Why Sciences Cannot Provide the Whole Truth

In comments to my blog on the theory of evolution and religion, it was suggested that this theory is seriously flawed but that advocates of the theory of evolution nevertheless have "faith" in it. The notion that the theory of evolution is seriously flawed gets a "Duh!" response. Of course it is. All historically grounded theories are flawed by a lack of critical data and this would be especially true of a theory that covers millions of years. Moreover every scientific theory is flawed to a point that having "faith" in any such theory in the sense Christians use the word "faith" when they speak of having faith in the truth of the Bible would be an unwarranted position to take.

There is a faith scientists typically have that research done along certain lines within the framework of some theory will result in valuable insights but that is not the same as having faith that that theory is true. And scientists and engineers and others routinely rely on results in physics in various applications, which is not the same as believing that these results are true beyond any doubt. At a web site on Celestial Mechanics it is said of a particular definition of Newton's Second Law that "... the definition is logically faulty, but can be realized with great accuracy in practice."

There are good reasons not to place too much faith in any scientific theory. Anyone who has engaged in scientific research has experienced pet hypotheses proving to be false. That alone should lead to a certain amount of skepticism. But their are deeper reasons not to place a great deal of faith in the capital "T" Truth of any scientific theory. (I now will survey some fields in which, in most cases, I have limited or even almost nonexistent expertise so please point out any critical flaws. I apologize also for the length of this blog.)

Uncertainties Associated with Measurement and Experimentation

Heisenberg's Principle of Uncertainty provides a certain insight into the limitations of empirical sciences, according to which, using the language of his 1927 paper

The more precisely the position [of a subatomic particle] is determined, the less precisely the momentum is known in this instant, and vice versa.

In fact, his principle extends to other phenomena -- to any "canonically conjugate" variables. In the case of a moving electron, these pairs of variables are momentum and position, and energy and time.

There seems always to be a certain uncertainty that arises when any event or thing is measured. If one measures the distance between points A and B representing the width of a wall and then measures a board one intends to cut to span that distance there will be an inevitable uncertainty in the accuracy of each measurement. I have done this many times and have never gotten my measurements exactly right. Fortunately, in most cases, the variation in lengths doesn't tend to be greater than a millimeter or so. But there is always going to be an error of this sort. The same appears to be true of the measurement of anything no matter how precise one's measuring instruments are.

Another difficulty with measurement is the problem that the instrument used to measure a phenomenon will normally interfere with it. A simple case of this is the use of a probe inserted from the outside of a container into that container to measure the temperature of what is in the container. I used to try to measure the temperature of coffee beans during roasting them. Inevitably the ambient temperature of the environment the roaster is in will have an effect on the temperature of the beans in the roaster because of the connection of the probe to the area outside the roaster. One can always devise better and better instruments and the conditions under which the beans are roasting to reduce the error but there will always be some error. Fortunately, it is unlikely to affect the flavor of the beans.

Many years ago, I read a number of papers on "the social psychology of the psychological experiment." One such paper exists on the web that quotes the psychologist A. H. Pierce concerning the "compliance" of subjects of psychological experiments as follows:

It is to the highest degree probable that the subject['s] . . . general attitude of mind is that of ready complacency and cheerful willingness to assist the investigator in every possible way by reporting to him those very things which he is most eager to find, and that the very questions of the experimenter . . . suggest the shade of reply expected .... Indeed . . . it seems too often as if the subject were now regarded as a stupid automaton

In fact, it is widely known that experiments on rats are so subject to experimenter bias that it is necessary to do "double blind" experiments in which the person running the experiment does not know the purpose of the experiment -- what it is testing. Double blind experiments are the norm in medical studies, as when a placebo is included along with one or more other drugs, and the person dispensing the drugs does not know which subject of the experiment is getting which kind of pill.

Uncertainties that Result from How We Slice up the Universe to do Science

How scientists slice up the world to study it will have an inevitable effect on the results. The world does not come in what we might call easily identifiable natural units. We are all taught, for instance, that plants and animals are fundamentally different yet they have some important similarities. Plants are like us in that they breathe in oxygen and breathe out carbon dioxide just as we do, and for the same reason, as is explained in In fact, " just like animals, plant cells must "burn" sugar for energy and to do that they need oxygen." This latter site goes on to say

glucose becomes the basic building block for a bunch of other carbohydrates, such as sucrose, lactose, ribose, cellulose and starch ...[and] in both plants and animals they can be used to make fats, oils, amino acids, and proteins.

Once we make a sharp distinction between plants and animals then we are saddled with the difficulty explaining how it is that both of these very different types of entities should be alike in so fundamental a way (check out this interesting site on respiration across various species of plants and animals. This is the basic conundrum that faces us when we chop up the world into studyable research areas for the purpose of doing science -- we must now explain similarities among things that we are treating as belonging different. Over the years we have chopped up the world in one way to do physics, in another way to do chemistry, and in still another way to do biology. This forced sciences to create bridges between them. The result was physical chemistry, biophysics, and biochemistry. Thus in addition to journals in chemistry, physics, and biology, we also have the Archives of Biochemistry and Biophysics.

For a fairly long time, as I noted in my blog on What is Linguistics?, linguists sharply distinguished the separate subdisciplines of phonetics, phonology, morphology, syntax, semantics, and pragmatics. Immediately this resulted in a need for such bridging fields as morphophonology ("The combinatory phonic modifications of morphemes which happen when they are combined")and morphosyntax ("The part of morphology that covers the relationship between syntax and morphology"). Closer to my own research, we find the division between the study of conventional meaning (semantics) and of how linguistic forms are interpreted in context (pragmatics) not to be as sharp as initially thought.

Uncertainties in Mathematics

I always had believed that mathematics was firmly grounded if only because it was not an empirical science. But, of course, there are proofs of theorems that are later proved to be defective. And there are theorems that have never been proved to be true. A cousin of mine doing graduate work in mathematics was, along with his classmates, given ten problems to work on over a weekend. My cousin and his wife decided to have a picnic on Sunday despite the fact that he had solved none of the problems. He ran into a fellow student at the park and found out that he had solved two problems. It turns out that these ten problems were official "unsolved problems" in mathematics. It seems that one does better work when one doesn't know how difficult a problem is.

Though I had to struggle with it as a philosophy graduate student taking a course on the foundations of mathematics many years ago, I was blown away by a proof by Kurt Godel that efforts of mathematicians and logicians to provide a solid foundation for calculus by "reducing' it to set theory will inevitably fall short because no axiomatization of set theory that can be proved to be consistent can also be proved to be complete and that the converse is true as well. I would imagine that efforts to "reduce" any science to a set of basic hypotheses would be subject to the same problem as one tries to make them ever more explicit and precise.

Tags: science, limits to knowledge