Seeing the world through Darwin’s eyes

It is good to be back and blogging again!

On my trip to Australia, I had the chance to see some of the marsupial animals that are native to that continent, and as I gazed at these strange and wondrous creatures, I asked myself the same question that all visitors to the continent before me must have asked: Why are these animals so different from the ones I am familiar with? After all, Australia’s environment is not that different from that found in other parts of the world, but the fact that most marsupials (like kangaroos, wallabies, koalas, and wombats) are found only on that continent is remarkable. I was stunned to learn that when a kangaroo is born, it weighs less than one gram. This is because much of the development of the newborn (which occurs in other animals inside the womb of the mother) takes place in the pouch for marsupials.
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Why scientific theories are more than explanations

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

At its heart, intelligent design creationism (IDC) advocates adopt as their main strategy that of finding phenomena that are not (at least in their eyes) satisfactorily explained by evolutionary theory and arguing that hence natural selection is a failed theory. They say that adding the postulate of an ‘intelligent designer’ (which is clearly a pseudonym for God) as the cause of these so-called unexplained phenomena means that they are no longer unexplained. This, they claim, makes IDC the better ‘explanation.’ Some (perhaps for tactical reasons) do not go so far and instead say that it is at least a competing explanation and thus on a par with evolution.
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Why IDC is not science

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

In the previous posting, I pointed out that if one looks back at the history of science, all the theories that are considered to be science are both (1) naturalistic and (2) predictive. Thus these two things constitute necessary conditions.

This is an important fact to realize when so-called intelligent design creationism (IDC) advocates argue that theirs is a ‘scientific’ theory. If so, the first hurdle IDC must surmount is that it meet both those necessary criteria, if it is to be even eligible to be considered to be science. It has to be emphasized that meeting those conditions is not sufficient, for something to be considered science, but the question of sufficiency does not even arise because IDC does not meet either of the two necessary conditions.

I issued this challenge to the IDC proponents when I debated them in Kansas in 2002. I pointed out that nowhere did they provide any kind of mechanism that enabled them to predict anything that anyone could go out and look for. And they still haven’t. At its essence, IDC strategy is to (1) point to a few things that they claim evolutionary theory cannot explain; (2) assert that such phenomena have too low a probability to be explained by any naturalistic theory; and (3) draw the conclusion that those phenomena must have been caused by an ‘unspecified designer’ (with a nudge, nudge, wink, wink to the faithful that this is really God) whose workings are beyond the realm of the natural world explored by science.

Thus they postulate a non-natural cause for those phenomena and cannot predict any thing that any person could go and look for. (This is not surprising. The designer is, for all intents and purposes, a synonym for God and it would be a bit bizarre to our traditional concept of God to think that his/her actions should be as predictable as that of blocks sliding down inclined planes.) When I asked one of the IDC stalwarts (Jonathan Wells) during my visit to Hillsdale College for an IDC prediction, the best he could come up with was that there would be more unexplained phenomena in the future or words to that effect.

But that is hardly what is meant by a scientific prediction. I can make that same kind of vague prediction about any theory, even a commonly accepted scientific one since no theory ever explains everything. A scientific prediction takes the more concrete form: “The theory Z encompassing this range of phenomena predicts that if conditions X are met, then we should be able to see result Y.”

IDC advocates know that their model comes nowhere close to meeting this basic condition of science. So they have adopted the strategy of: (1) challenging the naturalism condition, arguing that it is not a necessary condition for science and that it has been specifically and unfairly adopted to exclude IDC from science; and (2) tried to create a new definition of science so that IDC can be included. This takes the form of arguing that a scientific theory is one that ‘explains’ phenomena.

There are variations and expansions on these arguments by the various members of the IDC camp but I have tried to reduce it to its skeletal elements. These variations that IDC proponents adopt are designed to blur the issues but are easy to refute. See this cartoon by Tom Tomorrow (thanks to Daniel for the link) and this cartoon (thanks to Heidi) and this funny post by Canadian Cynic about the possible consequences of using IDC-type reasoning in other areas of life.)

The rejection by IDC advocates of naturalism and predictivity as necessary conditions for science goes against the history of science. Recall for example the struggle between the Platonic and Copernican models of the universe. Remember that both sides of this debate involved religious believers. But when they tried to explain the motions of the planets, both sides used naturalistic theories. To explain the retrograde motion of Mercury and other seemingly aberrant behavior, they invoked epicycles and the like. They struggled hard to find models that would enable them to predict future motion. They did not invoke God by saying things like “God must be moving the planets backwards on occasion.” Or “This seemingly anomalous motion of Mercury is due to God.” Such an explanation would not have been of any use to them because allowing God into the picture would preclude the making of predictions.

In fact, the telling piece of evidence that ended the geocentric model was that the Rudolphine Tables using Kepler’s elliptical orbits and a heliocentric model were far superior to any alternative in predicting planetary motion.

While it may be true that the underlying beliefs that drove people of that time to support the Platonic or Copernican model may have been influenced by their religious outlook, they did not seem to invoke God in a piecemeal way, as an explanation for this or that isolated phenomenon, as is currently done by IDC advocates. Instead they were more concerned with posing the question of whether the whole structure of the scientific theory was consistent with their understanding of the working of God. In other words, they were debating whether a geocentric model was compatible with their ideas of God’s role in the world. The detailed motions of specific planets, however problematic, seemed to have been too trivial for them to invoke God as an explanation, although they would probably not have excluded this option as something that God was capable of doing.

It may also well be true that some scientists of that time thought that God might be responsible for such things but such speculations were not part of the scientific debate. For example, Newton himself is supposed to have believed that the stability of the solar system (which was an unexplained problem in his day and remained unsolved for about 200 years) was due to God periodically intervening to restore the initial conditions. But these ideas were never part of the scientific consensus. And we can see why. If scientists had said that the stability was due to God, and closed down that avenue of research, then scientists would never have solved this important problem by naturalistic means and thus advanced the cause of science. This is why scientists, as a community, never accept non-natural explanations for any phenomena, even though individual scientists may entertain such ideas.

So the attempts by IDC advocates to redefine science to leave out methodological naturalism and predictivity fly completely in the face of the history of science. But worse than that, such a move would result in undermining the very methods that has made science so successful.

In the next posting, we will see why just looking for ‘good’ explanations of scientific phenomena (the definition of science advocated by the IDC people) is not, by itself, a useful exercise for science.

What is science?

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

Because of my interest in the history and philosophy of science I am sometimes called upon to answer the question “what is science?” Most people think that the answer should be fairly straightforward. This is because science is such an integral part of our lives that everyone feels that they intuitively know what it is and think that the problem of defining science is purely one of finding the right combination of words that captures their intuitive sense.

But as I said in my previous posting, strictly defining things means having demarcation criteria, which involves developing a set of necessary and sufficient conditions, and this is extremely hard to do even for seemingly simple things like (say) defining what a dog is. So I should not be surprising that it may be harder to do for an abstract idea like science.

But just as a small child is able, based on its experience with pets, to distinguish between a dog and a cat without any need for formal demarcation criteria, so can scientists intuitively sense what is science and what is not science, based on the practice of their profession, without any need for a formal definition. So scientists do not, in the normal course of their work, pay much attention to whether they have a formal definition of science or not. If forced to define science (say for the purpose of writing textbooks) they tend to make up some kind of definition that sort of fits with their experience, but such ad-hoc formulations lack the kind of formal rigor that is strictly required of a philosophically sound demarcation criterion.

The absence of an agreed-upon formal definition of science has not hindered science from progressing rapidly and efficiently. Science marches on, blithely unconcerned about its lack of self-definition. People start worrying about definitions of science mainly in the context of political battles, such as those involving so-called intelligent design creationism (or IDC), because advocates of IDC have been using this lack of a formal definition to try to define science in such a way that their pet idea be included as science, and thus taught in schools as part of the science curriculum and as an alternative to evolution.

Having a clear-cut demarcation criterion that defines science and is accepted by all would settle this question once and for all. But finding this demarcation criterion for science has proven to be remarkably difficult.

To set about trying to find such criteria, we do what we usually do in all such cases, we look at all the knowledge that is commonly accepted as science by everyone, and see if we can see similarities among these areas. For example, I think everyone would agree that the subjects that come under the headings of astronomy, geology, physics, chemistry, and biology, and which are studied by university departments in reputable universities, all come under the heading of science. So any definition of science that excluded any of these areas would be clearly inadequate, just as any definition of ‘dog’ that excluded a commonly accepted breed would be dismissed as inadequate.

This is the kind of thing we do when trying to define other things, like art (say). Any definition of art that excluded (say) paintings hanging in reputable museums would be considered an inadequate definition.

When we look back at the history of the topics studied by people in those named disciplines and which are commonly accepted as science, two characteristics stand out. The first thing that we realize is that for a theory to be considered scientific it does not have to be true. Newtonian physics is commonly accepted to be scientific, although it is not considered to be universally true anymore. The phlogiston theory of combustion is considered to be scientific though it has long since been overthrown by the oxygen theory. And so on. In fact, since all knowledge is considered to be fallible and liable to change, truth is, in some sense, irrelevant to the question of whether something is scientific or not, because absolute truth cannot be established.

(A caveat: Not all scientists will agree with me on this last point. Some scientists feel that once a theory is shown to be incorrect, it ceases to be part of science, although it remains a part of science history. Some physicists also feel that many of the current theories of (say) sub-atomic particles are unlikely to be ever overthrown and are thus true in some absolute sense. I am not convinced of this. The history of science teaches us that even theories that were considered rock-solid and lasted millennia (such as the geocentric universe) eventually were overthrown.)

But there is a clear pattern that emerges about scientific theories. All the theories that are considered to be science are (1) naturalistic and (2) predictive.

By naturalistic I mean methodological naturalism and not philosophical naturalism. The latter, I argued in an earlier posting where these terms were defined, is irrelevant to science.

By predictive, I mean that all theories that are considered part of science have the quality of having some explicit mechanism or structure that enable the users of these theories to make predictions, of saying what one should see if one did some experiment or looked in some place under certain conditions.

Note that these two conditions are just necessary conditions and by themselves are not sufficient. (See the previous posting for what those conditions mean.) As such they can only classify things into “may be science” (if something meets both conditions) or “not science” (if something does not meet either one of the conditions.) As such, these two conditions together do not make up a satisfactory demarcation criterion. For example, the theory that if a football quarterback throws a lot of interceptions his team is likely to lose, meets both naturalistic and predictive conditions, but it is not considered part of science.

But even though we do not have a rigorous demarcation criterion for science, the existence of just necessary conditions still has interesting implications, which we shall explore in later postings.

What do creationist/ID advocates want-III?

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

It is time to tackle head-on the notion of what is meant by the ‘materialism’ that the creationist/ID camp find so distasteful. (See part I and part II for the background.)

The word materialism is used synonymously with ‘naturalism’ and perhaps the clearest formulation of what it means can be found in the writings of paleontologist George Gaylord Simpson who said in Tempo and Mode in Evolution (p. 76.):

“The progress of knowledge rigidly requires that no non-physical postulate ever be admitted in connection with the study of physical phenomena. We do not know what is and what is not explicable in physical terms, and the researcher who is seeking explanations must seek physical explanations only.” (Emphasis added)

Simpson was by no means an atheist (as far as I can tell) but he is saying something that all scientists take for granted, that when you seek a scientific explanation for something, you look for something that has natural causes, and you do not countenance the miraculous or the inscrutable. This process is properly called ‘methodological naturalism’, to be contrasted with ‘philosophical naturalism.’

Despite the polysyllabic terminology, the ideas are easy to understand. For example, if you hear a strange noise in the next room, you might wonder if it is a radiator or the wind or a mouse or an intruder and you investigate each possible cause, looking for evidence. For each question that you pose, the answer is sought in natural causes. You would be unlikely to say “The noise in the next room is caused by God knocking over stuff.” In general, people don’t invoke God to explain the everyday phenomena of our lives, even though they might be quite religious.

Methodological naturalism is just that same idea. Scientists look for natural explanations to the phenomena they encounter because that is the way science works. Such an approach allows you to systematically investigate open questions and not shut off avenues of research. Any scientist who said that an experimental result was due to God intervening in the lab would be looked at askance, because that scientist would be violating one of the fundamental rules of operation. There is no question in science that is closed to further investigation of deeper natural causes.

Non-scientists sometimes do not understand how hard and frustrating much of scientific research is. People work for years and even decades banging their heads against brick walls, trying to solve some tough problem. What keeps them going? What makes them persevere? It is the practice of methodological naturalism, the belief that a discoverable explanation must exist and that it is only their ingenuity and skill that is preventing them from finding the solution. Unsolved problems are seen as challenges to the skills of the individual scientist and the scientific community, not as manifestations of God’s workings.

This is what, for example, causes medical researchers to work for years to find causes (and thus possibly cures) for rare and obscure diseases. Part of the reason is the desire to be helpful, part of it is due to personal ambition and career advancement, but an important part is also the belief that a solution exists that lies within their grasp.

It is because of this willingness to persevere in the face of enormous difficulty that science has been able to make the breakthroughs it has. If, at the early signs of difficulty in solving a problem scientists threw up their hands and said “Well, looks like God is behind this one. Let’s give up and move on to something else” then the great discoveries of science that we associate with Newton, Darwin, Einstein, Planck, Heisenberg, etc. would never have occurred.

For example, the motion of the perigee of the moon was a well-known unsolved problem for over sixty years after the introduction of Newtonian physics. It constituted a serious problem that resisted solution for a longer time than the problems in evolution pointed to by creationist/ID advocates. Yet no supernatural explanation was invoked, eventually the problem was solved, and the result was seen as a triumph for Newtonian theory.

So when creationist/ID advocates advocate the abandonment of methodological naturalism, they are not trying to ease just Darwin out of the picture. They are throwing out the operational basis of the entire scientific enterprise.

Philosophical naturalism, as contrasted with methodological naturalism, is the belief that the natural world is all there is, that there is nothing more. Some scientists undoubtedly choose to be philosophical naturalists (and thus atheists) because they see no need to have God in their philosophical framework, but as I said in an earlier posting, others reject that option and stay religious. But this is purely a personal choice made by individual scientists and it has no impact on how they do science, which only involves using methodological naturalism. There is no requirement in science that one must be a philosophical naturalist, and as I alluded to earlier, Gaylord Simpson was not a philosophical naturalist although he was a methodological naturalist.

The question of philosophical naturalism is, frankly, irrelevant to working scientists. Scientists don’t really care if their colleagues are religious or not. I have been around scientists all my life. But apart from my close friends, I have no idea what their religious beliefs are, and even then I have only a vague idea of what they actually believe. I know that some are religious and others are not. It just does not matter to us. Whether a scientist is a philosophical naturalist or not does not affect how his or her work is received by the community.

But what the creationist/ID advocates want, according to their stated goal of “If things are to improve, materialism needs to be defeated and God has to be accepted as the creator of nature and human beings” is to enforce the requirement that scientists reject both philosophical and methodological naturalism. They are essentially forcing two things on everyone:

  • Requiring people to adopt the creationist/ID religious worldview as their own.
  • Requiring scientists to reject methodological naturalism as a rule of operation for science.

In other words, creationist/ID advocates are not asking us to reject only Darwin or to turn the clock back to the time just prior to Darwin, they want us to go all the way back to before Copernicus, and reject the very methods of science that has enabled it to be so successful. They want us to go back to a time of rampant and unchecked superstition.

This is probably not a good idea…

What do ID advocates want?

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

In an earlier posting, I spoke about how those who view Darwin’s ideas as evil see it as the source of the alleged decline in morality. But on the surface, so-called ‘intelligent design’ (or ID) seems to accept much of evolutionary ideas, reserving the actions of a ‘designer’ for just a very few (five, actually) instances of alleged ‘irreducible complexity’ that occur at the microbiological level.

This hardly seems like a major attack on Darwin since, on the surface, it seems to leave unchallenged almost all of the major ideas of the Darwinian structure such as the non-constancy of species (the basic theory of evolution), the descent of all organisms from common ancestors (branching evolution), the gradualness of evolution (no discontinuities), the multiplication of species, and natural selection.
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Evolutionary theory and falsificationism

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

In response to a previous posting, commenter Sarah Taylor made several important points. She clearly articulated the view that evolutionary theory is a complex edifice that is built on many observations that fit into a general pattern that is largely chronologically consistent.

She also notes that one distinguishing feature of science is that there are no questions that it shirks from, that there are no beliefs that it is not willing to put to the test. She says that “What makes scientific theories different from other human proposals about the nature of the universe are their courage. They proclaim their vulnerabilities as their strengths, inviting attack.”

I would mostly agree with this. Science does not shy away from probing its weaknesses, although I would not go so far as to claim that the vulnerabilities are seen as strengths. What is true is that the ‘weaknesses’ of theories are not ignored or covered up but are seen as opportunities for further research. Since there is no such thing in science as infallible knowledge, there is no inherent desire to preserve any theory at all costs, and the history of science is full of once dominant theories that are no longer considered credible.

But having said all that, it is not necessarily true that finding just one contradiction with a theory is sufficient to overthrow the theory. In the context of the challenge to Darwinian theory by intelligent design (ID) advocates, Sarah’s statement that “All that any ID devotee has to do is to show ONE fossil ‘out of place’, to prove the theory doesn’t work. Just one horse shoulder blade in a Cambrian deposit somewhere in the world, and we can say goodbye to Darwin” is a little too strong.

Sarah’s view seems to be derived from the model of falsificationism developed by the philosopher of science Karl Popper (see his book Conjectures and Refutations: The Growth of Scientific Knowledge, 1963) who was trying to explain how science progresses. Afer showing that trying to prove theories to be true was not possible, Popper argued that what scientists should instead do is try to prove theories false by finding a single counter-instance to the theory’s predictions. If that happens, the theory is falsified and has to be rejected and replaced by a better one. Hence the only status of a scientific theory is either ‘false’ or ‘not yet shown to be false.’

But historians of science have shown that this model, although appealing to our sense of bravado, does not describe how science actually works. Scientists are loath to throw away perfectly productive theories on the basis of a few anomalies. If they did so, then no non-trivial theory would survive. For example, the motion of the perigee of the moon’s orbit disagreed with Newton’s theory for nearly sixty years. Similarly the stability of the planetary orbits was an unsolved problem for nearly 200 years.

Good theories are hard to come by and we cannot afford to throw them away at the first signs of a problem. This is why scientists are quite agreeable to treating such seeming counter-instances as research problems to be worked on, rather than as falsifying events. As Barry Barnes says in his T.S. Kuhn and Social Science (1982):
“In agreeing upon a paradigm scientists do not accept a finished product: rather they agree to accept a basis for future work, and to treat as illusory or eliminable all its apparent inadequacies and defects.”

Dethroning a useful theory requires an accumulation of evidence and problems, and the simultaneous existence of a viable alternative. It is like a box spring mattress. One broken spring is not sufficient to make the mattress useless, since the other springs can make up for it and retain the mattress’s functionality. It takes several broken springs to make the mattress a candidate for replacement. And you only throw out the old mattress if you have a better one to replace it with, because having no mattress at all is even worse. The more powerful and venerable the theory, the more breakdowns that must occur to make scientists skeptical of its value and open to having another theory replace it.

After a theory is dethroned due to a confluence of many events, later historians might point to a single event as starting the decline or providing the tipping point that convinced scientists to abandon the theory. But this is something that happens long after the fact, and is largely a rewriting of history.

So I do not think that finding one fossil out of place will dethrone Darwin. And ID does not meet the necessary criteria for being a viable alternative anyway, since it appeals to an unavoidable inscrutability as a factor in its explanatory structure, and that is an immediate disqualification for any scientific theory.

Natural selection and moral decay

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

In a previous posting, I discussed why some religious people found evolutionary theory so upsetting. It was because natural selection implies that human beings were not destined or chosen to be what they are.

While I can understand why this is upsetting to religious fundamentalists who believe they were created specially in God’s image and are thus part of a grand cosmic plan, there is still a remaining puzzle and that is why they are so militant in trying to have evolution not taught in schools or its teaching to be undermined by inserting fake cautions about its credibility. After all, if a person dislikes evolutionary theory for whatever reason, all they have to do is not believe it. [Read more…]

Why is evolutionary theory so upsetting to some?

(I will be traveling for a few weeks and rather than put this blog on hiatus, thought that I would continue with my weekday posting schedule by reposting some of the very early items, for those who might have missed them the first time around.)

One of the questions that sometimes occur to observers of the intelligent design (ID) controversy is why there is such hostility to evolutionary theory in particular. After all, if you are a Biblical literalist, you are pretty much guaranteed to find that the theories of any scientific discipline (physics, chemistry, geology, astronomy, in addition to biology) contradict many of the things taught in the Bible.

So what is it about evolution in particular that gets some people’s goat?
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