Science is a method for acquiring knowledge that helps us to understand our world and everything in it. That method involves the accumulation of data, followed by statistical and other methods to interpret the data.

By writing an article on the limitations of science, I in no way mean to impugn that method, which has been essential to much of humanity’s progress since the beginning of human civilization. I have worked as a scientist for over 30 years – nearly all my adult life – and I have great respect for the previous accomplishments and future potential of science.

Probably all human beings have a strong tendency – some much more than others, conservatives much more than liberals – to think in terms of black and white, when shades of grey would be much more appropriate. This tendency is fueled by the fact that it is much easier to think in black and white terms than to think in shades of grey. With regard to science, at one extreme there are those who hold it to be infallible and that it always provides the correct answer; at the other extreme are those who, as pointed out in a recent post, believe that science is akin to a dogmatic faith based religion or that most scientists are shills whose main interest is to defend the status quo. The truth is somewhere in between those two extremes.


“Flawed” science and the limitations of experimental and observational science

So many times I have read newspaper articles in which a scientific study was criticized as being “flawed” – as if “flawed” is a black and white concept that means that the study’s conclusions are wrong if the study was “flawed” and right if the study was not “flawed”. The fact of the matter is that almost all scientific studies are flawed in some way, just as almost all human beings are flawed in some way. The question should not be whether or not a scientific study is “flawed”. Rather, the questions should be: “in what way was it flawed?; how much it was flawed?; and how are the answers to those questions likely to affect the stated conclusions?”

There are two types of scientific studies – experimental and observational. You have probably heard that experimental studies are superior to observational studies. That is true to some extent, but it is by no means absolutely true. Observational studies are those where the scientist collects data from observations of events that occur in the real world without any interventions from the scientist. Experimental studies are those where the scientist not only observes the data but influences it by means of experimental intervention. Experimental and observational studies each have their own strengths and weaknesses.

The problem with observational studies is that there are so many things in the real world that can influence outcomes (especially when studying something as complex as human behavior) that it is nearly impossible to account for them all in any single scientific study or to fully and accurately interpret their effects. For example, suppose a scientist wants to study the effects of air pollution on crime rate. It may be relatively easy to accumulate data on crime rate and air pollution and conduct statistical tests to show whether or not they are associated. But showing that they are associated is not sufficient. One must also consider the possibility that any one of numerous other variables, such as income, education, or any number of environmental factors may have been responsible for the apparent association of air pollution with crime.

Experimental studies largely get around that problem by randomly assigning an experimental intervention (for example, such as a drug for the treatment of an illness) to one group and comparing it with a “control group” that didn’t get the intervention, while taking care to ensure that other variables that might have an effect on the outcome are approximately equal in both groups. In that way one can ascertain the effect of the intervention on the outcome.

But experimental studies have their own types of problems. Consider scientific studies concerning global warming, for example. As far as I am aware, all studies on global warming are observational rather than experimental. One major reason for that is that it would be very dangerous and unethical to purposely try to create global warming for the sake of conducting a scientific experiment. But even if such an experiment was conducted, its interpretation would be problematic. What we really want to know about global warming is how it is produced in the real world – outside of the artificial circumstances of an experiment. A scientific experiment on global warming would give us very limited information on that important question.


Science as an art

Probably most non-scientists think of scientific methodology as a rigid and technical set of rules. But in point of fact, just as in art, insight plays an important role, both in the creation of scientific studies and in their interpretation.

The insight that is important to the creation of scientific studies may originate largely from other scientific studies, or it may instead originate solely from one’s personal life experiences and thoughts. One striking example of that is the story of how the chemical structure of benzene was identified largely through the inspiration of a dream. Although most scientific studies originate in a less dramatic fashion, the majority of scientific studies originate from one’s own life experiences and thoughts.

The interpretation of scientific studies, especially observational studies, is hardly ever simply a matter of merely following technical rules to come up with an answer. Rather, one must consider everything s/he knows about the subject and explore many different ways of interpreting the data, weighing the pros and cons of each, in order to best make sense of the data and arrive at a conclusion that is most consistent with it. Just as with the creation of scientific studies, appropriate interpretation of data usually requires one to consider it in the light of one’s intuition and personal experiences with the subject matter.


The problem of established paradigms – regarding the cause of obesity

A paradigm is a set of beliefs that provide a way of viewing reality with respect to a specific subject. Paradigms are useful in science to the extent that they can help in the visualization of reality. However, they can be harmful to the extent that they encourage inflexible or black and white thinking that is not sufficiently consistent with reality. Since scientists are human they sometimes have a tendency to adhere too much to certain paradigms.

When I was in medical school I was taught a very simple paradigm for the cause of obesity: It is caused by eating too many calories or too little physical activity or a combination of those two factors. End of story. It seems intuitive enough. We know that calories are converted into fat and that physical activity burns off calories. So the paradigm seemed obvious.

But I was suspicious of that paradigm because I knew people for whom it didn’t seem to apply. So I researched the medical literature on the subject and found out that the actual facts were very different from and more complicated than what the paradigm said.

The truth of the matter is that obesity is mostly genetically determined: Our hypothalamus acts as a thermostat to control our weight. People who are genetically programmed for obesity or for larger than normal body weight have a thermostat that is programmed at a high level. When they begin to lose weight, their thermostat does two things to bring their weight back up to the weight that they are programmed to: it increases their appetite in proportion to the amount of weight they lose; and it decreases their basal metabolic rate, which means that they burn off less calories than normal people both when they are at rest or when engaging in physical activity. Of course, it is possible that such people can, depending on how high their thermostat is set, and depending on how much will power they have, eat so little that they lose substantial amounts of weight anyhow. But that is extremely difficult, few obese people succeed at it, and those who do succeed usually don’t keep the weight off for very long. Of course my explanation also is an over-simplification of the facts. But it comes a lot closer to reality than did the standard paradigm.

I don’t know if most doctors still buy onto that paradigm. In any event, the question arises as to why doctors would buy into such a pattern when the medical literature on the subject clearly indicated that it wasn’t an accurate representation of reality. As I noted above, false paradigms are sometimes accepted because they seem to make sense and they are easy to believe. People – and even scientists – change their views of reality only with great difficulty. And since the paradigm was widely accepted by the medical profession, scientific articles that contradicted it were not likely to be published in the most widely read and prestigious medical journals, until more recently. But still, there was enough scientific evidence out there to make a clear case for anyone who was skeptical of the prevailing paradigm and who wanted to take the trouble to dig into it.


Intrusion of commercial interest – the effectiveness of acupuncture

The field of medicine is not only a science, but a business as well. Therefore, it shouldn’t be too surprising that business interests play at least some role in determining the prevailing paradigms among medical professionals.

Another paradigm that I was exposed to in medical school involved acupuncture. It was never mentioned in any of my classes until one day one of my fellow students asked about it in class. He was told simply that acupuncture was a quack science. End of story.

Like the obesity paradigm, I eventually became very suspicious of the idea that acupuncture is a quack science. I must admit that I never researched the subject as I did the cause of obesity. However, based on several conversations I had with people who practiced it, I came to believe that acupuncture is not at all a quack science.

My reasons are very simple. Those who told me it is a quack science never explained why they believed that. They simply implied that it is common knowledge that acupuncture is a quack science and that there is something wrong with anyone who believes differently. In contrast, those who have told me that it can be very effective for many different purposes have discussed with me a wide variety of literature that supports their views on that point.


Extra sensory perception (ESP)

ESP is a term that includes a wide range of phenomena that have in common the ability of a person to acquire information by means other than the known physical senses or the use of logic or experience. Many or most people, including many or most scientists, consider ESP to be something akin to magic – in other words, not a real phenomenon.

Nevertheless, I have long believed that ESP is a real phenomenon. Why? I believed in it not because of any scientific evidence I was aware of, but rather because of my profound awe regarding the human mind. And I did not consider my belief in ESP to be in the least bit anti-scientific. The lack of scientific proof that something exists does not by any means mean that it does not exist. The lack of scientific proof could just as well be explained by the fact that science has not looked very hard for it. Since I was aware of no scientific evidence either for or against ESP, in order to have an opinion on it I had to resort to something else. That’s not anti-scientific.

Then a few years ago I read a book that put forth a great deal of extremely convincing scientific evidence that many forms of ESP are indeed real. I don’t remember the name of the book, but here is some evidence on the subject.

Some may disparage the fact that controlled scientific experiments have shown small increases in the rates at which some people are able to ascertain the identify of playing cards that they have not seen at slightly higher rates than would be expected by chance. They might say, so what? What good can that do? What would be much more important would be to show whether people can divine really important things that have the potential to enhance or save lives. They have a good point – but only to a point, because they miss the larger point of these scientifically controlled studies. There may indeed be many people who are much more successful in using ESP powers under conditions that are really important than they are in using them under the conditions of a controlled scientific experiments. But the demonstration of such powers would require an observational study, which would present numerous difficulties if one assumes that the conditions under which ESP has dramatic uses occur very infrequently during the course of ordinary life. If that is the case the methodological difficulties could be enormous. I’m not saying it couldn’t be done – and maybe it has been done (I don’t know if it has). But my guess is that it would require a very large number of subjects, a great amount of time, and an ingenious study design.


Life of the soul after death

This is an issue that would seem almost impervious to scientific study. If the soul does continue to live after death, but it has no further interaction with the living or with the Earth, then it would indeed be completely impervious to scientific study. In order to acquire data the scientific investigator would have to die first. And then he couldn’t communicate the study results to the living. Unless…

Actually, many people have described what is sometimes referred to as “near death experiences”, where they claim that their soul travels to the afterlife and then comes back. I once talked to a fellow physician who claims to have herself experienced such an event. She was a friend of mine, and I found her account somewhat convincing. There are also several books that have been written on the subject, and I have read one of them, though it wasn’t included on this list. The book I read was written by a psychiatrist, and it seemed reasonably convincing to me. It was simply a recounting of many cases that the psychiatrist had witnessed first hand, along with his interpretations. Of course, there are other interpretations that one could put on those accounts.

But the most convincing single account of this phenomenon I ever read was from the autobiography of the psychiatrist, Carl Jung, who has sometimes been referred to as the father of psychiatry. A whole chapter, approximately one tenth of his whole autobiography, was devoted to a single incident in his life where he claims to have ascended to some heaven-like place, was told that a mistake had been made, and was sent back down to Earth, to his great disappointment. After returning to the hospital and regaining consciousness he tried to warn his doctor that his time was coming very soon. However, his doctor refused to discuss it with him and died a couple days later.

Anyhow, I believe in the permanent life of the soul after death. I don’t believe in it so strongly that I don’t have a normal fear and aversion to death. And it could be argued that I believe in it simply because I want to believe in it. I won’t argue that point.

The only point I want to make about this here is that I don’t consider my belief in this to be anti-scientific. Unlike the religious belief that the Earth is four thousand years old, for example (which my fundy nieces believe, which drives me crazy), the life of the human soul after death is something for which little or no scientific evidence exists either way. I can argue (and I do) that the near death experiences described above provide some evidence for it. Others can argue that the fact that a person expresses no emotion after he dies is evidence against it. But if the soul leaves the body after death, then the appearance of the body after death is almost irrelevant to this issue, it seems to me. Anyhow, my reasons for believing in it would make this post too long if I tried to explain it here. The only point I want to make here is that, since science doesn’t answer the question, people have to resort to other means to decide what they believe regarding this issue.


History as science and political science

I’ll finish this post by saying a few words about history as a type of science and about political science, since these subjects are most relevant to most DUers, and since I believe these subjects help make my point about the limitations of science.

History is usually not exactly regarded as a science, although it is often referred to as a “social science”. History and political science have in common with more traditional sciences the fact that they involve the gathering of data with the purpose of helping us to understand ourselves and our relationship to the world in which we live. They are different than the more traditional sciences primarily in that they pose some extremely difficult challenges in the interpretation of data. In that sense they have more in common with the other so-called “social sciences”, which present challenges in the interpretation of data mainly by virtue of the extremely complex nature of human thought and behavior.

I have often pointed out similarities between the Bush/Cheney government and Hitler’s Nazis because I believe that such comparisons are very instructive in demonstrating the dangers that we currently face. I have often been severely criticized for making such comparisons, though most DUers have agreed with me. Are such comparisons “scientific”? Well, yes and no. It’s almost impossible to utilize valid statistical analysis for such comparisons, because of limited data – though I feel certain that it could be done to some extent, with enough thought, time and effort. Naomi Wolf, in her new book “The End of America”, makes similar comparisons by referring to many Bush/Cheney policies as “historical echoes” (of the Nazi past). She notes such things as:

 a mob of young men dressed in identical shirts violently shutting down the Florida vote count in 2000
 FBI agents stopping peace activists at airports
 The promise that upon our invasion of a country that posed no risk to us we’d be greeted as liberators
 Speaking of our country as “the Homeland”
 The requirement that doctors provide confidential medical records to government agents upon request
 The extraordinary efforts of Bush and Cheney to create propaganda disguised as news
 The paying of informers to catch “terrorists”

She ends that discussion by saying:


We point to numerous similarities between what Bush and Cheney have done in comparison to what Hitler and his Nazis did. Critics of this line of reasoning point to the differences. Admittedly, there are differences. Which is more important, the similarities or the differences? There is no obvious and certain scientific way to answer that question. I – and many others – believe that the similarities are more important in this case. In the absence of statistical proof we use our intuition, our logic, our knowledge of history, and what we sometimes refer to as “common sense”. We can’t prove that the danger is comparable. And yet it seems to us that the similarities are so striking that one would be a fool not to recognize that our country is in a grave crisis that very well could mean the end of our country.