Putnam on the philosophy of science

youtube.com/watch?v=rAP4E3EpedE

This is a 10 minute video of an interview with Hilary Putnam on his scientific philosophy.

He says some pretty interesting things about the corrigibility of science. At one point he talks about how the main theories of the 20th century - relativity and quantum mechanics - will eventually be replaced by newer and better theories, just as they replaced the Newtonians mechanics of 350 years ago. Do you agree that science is dynamic like this? Is there no such thing as a scientific theory that won’t eventually give way to a newer and better theory?

Personally, I don’t think that every scientific theory will be replaced. For example, the fact that mixing sodium and chlorine together makes salt is here to stay. But what Putnam says changes, or is most subject to change, are the “big pictures” - our most general paradigms of the nature of the universe (such as the nature of space and time, or the nature of fundamental particles, etc.). I agree with him on that one.

Also, if you’re interested in the above video, you can watch the whole series. It begins here: youtube.com/watch?v=cG3sfrK5B4E. In fact, there’s a whole series of interviews hosted by Bryan Magee. He interviews A.J.Ayers, Anthony Quinton, Hubert Dreyfus, John Searle, and several others on a variety of topics.

What Putnam is talking about there is the same thing that is discussed in this essay I keep posting. Adding Sodium metal and Chlorine gas together will result in a highly exothermic reaction that produces a salt (NaCl). We already know that. But the ‘how’ of this process is what is bound to be continually refined.

Thanks for your comment, Xunzian. I read that paper and I found this interesting:

If this quote captures the gist of the paper, then I’d say it argues something dramatically different from Putnam.

Putnam says:

His statement about the newer theories not disagreeing with Newton about the approximations of the math is a key point here, and is most relevant to the point being made by Asimov about the adjustments in the approximate curvature of the Earth per mile. Putnam is saying, in regards to the question of how the newer science conflicts with the old, that we can ignore these subtle differences because the major differences are in the “big picture”.

I see their points as essentially being the same. After all, the new advances still include and can describe what occurs in Newtonian physics but they can explain other phenomena as well and do it better.

Another example I like to use is how our understanding of ‘acid’ and ‘base’ has changed over time.

Initially, ‘acid’ was merely something that tasted sour and ‘base’ was something that tasted bitter. Indeed, the German words for ‘acid’ and ‘base’ translate as ‘sour’ and ‘bitter’. It is the same in English, but since they are latin words that were adopted into a Germanic language, we don’t notice it. But, of course, that is a very limited understanding (and it also has numerous exceptions). There are also various pH indicators that we’ve known about for a long time even if we didn’t have the pH scale.

So Arrhenius came along and figured out that acids release hydrogen ions into water whereas bases release hydroxide ions into water. This is clearly a better definition than ‘sour’ and ‘bitter’. We were getting somewhere.

But there was, of course, a problem with that definition. Many things that taste bitter aren’t simple bases with a hydroxide ion. Caffeine, for instance, is very bitter tasting and is indeed basic, but there is no hydroxide ion for it to donate. What is going on? Well, Brønsted and Lowry saw this problem and modified the definition slightly. Now acids were proton donors and bases were proton acceptors. Now caffeine makes perfect sense as a base because it has nitrogens that can accept protons. Since water is a proton and a hydroxide ion, these bases release a hydroxide ion by taking a proton away from the water! All the acids and bases that could be described by Arrhenius were included in this new mix and some new bases were included as well.

However, there were still some niggling compounds that would lower the pH of a solution that couldn’t be described by the BL definition. So Lewis took the next step and defined acids as electron pair acceptors and bases as electron pair donors. All of the acids and bases described by the BL definition and the Arrhenius definition are included in this new understanding plus some new acids and bases.

From there, other refinements have been made about various orbitals and how the molecules behave and, no doubt, further enhancements will be made.

That situations exhibits the same narrowing that Asimov talks about as well as the expansive nature that Putnam talks about. Likewise the shape of the Earth that Asimov talks about can be understood as making the theory ever more applicable as our understanding increases. Same deal with the new physics.

It’s a matter of perspective, but when you actually see the results in action, the two are in fact the same thing.

I’m not so sure that it does - but that might say something more about me and my lack of insight than it does anything else.

I think the example is a good one insofar as it illustrates Asimov’s subtle adjustments as science refines itself as well as Putnam’s corrigibility as science criticizes itself - but these corrections in the nature of acids and bases are minor. What Putnam is talking about is wholesale paradigm shifts, not minor adjustments. He seems to be saying that if science were permitted to progress indefinitely, it would eventually go through one paradigm shift after another - each one being mediated by, perhaps, hundreds of years, but each one will come to pass eventually.

Of course, you’d be right to say that Asimov can question the degree to which these paradigm shifts are wrong, but if Putnam had any say, he’d probably say that every once in a while, for the rest of the life of science, we’re going to find that we are wrong to a high degree.

But the ‘big pictures’ that Putnam are talking about are inclusive of all the information that the old picture held and come about because of subtle new measurements. New, better measurements started to suggest that Newton’s model was breaking down so they had to update the model in a fairly subtle way to account for these changes. But, of course, when the model that you are working with is the universe taking even small changes into account will be greatly magnified. Putnam’s example is grandiose because he is trying to make one point whereas Asimov’s is tiny because he is trying to make a different one. But the mechanisms at work are quite similar. The notion that the world is flat is very very different from the notion that the world is round. But Asimov didn’t deal with the conceptual shift that such a change in understanding entails.

You’re right that the differences in measurements are going to be small - what we actually observe (measure) shouldn’t be all that different, but the conceptual shift very well might be. The Copernican vs. the Ptolemaic models of the universe is a good case in point. We observe the same thing in either model when we look up at the sky at night, but we interpret what we see in drastically different ways. Einstein’s relativism is also a good example. Whereas Newton would have predicted no time dilation as one reaches faster speeds, Einstein does - but what we measure of this time dilation is going to be ever so infinitesimal at the speeds we are capable of achieving in a practical sense - which is why Newton and his contemporaries never really noticed it. Nonetheless, the re-conceptualization of the universe that this leads to is astounding.

Anyway, I’m not so sure this disagrees with your last post or paraphrases it. I guess it all depends on what we’re talking about: are we talking about our measurements of the world (which seem to change very little over the centuries) or our conceptualizations of it (which seem to change much)?

That’s why I thought that the conception of acids was relevant to the discussion. Donating an H+ or a OH- is conceptually different from donating an H+ or accepting an H+, which is conceptually different from accepting electrons or donating electrons. Those are all pretty distinct from one another, especially the last one. But in terms of what we observe, nothing really changes.

Science is a description of reality. Its based on two things obsevational evidence(the scentific method) and human concepts. Our abilties to find experimental evidence and to come up with concepts restricts how acurate science.

Sometimes evidence forces us to drop certain concepts and come up with new ones(netwon to quantum). Othertimes great insightful concepts lead us to look at the world a different way and ultimatly describe nature more accuratly or explain phenomena that were before unexplained hand(relativity/natural selection).

When we come up with the concept first and then find evidence for it then we understand the concept well. But when we are forced to give up old ideas then our cencepts become hazy…as is the case with quantum mechanics.

I thought the video was very good, agreed with it. I think that understanding in what ways nature is subjective/objective is one of the biggest questions in philosophy. ultimatly we can not solve the mind/body problem before we understand subjectivity.

I think the bit in the video about a police man standing on the corner and two different peoples subjective concepts is a deep point to be taken seriously.

Our own concepts of reality act as a filter and yet we cannot percieve without concepts(or can we???).

My view is that all concepts are limited hence no scientific theory will ever give a complete description of nature.

Put simply the universe is infinte both in externally and internally. All concepts are finte.

“If the doors of perception were cleansed everything would appear to man as it is, infinte”