Revisiting the topic of science and proof on the tenth anniversary of blogging

Yesterday marked the ten-year anniversary of my beginning blogging. For the first seven years I wrote on my university’s blogging platform and then three years ago I was invited to join the FreethoughtBlog network. Initially I just felt the need to try blogging but was not at all sure what form the blog would take and what I would write about. But I settled fairly quickly into a rhythm and though there have been some minor changes over time, basically it has ended up as me writing about whatever I felt worth writing about at the moment, mainly to clarify my own ideas about those issues with the help of the commenters. I have been impressed with the knowledge and insights that many readers have provided.

I was curious as to how I started out and went back and looked. Here’s the very first, somewhat apologetic, post on January 26, 2005.

My own blog!

Well, here we go into the (by now) fairly well charted waters of blogdom. While I regularly read quite a few blogs written by other people, the thought of starting my own was rather forbidding for several reasons.

The first was the sheer time and effort involved to keep posting fresh entries that might draw readers.

The second was that some of the best blogs I read were by people who seemed to either have sources of information that were not readily accessible to me (such as Josh Marshall) or who had the time (like Atrios) to scour the web for interesting nuggets that were missed or ignored by the mainstream media or wrote so wittily and cleverly (like James Wolcott) that my entries would be lame by comparison.

The third was that although I have many interests and have opinions on them, there are clearly people who have deeper knowledge in each of the areas that I am interested in. So what could I contribute that could not be found anywhere else?

Well, I figure the only way to find out is to venture in and see where it all goes. So this entry is the equivalent of slowly dipping my toes in the water. Hmm, not bad so far…

After getting that out of the way, my first substantive post came the next day on January 27, and was the beginning of a trilogy that explored the nature of science that I think is worth repeating.

Science and Proof

On a plane earlier this week, I was seated next to a very nice woman and we struck up a conversation that quickly turned to religion. She was a Biblical literalist who belonged to an evangelical Christian church. In the course of comparing the scientific and religious approaches to describing the world, she made the claim that the theories of evolution and the big bang had not been “proven” and that thus they were articles of faith, just like any religious dogma.

This is a familiar argument to anyone (like me) who has been involved in the whole brouhaha about whether “intelligent design” should be taught alongside Darwinian natural selection in science classes, and it reveals a common misperception about the nature of science.

This view is not held just by religious people, it is widespread. In the first class in my course on the history and philosophy of science, I ask students how they would distinguish science from non-science and invariably they begin by saying that science consists of things that have been proven true.

But nothing, even the most robust of theories, is “proven to be true” in science. But does that mean they are pure articles of faith, on a par with religious beliefs? Surely not. Newton’s laws and the laws of hydrodynamics have not been proven true either, but the woman and I both boarded the airplane confident that the those laws would hold and that we had a very high chance of arriving safely at our destination. Are there any religious beliefs to which we would trust our lives as confidently?

Clearly, the fact that the laws of science are not proven true does not diminish their worth and validity. Thus their credibility must be based on something other than simple proof. But most teaching of science, at any level, pays little attention to this important feature of scientific knowledge. And so the public policy discussions on issues like intelligent design rarely get beyond a fairly simplistic level.

Too bad.

I followed this up with two more posts elaborating on the issue of science and proof, triggered by comments that I received to the first.. This one was on January 28.

Science and proof II

In his comment on my earlier posting on “Science and Proof”, Kurtiss Hare raises an interesting point about the value of religion and what kind of validity criteria I was referring to, so I thought I would elaborate.

When it comes to the value of belief structures to an individual, then there are really no external criteria that can be imposed. For example, for someone who has experienced a personal tragedy, a belief in God and a divine purpose for life may be of far more value than all the science in the world.

The point I was trying to muddle through to about science is that it is not being “proven true” that gives scientific theories their credibility, but the fact that they seem to work well, are reliable, and can be used to make predictions.

The probability argument that Kurtiss raises is interesting but has two directions in which it can be taken. The first (which I think is the one he makes) is that the fact that very few planes crash means that the probability of that particular application of the scientific theories (i.e., arriving safely) is high.

But does that translate into a high probability of the underlying scientific theories being true? No, because if you want to assign a “truth probability” to a scientific theory then you have to compare (for any given theory) the number of predictions that are confirmed to the total number of predictions that are conceivable. Since for any non-trivial theory the number of possible predictions is infinite, the truth probability for any theory (however “good”) turns out to be zero!

This seems paradoxical but philosophers of science have not been able to get around it.

After a couple of intervening posts, the trilogy ended with this on February 2.

Science and proof III

Dan had a comment on the “science and proof II” posting that I think is of general interest that requires a fresh posting. He asks:

“Okay, do you have a quick explanation for why falsification is not the distinction between science and religion?

On a day to day level, it works for me. If someone says there exist leprechauns, but they are invisible, and leave no trace in our world, I know that the statement can not be proven wrong so it is not worth arguing against. But if someone says that species evolve from other species, it is conceivable that it could be proven wrong, so it is worth taking seriously. And if enough people try to disprove it and fail, that is good evidence that it might have explanatory power.”

Dan’s point is a good one. At a simple level, falsificationism sounds plausible. The theory that “All swans are white” can be seemingly falsified by the appearance of a single black swan. Falsification’s appeal stems from the fact that we seem to be able to make a clean distinction between an observation and a theory.

But that distinction becomes blurred when you start looking at the kinds of things that scientists research, because then observations are no longer simple sensory perceptions. The statement “electrons exist” is not a simple observational one but requires us to use a vast array of theories from a range of disciplines in order to interpret the readings of the measuring instruments. So if the “observation” disagrees with the theory being examined, it is not clear where to place the blame. Is it on the theory being tested, or on one of the theories underlying the observations?

So in reality one is always comparing one set of theories with another set of theories and there is no rule that forces you to make a particular choice, although good taste and judgment and standard practices may lead the scientific community to a consensus decision.

The other problem with using falsification is that no theory has ever explained everything in its domain. There are always unsolved problems and contradictory results. Trying to reconcile these discrepancies serve as the basis for much research. If we applied the falsification rule strictly, then every theory we have would be falsified.

These are the kinds of things that caused falsificationism to stumble and fall.

Incidentally, even the swan example is not as simple as it looks. Defenders of the white swan theory can retain their belief by arguing that what constitutes a swan is not precisely defined and that the black creature was not really a swan, and other arguments like that. We may dismiss those arguments as silly and self-serving but they are not logically ruled out.

Warning! Shameless plug coming up!

All these issues are discussed in my book “Quest for Truth: Scientific Progress and Religious Beliefs”, published by Phi Delta Kappan Foundation in 2000.

Sometimes you go back and read stuff that you wrote long ago and you cringe because you feel that you could have done so much better now. This is my feeling with that book I plugged and I am going to write another book on the logic of science that I think deals with the issue much better. But these posts seem to hold up well after ten years, in that I am not embarrassed to read them again.


  1. dogfightwithdogma says

    Congrats on ten years of blogging. I first encountered your blog about a year or two before you joined FtB. It was then and continues to be today one of my favorites. I read it very frequently. I especially enjoy the range of topics you address. But most of all I enjoy the quality of your writing and the clarity of your thinking. Keep up the excellent work!

  2. DsylexicHippo says

    As I mentioned once before, your blog is my daily tonic. It was a serendipitous stumble that led me to a wise man from Serendip and I have been a regular since. Great stuff, keep writing!

  3. filethirteen says

    I always liked the short proof of evolution, but your points were well made and it’s great to be able to look back on your work with pride.

    Actually my own perspective on “truth”, “proof” and “belief” was enhanced by your description of quantum physics. In it, if I recall correctly, you depicted the microscopic scale as a fuzzy mess of probabilities but said (and pardon me if I’m putting words in your mouth here) that certainty (known location of objects; predicted results of reactions) increased at an exponential rate as you decreased scale. At least that’s what I took out of it, and the corollary is that you can with confidence evaluate beliefs as true, likely, improbable or false depending on the strength of the evidence for them, even if no piece of evidence is mathematically certain at the lowest level.

    Anyway, congratulations on ten years.

  4. Anton Chia says

    It is precisely because you write about what YOU find interesting that WE (the regular readers of your blog) enjoy reading your items. Please feel free to carry on as long as ever you enjoy doing it. All the best!

  5. Carl says

    Dr. Singham,

    I discovered your blog when you joined Freethought Blogs, and I have been an avid reader ever since. I really appreciate the cool, thoughtful, and reasoned approach you bring to a variety of interesting subjects. I have found it inspiring in my own discussions of issues like politics and religion.

    Thanks for the great writing you’ve published here and please keep up the good work!

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