Thursday, March 19, 2009

The Philosophy Ceiling

I like philosophy as much as the next guy, assuming the next guy is not an actual philosopher, in which case I top out well short of him. The problem of induction provides a clear enough case in point. An actual philosopher, Chris Hallquist, sets up the problem by summarizing its most famous formulation:

David Hume, possibly the most famous empiricist ever (though he’s got competition from John Locke), thought that because empiricism is true, induction can’t be justified, and since induction can’t be justified, we can’t know things like “the sun rises every day,” and the therefore we can’t know things like “the sun will rise tomorrow.” Other philosophers, such as Laurence Bonjour, have reversed the argument: if empiricism were true we couldn’t know that the sun will rise tomorrow, but plainly we can know this, so empiricism is false. ...

Hume put it this way: “all inferences from experience suppose, as their foundation, that the future will resemble the past.” This is no conceptual truth, since we can conceive of the future bearing no resemblance to the past. But it can’t be known by experience, either: “It is impossible that any arguments from experience can prove this resemblance of the past to the future; since all these arguments are founded on the supposition of that resemblance.” To prove “this resemblance” by experience, then would be circular reasoning.
It's possible to see this problem as a genuine one so long as the emphasis is laid in the right places -- we do not know the future will resemble the past.

Fair enough, but here enters the topping out: I don't need to know the future will resemble the past. If my view of the future has to be narrowly construed as supposition rather than knowledge, I can live with that. I actually think it's a reliable inference, sturdier than mere assertion, based on the sheer volume of observational data behind it -- we have, as a species, charted day after day and instance after instance in which the sun rises in the morning, the billiards balls move when struck in certain ways, the tides ebb and flow, touching fire causes pain, and so on.

Hume himself resolved the matter with what amounts to a rolling of the eyes and a shrugging of the shoulders, as summarized on wikipedia:
Rather than unproductive radical skepticism about everything, Hume said that he was actually advocating a practical skepticism based on common sense, wherein the inevitability of induction is accepted. Someone who insists on reason for certainty might, for instance, starve to death, as they would not infer the benefits of food based on previous observations of nutrition.
After that, as I picture it, he blew out the candle in his dank little room and went outside for a few rounds of ultimate frisbee, or the equivalent for 18th century Scotland, homoerotic swordplay and binge drinking. I can relate.


Anonymous said...

You're right about Hume. Hume's argument is pretty dang sound but he didn't let it freak him out. We can't say the same for Kant however -- who was so freaked out by the inescapable truth of Hume's conclusion that he started writing and didn't stop until he had cranked out the 800 page "Critique of Pure Reason", which is one of the most important works in Western Culture.

Dale said...

Anon., Yes. Good point about Kant. David Hume really gave him an interesting life, didn't he?

Jonathan said...

This reminds me of what I thought while reading Hume: "You know, he's probably right, but I don't give a shit." That's not a criticism of Hume, just an acknowledgment that we're going to go on living our lives despite our acceptance of Hume's skepticism, just as he did (and boy did he ever!).

Unfortunately, the point where we do start to care is the infamous demarcation problem, which has yet to be resolved. It's one of my main interests as a Philosophy student because I care deeply about distinguishing between science and pseudoscience.

Adam said...

Some good points. Have you read any Thomas Reid? What you wrote reminds me of him quite a bit.

Dale said...

Adam, I have not read any Thomas Reid directly, but I've read a little of him in passing. It will reveal my schizophrenia on all this to note that I am skeptical of common sense just as I am skeptical of the higher-flown philosophical challenges to it, but there it is.

Jonathan, I'm with you -- the demarcation problem is a very important one. Science must be defended and bullshit must be assaulted. I associate it more with Karl Popper, but yea, Hume is relevant to it.

Anonymous said...

A Philistine such as your humble commenter here might very well say that it is a waste of high intellectual gifts to include such non-issues as whether the sun will rise tomorrow in a philosophical argument/disquisition.

As I said in a recent post, I do not "believe" the front door of my house exists and will be there when I go to that location. I go, it is there. That is the extent to which stuff likes this requires the use of my brain cells, is it not?

Jonathan said...


I used to think the same thing about Philosophy until I took a couple of electives (I changed my major four times in the course of my lengthy undergraduate career). In fact, I couldn't stand Philosophy students, who are a trial to discuss just about anything with, but since I'm currently a Philosophy student in my last year, I guess I can't say that anymore.

Anyway, the big questions, like whether or not we can have any confidence about the Sun rising tomorrow has implications which you might care about with regard to smaller issues. I'll explain, but like most Philosophy students, it will take me a while to get to my point (and I might not even manage to make it).

We of course believe with a high degree of certainty that the sun will rise tomorrow, but how do we justify that? It's logically possible that the sun might not rise tomorrow, and we certainly can't depend on the notion that the future will always be like the past, so we've killed two important parts of our justification process: reason via logic and experience.

Scientists, just like the rest of us, depend on causal relationships, but for Hume this belief is unjustified. So, where do we go from here? What are the consequences of this thought experiment?

Hume's conclusion is that our causal reasoning is based on habits and customs. This is a problem because it seems to directly attack science's claim to specialness (is that a word?). If all of the predictions we make in science are based on an unjustified belief in causal relationships, then isn't science just like any other ideology or belief system? This is where postmodernism inserts itself into the discussion: science is socially constructed. Like religion, it's just another way of talking about the world.

I of course don't believe this for a second, but it is a problem, especially when we look at the history of science. Kuhn enters the picture with his scientific revolutions, demonstrating that our social institutions, like religion, politics, etc., play a role in shaping science. Other philosophers and historians of science point out that the criteria we use today to determine what is and is not science is also context specific, and that what was considered science a few hundred years ago doesn't look much like science today. This may seem like common sense to you, but it trips people up who think that science is a constant accumulation of knowledge and that our theories just improve as we learn more about the world. A historical analysis shows us that this isn't the case, that sometimes great science is lost, buried, and suppressed. The best theory doesn't always win. Look at the history of plate tectonics for an example of how messy, inconsistent, and childish scientists can be.

Opening this door allows people like Intelligent Design proponents to make some interesting arguments. Thankfully, most of them don't make sophisticated arguments because they don't know much about science or its history, but if they investigated the issues more thoroughly, they'd come away with some material that could cause harm. Take for example Popper's falsifiability criterion. While falsifiability is interesting and certainly useful, it's not rigorous enough and it doesn't address how scientists actually do science.

Some ID statements are actually falsifiable, and in the case of real science, not all of the concepts in our theories are falsifiable. All of this is of course assuming that falsifiability is important, but we never test a hypothesis in isolation, so an observation that contradicts the hypothesis in question doesn't necessary disconfirm it. There are background assumptions that we often don't bother to look at more closely. Take for example planetary motion. If we go back in time to say ancient Greece, astronomers believed that the earth was the center of the universe and they came up with VERY sophisticated arguments to support that view. Even when they discovered that Mars displayed retrograde motion, they were still able to work that into their theory. Check out the stellar parallax test for more information. What happened to falsifiability?

Anyway, I'm rambling. My point is that big thought experiments like Hume's sunrise have serious consequences even if they're not immediately obvious. Take for example the thought experiment that there is no absolute morality. That doesn't mean that we're going to go around killing one another, or otherwise impact how we live our life, but if you try to justify something on moral grounds, you're eventually going to hit a wall. How do you avoid moral relativism? That's what philosophy does. It asks big questions and leaves other people to clean up the mess. :)

Dale said...

Jonathan, I appreciate the comments. When you bring up the everyday methods of everyday scientists, you point up a disconnect.

Everyday science is not bogged down with the problem of induction or the finer flaws of Popperian falsifiability. No matter how much Hume they might have read, I really don't think scientists spend a lot of time gazing wistfully out windows wondering if today's patterns of cause and effect will repeat tomorrow (or, for that matter, on whether the sun will rise again).

Maybe I should apply proper Humean skepticism and wonder if, starting tomorrow, every lab in the world will come to a halt over these questions tomorrow morning. ;-)

Likewise, if presented with an hypothesis based on the workings of undetectable jinns or fairies, they don't fret over the criticisms of Popper as they dismiss such as unhelpfully unfalsifiable.

This is not to say they've solved these problems. They remain genuine problems. But I think they set them aside using nothing more ambitious or rigorous than "playing the averages" -- the sun will rise tomorrow because it has risen every morning since people began taking records of it.

At some point it becomes perverse to proceed through the world as though we don't know if the sun will rise tomorrow or if vaccines cause autism or if dead people stay dead or if prayer redirects the flow of lava. That perversity becomes outright bad faith when faith-drunk and postmodernist types use these as a wedge into which to shove the claim that science is just another "discourse."

In science, we have the best way yet developed to produce reality-tracking, verifiable, building-block-worthy answers to questions. Absolute certainty of the sort that would pass the tests of the strictest philosophy is out of reach.

It does not follow that anything at all can be shoved into the gap between good-enough-for-science knowledge and good-enough-for-philosophy knowledge. (And I recognize that you are not making a contrary claim. In fact, I don't read us to be disagreeing at all.)

Thanks. I will stop blabbering now.

Jonathan said...
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Jonathan said...

You're right, these issues are not normally of concern to most scientists. The exceptions might include working scientists who have a background in philosophy (there are a few of them) or scientists that have also transitioned into roles outside of the "laboratory" such as Richard Dawkins. Dawkins is intimately familiar with these issues, as was Gould, and to some extent, Feynman. (I put laboratory in scare quotes because I'm using it as a metaphor for the kinds of work that we associate with scientists.)

I'm actually pretty comfortable living with uncertainty, and I agree with you about the importance and value of science, though I'm not sure that philosophy is in search of absolute certainty. That's a separate issue I think that what we're discussing, though I understand how you arrived at that. Philosophy is a bit more complicated than that. Besides, saying that science makes no claims to absolute certainty doesn't really satisfy the anti-science people.

People from other disciplines such as the social sciences and even the arts have recognized in the last decade or so that there's money to be had if you can label what you're doing research or science. Some of what social scientists do, for example, doesn't really sound like science, such as some types of Ethnography, but if a researcher can give the appearance of doing science (I'm simplifying this for the purpose of discussion), they can get access to different funding opportunities. The same goes for artists, who have just recently caught on to this strategy. A lot of the funding areas for artists have dried up, but if a painter can justify their work as research ... well, you get the idea. This helps to convince some people that science is just another discourse, even though we both know that it's not.


A report was issued in 2007 suggesting major changes to New Brunswick, Canada's post-secondary education system, including turning the university campus into a polytechnic. Part of this transition would involve taking the responsibility of determining educational policy out of the hands of academics and placing it in the hands of business people, the goal of which was to focus on "'just in time' technical training programs to satisfy short-term labour market needs." So what, right? Well, unfortunately, this would involve drawing distinctions between pure and applied sciences. You see, investing in the so-called applied sciences can be justified because it apparently leads to technology, but who needs those pure science people?

How do these pure scientists go about justifying their continued research funding in this kind of climate, especially when the "enemy" is mentioning books like "The Economic Laws of Scientific Research"? According to the author of this book, technological progress is not attributable to science, and "academic science" is essentially irrelevant.

Scientists aren't always the best at defending themselves. I'm not suggesting that they read Hume, but for those of us that are interested in educating people about science or at the very least defending science, it could be important. Ignoring or dismissing the problem doesn't persuade the anti-science types, and it doesn't help us defend science's role in our society. It would be nice if scientists could just be left alone to do their work, but it is not as privileged as it once once. The barbarians are at the gate, so to speak.