Looking closely at scientific history

Since I started looking more closely into the history of science, there are two things that I have learned that I have recast into principles.

The first is that the more closely we examine important historical events in science, the less resemblance they bear to the popular condensed capsule versions that are learned in school or college or portrayed in the popular media. The earlier posting about Columbus and the flat Earth is a case in point.

The second principle is that while science textbooks are usually good for teaching the current principles of science, they tend to be bad for teaching anything about the history of science or the nature of science. In those cases, what they usually describe is better described as folklore rather than history.

Take for example one of the most famous of all scientific revolutions, the one associated with Copernicus. The popular version of this story goes as follows:

The ancient Greeks, while pretty good at mapping the stars and motion of planets, tended to create models of the universe that were strongly influenced by religious, philosophical, and aesthetic considerations, rather than on observation and experiment. Hence they came up with the idea that the Earth was the stationary center of the universe (which pleased those religious people who wanted to give pride of place to the home of God’s greatest creation – human beings) and that the stars and planets were embedded on the surface of a sphere that rotated around the Earth in circles, which pleased those philosophers with highly refined sensibilities who felt that since the circle and sphere were the most perfect geometric shapes, they had to play a central role in the cosmos.
[Read more…]

The myth about Columbus and the shape of the Earth

In his April 3, 2005 New York Times column called It’s a Flat World, After All, Thomas Friedman begins:

In 1492 Christopher Columbus set sail for India, going west. He had the Nina, the Pinta and the Santa Maria. He never did find India, but he called the people he met “Indians” and came home and reported to his king and queen: “The world is round.”

This is just a throwaway anecdote, to set the frame for another of Friedman’s typical banal outpourings of conventional wisdom. (Sorry to offend the many Friedman fans that are out there but I have never understood his appeal. Not only does he not seem to have any original insights but he also comes across as patronizing and condescending, especially towards the people of other countries.)
[Read more…]

What do creationist/ID advocates want-III?

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 not 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.

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?

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.
[Read more…]

Evolutionary theory and falsificationism

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 Darwinâ€? 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. After 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 scientific 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

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?

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?
[Read more…]

Can we ever be certain about scientific theories?

A commenter to a previous posting raised an interesting perspective that requires a fresh posting, because it reflects a commonly held view about how the validity of scientific theories get established.

The commenter says:

******
“A scientist cannot be certain about a theory until that theory has truly been tested, and thus far, I am unaware of our having observed the evolution of one species from another species. Perhaps, in time, we will observe this, at which point the theory will have been verified. But until then, Evolution is merely a theory and a model.

While we may have the opportunity to test Evolution as time passes, it is very highly doubtful that we will ever be able to test any of the various theories for the origins of the Universe.�
******

I would like to address just two points: What does it mean to “test� a theory? And can scientists ever “verify� a theory and “be certain� about it?
[Read more…]

Wanted: “Godwin’s Law”-type rule for science

Mike Godwin coined a law (now known as Godwin’s Law) that states: “As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one.�

This makes sense. As the discussion drags on, people start running out of fresh or relevant arguments, begin repeating themselves, lose their tempers, reach for something new to say, and Hitler/Nazi comparisons inevitably follow.

But Godwin”s Law has been extended beyond its original intent and is now used as a decision rule to indicate that a discussion has ceased to be meaningful and should be terminated. In other words, as soon as the Hitler/Nazi comparison is brought into any discussion where it is not relevant, the Godwin Rule can be invoked to say that the discussion is over and the person who introduced the Hitler/Nazi motif has lost the argument.
[Read more…]

Evolution III: Scientific knowledge is an interconnected web

In an earlier posting, the question was posed as to whether it was intellectually consistent to reject the findings of an entire modern scientific discipline (like biology) or of a major theoretical structure (like the theory of evolution) while accepting all the other theories of science.

The short answer is no. Why this is so can be seen by examining closely the most minimal of creationist theories, the one that goes under the label of ‘intelligent design’ or ID.

ID supporters take great pains to claim that theirs is a scientific theory that has nothing to do with religion or God, and hence belongs in the school science curriculum. (This particular question whether ID can be considered a part of science or of religion will be revisited in a later posting. This is becoming a longer series than I anticipated…)

ID advocates say that there are five specific biochemical systems and processes (bacterial flagella and cilia, blood clotting, protein transport within a cell, the immune system, and metabolic pathways) whose existence and/or workings cannot be explained by evolutionary theory and that hence one has to postulate that such phenomena are evidence of design and of the existence of a designer.

The substance of their arguments is: “You can claim all the other results for evolutionary theory. What would be the harm in allowing these five small systems to have an alternative explanation?�

Leaving aside the many other arguments that can be raised against this position (including those from biologists that these five systems are hardly intractable problems for evolutionary theory), I want to focus on just one feature of the argument. Is it possible to accept that just these five processes were created by a ‘designer,’ while retaining a belief in all the other theories of science?

No you cannot. If some undetectable agent had intervened to create the cilia (say), then in that single act at a microscopic level, you have violated fundamental laws of physics such as the law of conservation of energy, the law of conservation of momentum, and (possibly) the law of conservation of angular momentum. These laws are the bedrock of science and to abandon them is to abandon some of the most fundamental elements of modern science.

So rejecting a seemingly small element of evolutionary theory triggers a catastrophe in a seemingly far-removed area of science, a kind of chaotic ‘butterfly effect’ for scientific theories.

Scientific theories are so interconnected that some philosophers of science have taken this to the extreme (as philosophers are wont to do) and argued that we can only think of one big scientific theory that encompasses everything. It is this entire system (and not any single part of it) that should be compared with nature.

Pierre Duhem in his The Aim and Structure of Physical Theory (1906) articulated this position when he declared that: “The only experimental check on a physical theory which is not illogical consists in comparing the entire system of the physical theory with the whole group of experimental laws, and in judging whether the latter is represented by the former in a satisfactory manner.� (emphasis in original)

Of course, in practical terms, we don’t do that. Each scientific subfield proceeds along its own path. And we know that there have been revolutions in one area of science that have left other areas seemingly undisturbed. But this interconnectedness is a reality and explains why scientific theories are so resistant to change. Scientists realize that changing one portion requires, at the very least, making some accommodations in theories that are connected to it, and it is this process of adjustments that takes time and effort and prevents trivial events from triggering changes.

This is why it usually requires a major crisis in an existing theory for scientists to even consider replacing it with a new one. The five cases raised by ID advocates do not come close to creating that kind of crisis. They are like flies in the path of a lumbering evolutionary theory elephant, minor irritants that can be ignored or swatted away easily.

Extra note:

For those of you interested in this topic, the Cleveland Museum of Natural History is having an all day symposium on “Teaching Evolution and the Diversity of Life� on Saturday February 12. I am one of the speakers, speaking on the topic “Science and Intelligent Design� in classroom C from 9:45-10:45. Unfortunately the symposium is not free except for the 4:30 pm talk by Dr. Brian Alters.

The Plain Dealer ran a news item about the symposium and related topics in the Metro section yesterday (Thursday, February 10, 2005).