking, he was serious. His colleges finally convinced him that the math didn't bear out that hypothesis so he abandoned it. Will we ever know for sure? No. We won't live long enough to experience it and if we did we may not even know we were going backwards (I'll let the serious philosophers handle that one). You can speculate all you want but the fact is you will never know for sure.

Even if Hawking's hypothesis HAD been borne out, the only lesson to be taken from this example is that our knowledge of the state of the universe will always be incomplete. Why is this a surprise? No scientist that I know of would disagree with this statement. As I have said before, the fact that we can't know everything does not imply that we can't know anything. But since the hypothesis was flawed to begin with, your example is doubly irrelevent.

Not even observation is certain. "No obervation can prove a theory true, but can at best permit it to survive until it is tested again" (Karl Popper, philosopher of science)

Observations are subject to uncertainty. However, as many observations are made, statistical forces come into play, and we obtain a strong signal from the noise. Over the course of decades, the sum of these observations approaches certainty. So your objection has no power. (It should also be remembered that while Karl Popper contributed greatly to the philosophy of science, his words are not gospel. In fact a number of his ideas are demonstrably flawed, which is why in philosophy appeals to authority are frowned upon.)

Timothy Ferris in The Mind's Eye stated, "science rests on a tripod whose legs are hypothesis, observation, and faith."

While I very much enjoy Timothy Ferris's writings, and have great respect for him, he is neither a scientist nor a philosopher, but a journalist. His philosophical musings sometimes leave something to be desired. The chapter in "The Mind's Sky" from which you got this quote (and the chapter is more or less devoted to justifying it) is, unfortunately, an imprecise conceptual mess, containing a number of errors. I would therefore take what he says about the nature of science with a grain of salt (although his comments about the content of science are as reliable as one could reasonably expect in a science popularization).

If you had studied the philosophy of science you would know that science must have faith in three things it cannot begin to prove.

This is an astonishingly presumptuous statement. I find the implied condescension offensive.

In that regard it is no different than any religion in the world.

There is a vast qualitative difference. I have already addressed the faith issue, but there are other ways in which it is different, as well. Science, unlike religion, is cumulative and self-correcting. Also unlike religion, the validity of science's statements can be measured by comparison with the physical world. Science is an open enterprise, and accomodates new information about the physical world, thus allowing us to build higher and higher resolution pictures of nature; fundamentalist religion pretends it already has all the answers, and closes its eyes, ears, and mind to new evidence which suggests that it is probably wrong. These are by no means the only differences, but they are all I have time for at the moment.

If science wants to study origins, then why not study the existence of faries, flying saucers, unicorns, and debate how many angels might be able to dance on the head of a pin? Science itself knows that some things are best left to other fields of study.

The reason we don't study the existence of fairies is that there has never been any evidence to suggest that fairies actually exist. If someone were to produce evidence of the existence of fairies, the subject could legimately be studied scientifically. Indeed, scientists would be beating down the door to make a name for themselves in the field. The same goes for flying saucers and unicorns. If there was any credible evidence to suggest that angels actually exist, the debate about how many of them could dance on the head of a pin might be meaningful. But there is no evidence for their existence, so for now the debate has no meaning. In contrast, there is overwhelming physical evidence that evolution has occurred and is occurring. Thus it is subject to scientific study. There is also evidence that the universe was created in a "big bang" event tens of billions of years ago. This, too, is subject to scientific study. Any phenomenon which exists or has existed in the physical world can be subject to scientific inquiry. Religion, and to a lesser extent philosophy, while having much to say about the more "human" spheres, can produce no meaningful or intelligible statements about the physical world (I make exceptions for some subsets of philosophy, such as philosophy of mind, etc., where the distinction between philosophy and science has become somewhat blurred). Thus it is inappropriate to study questions of origins from within these fields.

You said: "Scientists define "facts" along similar lines, as propositions which it would be unreasonable to doubt are true. Science also presupposes that the universe has a logical order. Only in the very weakest sense can this be considered "faith," as during hundreds of years of scientific inquiry no example has arisen which would show this assumption to be false." I say: Faith cannot be proven, Trent. That is why it is called faith. Many religious people the world over would gladly give you "proof" that their faith is real and has real results. Would you accept their proof?

I'm not sure what this passage means. Naturally, I would not deny that many people have religious faith. Nor would I deny that the faith they possess may make them feel very good, or produce a sense of spiritual well-being. But this faith, as good as it feels, provides no evidence that the object of faith has any external existence; indeed, the idea of religious faith would be meaningless if it did. This is why the adherents of different, mutually exclusive religions can all believe fervently that THEY are the ones who are correct- religious faith does not allow itself to be constrained by the limitation of having to provide evidence for whatever claims it makes. In any case, I don't see how your statement relates to my passage. It seems to contradict itself, and it in no way addresses the question at hand. (And once again, who said anything about "proof?") Religious faith may be good for many things, but addressing scientific questions is not one of them.

I read an article in Scientific American that had been published over a century ago proving that the fastest man could ever go was 35 mph because at speeds above that he would be unable to get any air to breathe. I have seen mathmatical calculations proving that a bumble bee can' fly. The history of science, something else students should be required to study, is full of examples of cherished scientific positions falling under the weight of new information never before imagined. The theory of evolution has changed dramatically over the course of my life and will change even more during your lifetime.

Indeed, and you've just illustrated beautifully that science is self-correcting, which is its strength, not its flaw. You would have the argument framed this way:

  • Premise: If some scientists have made mistakes, then science is not the best epistomological system for exploring the physical world.
  • Premise: Some scientists have made mistakes.
  • Conclusion: Science is not the best epistomological system for exploring the physical world.


Your first premise is incorrect, and your argument fails. The use of scientific principles does not inoculate one against error. Scientists are, after all, human. Ask yourself why we no longer believe the statements you mention to be true. The answer you'll arrive at is that the evidence did not bear out the statements, or that closer inspection revealed that the calculations which resulted in the statements were overly simplistic. This is exactly why we no longer believe that the Earth was created 6000 years ago, or that all animals were created at once, fully formed, by a powerful being; this is despite the fact that early scientists believed just that. The fact that scientists can make mistakes does not diminish the scientific enterprise. It is precisely this enterprise which has revealed that these ideas are in error, and allowed correction. The "paradigm shift" idea of Thomas Kuhn notwithstanding (and it doesn't), the broad scope of modern science has been characterized by two basic trends:

1. Increasing generalization- more sweeping, general theories reveal that previous theories, while correct, are special or limiting cases of the larger ones. (e.g. quantum mechanics yields classical mechanics at large energies and masses; Newtonian mechanics is a special case of relativitistc mechanics.)

2. Increasing resolution- theories, while correct in the basic framework, are shown to have errors in the details, and these errors are eventually corrected. (e.g. Darwin's basic conceptual framework for biological evolution was correct, but he could not have anticipated the existence of DNA, so his proposed mechanism for the transfer of heritible traits was incorrect. We now know much more about how evolution works than Darwin did, but his basic idea is still valid.)

It is only on the fine scale that you see, as you have said, "examples of cherished scientific positions falling under the weight of new information never before imagined." On this fine scale the signal-to-noise ratio is relatively low (though still far superior to that present in other fields of study) but this does not appreciably affect the large scale motion of science. Your position is therefore weak. (Incidentally, the bumblebee story is probably apocryphal. I have heard it many times, but have never seen the original reference.)


Don't wrap your theories so tightly around you that you become imprisoned by them. Science will move on without you.

I don't intend to. I just wish others would take my example... ;-)