Evidence and Dogmatism

http://imgur.com/gallery/1BXxi

Week 7: Case Study for the Demarcation Question

Next week we’ll begin to consider the falsification model of science as a way of defining what science is. As you might expect, given the worries about falsification as a methodology for science, it doesn’t fare terrifically well as a demarcation criterion. But it’s important to see clearly why. Notice that falsification’s not being a great way of doing science doesn’t automatically entail that a necessary condition of a theory’s being scientific is that it’s falsifiable (of course, we might want to also have sufficient conditions — but it would be important enough to identify some features that scientific theories must have). This is how falsificationism came to be treated — even by Popper. Judge Overton used it this way in his (1982) opinion in McLean v. Arkansas Board of Education.

This is one of the things that worries Laudan. There are number of levels to the concern. For one, it’s not clear that creationism is not falsifiable; for two, it’s not clear that any theories (scientific or not) are falsifiable in the sense that Overton and other enthusiasts envision. And there are other concerns that shed some light both on the 1980s debate about scientific creationism (which fizzles today) and on his view of the nature of science. His debate with Michael Ruse, a philosopher of biology who testified in McLean, is the reading for Tuesday. 

On Thursday, we’ll leap into the present by considering the status of intelligent design (ID) viz. the demarcation question. The recent trial in Dover, PA shines another public spotlight on the philosophy of science. And as before, many defenders of evolution by natural selection want to make a case for ID as non-science. But how good is this case?

Tuesday (10/4): Philosophy of Science in the Courtroom

• Readings from Thursday 9/29: Popper vs. Kuhn [PDF]

• Laudan, “Science at the Bar — Causes for Concern” and Michael Ruse, “Pro-Judice” [PDF]

Questions: (respond to one — questions from 9/29 are also fair-game)

1. One might have the following reaction to Laudan’s commentary on the Overton decision: as long as the correct answer was reached, why should we worry too much about how it was reached it. How might one respond to this reaction?
2. As Laudan shows, there’s a sense in which falsifiability is an extremely weak requirement. But as we’ve already seen, there’s another sense in which it is a very strong requirement. How could this be?! Isn’t this the same as the porridge being both too hot and too cold?
3. Consider Ruse’s third objection to Laudan: that his conclusions and strategies “are simply not strong enough for legal purposes” (20). Evaluate this objection. 
4. Whose position do you find to be stronger: Laudan’s or Ruse’s? Explain your evaluation.

Thursday (10/6): The Intelligent Design Challenge

• Kitcher, "Disinterring Darwin" [PDF]

Questions: (respond to two)

1. Why do you suppose Kitcher draws a distinction between “the architects of intelligent design theory” and those who “rally to their cause”?
2. In what way(s) does the development of intelligent design (ID) in the wake of widespread abandoning of creation science connect with the claims of Laudan and Ruse?
3. Given what Kitcher says about ID, do you think he would side with Laudan or Ruse?
4. Briefly explain how Kitcher proposes to respond to intelligent design.
5. Describe the differences between the three varieties of Darwin-detractors.

Feynman on Philosophy of Science

http://evolvingthoughts.net/2010/12/attacks-on-philosophy-by-scientists/

http://evolvingthoughts.net/2011/09/more-feynman-on-philosophers/

Second Box Project Report and Presentation

Your intermediate research report and presentation for the box project are coming up, so hopefully your group has been working steadily and effectively at answering The Question. Please find details about what is expected for these assignments here and let me know if you have any questions.

The Science of Creativity

On October 4th, the popular science writer Jonah Lehrer (who has done a lot of work documenting studies of creativity and decision-making) will be giving a talk on campus as part of the Bucknell Forum "Creativity: Beyond the Box". 7:30 in Trout Auditorium (Vaughan Lit Building).

This topic is obviously relevant to our discussion of the role that creativity plays in science. I've put a series of papers on this topic (including a few by Lehrer and a draft by yours truly that I'm not sure how to finish) in our Moodle site in case you'd like to read more on this.

See John Hunter's write up on Lehrer here.
Lehrer's blog for Wired is here.

Week 6: The Darwinian Model of Science: Or, How I Learned to Stop Worrying and Accept Inductive Skepticism. . . .

Before turning to Popper's “Darwinian model” of science, I want to begin our next class by briefly talking about Goodman’s “New Riddle of Induction”. Let me contextualize this important contribution a bit here so I can lecture to you less on Tuesday. So . . . we have this problem justifying inductive inference. It seems that we cannot show that it is a reliable form of inference (any more than I can show you that I am telling the truth by merely proclaiming “I’m telling the truth!”). That might not give us reason for doubting its reliability — or suspecting that we’d be better off with other inductive methods —, but it’s disquieting nonetheless. At this point, Goodman comes onto the scene, points out that attempts to solve the justificatory problem have a certain air of pathetic desperation (my phrase) about them (p. 61), and proposes to dissolve the problem rather than solve it. He writes:

Come to think of it, what precisely would constitute the justification we seek? If the problem is to explain how we know that certain predictions will turn out to be correct, the sufficient answer is that we don't know any such thing. If the problem is to find some way of distinguishing antecedently between true and false predictions, we are asking for prevision rather than for philosophical explanation. (Goodman 1983, 62)

Here’s where he makes the comparison between justifying induction and justifying deduction (see Foster p. 15 on this general strategy). “Principles of deductive inference are justified,” Goodman says, “by their conformity with accepted deductive practice. Their validity depends upon accordance with the particular deductive inferences we actually make and sanction” (63). In other words: rules of deductive logic are sanctioned only by the fact that they give us the results that we expect from them! Isn’t this circular!? Yes, “but this circle is a virtuous one” (64). So goes the thought. These are deep waters.

But suppose that this is on the right track. . . . The question then becomes What are the rules of inductive inference? Well, this is the problem of describing (rather than justifying) inductive inference. And as we’ve seen, it’s pretty hairy. The Hypothetico-Deductive model faces the “Tacking Problem”, the Instantial Model faces the “Ravens Paradox” . . . and yet these both seem like decent descriptions of how inductive inference operates in science. Scientists very commonly take instances of a generalization as supporting (confirming to at least some degree) the truth of that generalization. Observing that the consequences of our hypotheses are in fact borne out does seem to lend support to those hypotheses. Goodman’s “New Riddle” (see in particular §4 of his chapter) is another, arguably deeper puzzle about the instantial model. But it turns out to be one that has suggested new directions for addressing the justificatory problem in a more robust way — a subject we will return to later in the course once we have a bit more conceptual apparatus built up. . . .

But for the bulk of next week we will consider the perspective of Karl Popper — arguably one of the two most influential philosophers of science, the other being Thomas Kuhn — on two issues. The first issue (for Tuesday) pertains to the philosophical trauma we’ve so far endured on the justificatory problem of induction. Suppose neither the purported solutions nor Goodman’s dissolution satisfy us. What would happen if we just accepted the conclusion? This is Popper’s move. He writes: “My own view is that the various difficulties of inductive logic here sketched are insurmountable” (Popper 1959, 6). 

Now shouldn’t this just scuttle science once and for all? Isn’t science up to its neck in induction? If what I claimed before about the triviality of deductive logic is right, wouldn’t this make science a trivial enterprise? Popper’s clever idea is to articulate a deductive model of theory testing. We can never confirm scientific theories (even in the weak sense we’ve been considering). What scientists do is attempt to falsify theories. And as we’ve seen, this is apparently a deductive business. If my hypothesis H implies that I should observe O, then if O is not observed, I know as a matter of deductive logic that H is false. Suppose now that I have a range of hypotheses: H1, H2, H3, . . . . If I falsify all but H1, what am I going to do? Probably pursue H1 a bit more — not in an effort to confirm it, but in more and more stringent attempts to falsify it. If I fail, time after time, Popper says that we should think of this theory as “corroborated” (rather than confirmed). So the model of science resembles natural selection: theories are proposed like mutations; then testing weeds out the less fit theories. We cannot say what remains is true, but can we not place more faith in it?

There are a number of worries about this approach, however. One we’ve already gestured to: the Duhem-Quine problem. Another is articulated in the optional paper by Wesley Salmon: what is it to “corroborate” a theory? Does a well-corroborated theory license any predictions? If the answer is ‘no’, then don’t we still have a problem?

The second issue (for Thursday) is whether Popper’s focus on falsification will allow us to answer a tricky question that we’ve been conveniently avoiding so far: What is science? Is it possible to decisively separate science from non-science or pseudo-science? We’ll continue discussing this issue in the context of important social issues in week 7 when we discuss the evolutionism/creationism/intelligent-design controversy as a case study. In that case, what we see is philosophy of science being played out in the courtroom!

Tuesday (9/27): The Evolutionary Model of Science

• French, pp. 49–59

• Popper, selections from The Logic of Scientific Discovery [PDF] ← Note that this was optional reading from (9/15); it is required for this class, however.

• Salmon, “Rational Prediction” [PDF] *


Questions: (respond to one)

1. Attempt to explain in your own words how Popper proposes to do science without induction.
2. Why does the Duhem-Quine thesis (discussed in French, pp. 47–48) pose a problem for his “Darwinian model” of science.
3. Consider Lakatos’s objection (quoted in French, pp. 58–59): “There is no falsification before the emergence of a better theory.” How might Popper respond to this objection?
4. Salmon asks of Popper’s account why it should give us a guide to “rational prediction”. What is Salmon’s criticism here? *

Thursday (9/29): Falsification as Demarcation

• Popper, "Conjectures and Refutations" 

• Kuhn, "Logic of Discovery of Psychology of Research" [PDF] <— This single file contains both articles.

Questions: (respond to one)

1. At first glance, it might seem like a good thing for a theory to have a great deal of “explanatory power” or receive a lot of experimental/observational verification. Why does Popper think that it’s not (necessarily)?
2. Suppose that you are a proponent of one of Popper’s pseudoscientific fields. Explain two distinct ways in which you might respond to Popper’s verdict about the value of your chosen field.
3. Describe Kuhn’s criticism of Popper’s theory of demarcation.

Follow-up Questions for Induction

I want to start class next time by considering some of the proposed solutions to the justificatory problem of induction. I will then run you through the Ravens paradox quickly (since it's in a way not so dissimilar to the problem facing H-Dism) and start on Goodman's "New Riddle". So no further reading is assigned for Thursday. However, you will probably get more out of our discussion if you read the optional articles from last time.

Here are some additional questions to think about and/or write on (if you have not done an SWA yet for this week). (Write on one:)

• Foster compares two strategies for responding to the justification problem: saying something about the meaning of 'rational' and questioning the legitimacy of the challenge (see pp. 13–15). Explain this difference.
• Devise an analogy that helps to illustrate the justificatory problem of induction. 
• If you've read the Godfrey-Smith reading: try to explain I.J. Good's solution to the Ravens Problem.
• If you've read Goodman: explain why "grue" emeralds are a problem for the instantial model.

Another Plug for Nature Podcasts

I mentioned the Nature Podcasts already in the Links/Resources page of this blog, but I want to give them another plug. I recently caught up with the two most recent episodes (I listen while mowing my lawn, typically, and can get through two) and was especially intrigued. Among other things, there were stories about the evolutionary puzzle of cockiness (i.e., overestimating one's capabilities), a theory about how plate tectonics might have gotten kickstarted by meteors, and Italian scientists being charged for manslaughter for failing to predict an earthquake!

<Steps onto soapbox> I think it's especially important for young scientists in training (like many of yourselves) to not only learn textbook science, but to stay abreast of new developments. Spending 25 minutes a week getting the Cliffs-notes version of one of the most high-profile generalist science journals read to you, isn't a bad way to start. </Steps off soapbox>

And if you want to listen to it while mowing my lawn, that can be arranged too — I'll even lend you my iPod. . . .

Week 5: Problems of Induction

We will continue our discussion of the problems of induction next week, starting class on Tuesday by making sure we are clear about the argument for inductive skepticism, its importance, and some of the potential responses to it discussed in Foster (please bring that reading again). I expect to spend most of our time on Tuesday talking about the justification problem and potential solutions.

As I mentioned, it turns out that justifying our inductive practices is only half the battle. Even describing them seems challenging. This was roughly the problem we faced with H-Dism: the simple formulation of that method seemed vulnerable to technical objections. It turns out that there are general worries about our ability to describe our inductive practices. We’ll discuss two: Goodman’s “New Riddle of Induction” and Hempel’s Ravens Paradox. I expect to only get to the Ravens Paradox on Tuesday — we’ll save the “New Riddle” for Thursday. Note that while the Goodman reading is optional, it is great. That is not to say that the ideas are easy: but it’s definitely worth reading (if nothing else than as an example of lovely, simple prose). 

Reading for the Week: (Good thing I scheduled Thursday as a day for “breathing room”!)

• Goodman, "The New Riddle of Induction" [PDF]*

• Lipton, "Induction" [PDF]

• Godfrey-Smith, "The Ravens Problem" (§3.3 from his Theory and Reality)*

Questions: (respond to one; I’ll post more questions for Thursday that arise from our discussion.)

1. According to Lipton, what is “underdetermination”? How does it play a role in arguments for inductive skepticism?
2. Is the inductive skeptic trying to show that the inferences we often make in science are bad or that we need new methods for making inductive inferences? If not this, what is the inductive skeptic trying to do? Explain the intended conclusion of the inductive skeptic’s argument. How damaging is this conclusion.
3. Explain clearly what the difference is between the descriptive and justificatory problems of induction.
4. Lipton’s statement of the Ravens Problem for the Instantial Model is brief. But see if you can piece together the argument more specifically. 

The Box is Now Available

The Mystery Box is now available for "check out". It will live on the counter below the mailboxes in the main philosophy office, Coleman 69. There is a sign-out sheet for it on my office door. Please indicate when you took it and when you expect to bring it back (so that the other group can plan accordingly). Feel free to make handoffs directly in class. Civility would suggest that you shouldn't monopolize the box.

Remember: your first project report/presentation will sneak up on us faster than we're expecting: October 6th. It be good to have something to report on then.

First Essay Assignment Posted

As you'll recall, there will be three essays assigned throughout the course. They are designed to build on one another. This first assignment will focus developing your ability to clearly (but briskly) introduce a philosophical position to a general audience. The second will focus on analyzing and critiquing an argument. The final (research) essay assignment will aim to synthesize these skills as well as give you the opportunity to carve out your own position on a topic you find particularly interesting. 

Here is the first essay assignment. Papers are due via email by 11PM on the 29th of September. They will be assessed on this rubric (other assignments will modify this rubric according to their specific goals). Notice that in order to get an 'A' on this paper, you will need to do most things very well. This will probably be difficult at first. Don't worry: it often takes a few tries to develop these skills. That's why I have set up the course to allow you to rewrite and count only your best work toward your final grade.

As I mentioned on the assignment sheet, my website has some writing advice and resources. Most of what I say there focuses on essays with theses supported by arguments. Since this is not the skill we're focusing on at this stage, it won't necessarily all apply. This time out, I want you to focus on clarity and simplicity of exposition (since that is a crucial stepping-stone to good analysis and argument). On this front, I want to highlight two especially relevant resources: Jonathan Bennett and Samuel Gorovitz's paper “Improving Academic Writing” and Peter Smith's “Developing a Writing Style”. Both stress the importance of simple, plain writing and offer some pointers on how to achieve it. One humiliating but astoundingly useful technique both mention involves reading your paper aloud (or better: having it read to you) and then rewriting. Try it and be amazed and humiliated — and a better writer. Another piece of practical advice (that I always heed): write many drafts. My writing only gets good when I write a lot and then mercilessly rip it to shreds. Out of the ashes something decent sometimes emerges.

As always, please don't hesitate to pay me a visit in my office hours if I can help at any of the stages of your writing. 

Week 4: Verification & Confirmation

Next week, we’ll be switching gears from the “Context of Discovery” to the so-called “Context of Justification”. An apparently motley collection of questions come up here, which will largely occupy us through fall break: How do scientific theories receive support from hypotheses? How do we gauge the strength of this support? Can we offer any justification for treating evidence the way we do? How does all this bear on whether a theory counts as scientific in the first place?

On Tuesday, we’ll think again about the Hypothetico-Deductive account of confirmation that we encountered back in Week 2. Though Hempel’s description of it was rather plausible, it faces a number of problems. One problem we will be rather quick with: it involves using the idea of verification as a way of separating science from other fields (such as metaphysics). What’s metaphysics? French is brief because the question is tricky (true generalizations about metaphysics are scarce), but let me say a bit more than French does.

Despite what bookstores might have you believe, Metaphysics (in philosophy, anyway) does not concern fortune-telling, divination, or astrology. Rather, it concerns a cluster of topics about certain fundamental features of the world (including ourselves) that are not clearly susceptible to empirical treatment from the sciences. For example, many metaphysicians wonder whether we have free will. While results from physics or neuroscience may bear on this question, it is far from obvious that they’d be able to settle it. Conceptual work looks like it’d be necessary. Ditto for other paradigmatically metaphysical questions, such as when some objects compose other objects, how they persist, whether there are any “abstract objects” (such as numbers or qualities), what the nature of time or causation is, and so on (for more, you might check out the Stanford Encyclopedia of Philosophy (“SEP”) entry on Metaphysics). There’s currently a vigorous debate in philosophy about what the proper relationship is between metaphysics and science, but for a long time many philosophers (particularly, the Logical Positivists) got so sick of metaphysical pronouncements that they attempted to construct ways of showing not only what made science special but what made metaphysics worthless: there was no way of verifying metaphysics claims, they said. Perhaps such claims are even meaningless. They’re like “Green ideas sleep furiously”: while they might seem meaningful at first glance, they don’t really mean anything. How would one verify that green ideas do sleep furiously? (“Well, first you get some green ideas. . . .”)

There are a number of reasons why this tempting idea doesn’t work in general. As French explains, as the fortunes of the verification camp waned, an emphasis on confirmation took its place. This is roughly the context in which we find Hempel working: attempting to clarify how confirmation works. One of the interesting dynamics we’ll take an extended look at over the next few meetings is the tension between the feeling that something like his account is on the right track (at least descriptively!) but finding it devilishly difficult to get the details right.

On Thursday, we will discuss one of the most famously difficult problems in philosophy: the problem of induction and its relevance for scientific confirmation. It is in fact what drives Karl Popper to his fascinating views about science as a series of “conjectures and refutations” — a view we will discuss in more detail in weeks five and six. The problem is generated by asking a simple question: how is inductive inference to be justified? How can we show that the methods we use to infer from specific observations the very general facts (that all emeralds are green, that tigers are carnivorous, that material objects obey F=ma, &c.) that science is awash with are good or reliable methods? The inductive skeptic (spelled ‘sceptic’ in Foster’s article) denies that this is possible. She doesn’t deny that our inductive efforts have been successful. That is not at issue. That is obvious. The question is what, if any, reason such past success gives us for thinking that our inductive methods will continue to be successful. The skeptic offers us a compelling argument that there is nothing about our previous experience that should incline us even toward the probability that things will continue as they have. It turns out that the skeptic’s argument is very difficult to rebut. No one (in my view) has yet done so successfully. However, I’m not ready to give up on inductive inference. The stakes are too high: according to many, the rationality of science hangs in the balance!

Tuesday (9/13): Verification & Confirmation

French, pp. 43–49

Hempel, “Criteria of Confirmation and Acceptability”* [PDF]

Note: The Hempel paper here is optional supplementary reading — it’s really interesting, though, and I will discuss it in class, so I recommend you read it. But I won’t count on you having read it, though I think it’s worth reading. In the future, I will merely mark these sorts of “further reading” assignments with an asterisk.

Questions: (respond to two)

1. Does “verifying” a theory mean showing that the theory is definitely true? Why or why not?
2. Try to state the argument against using the verification principle as a demarcation criterion as clearly as you can (and in your own words, of course). 
3. French mentions “a more plausible” version of the verification stance on p.47: that the “greater then number and variety of verifications the greater the support for the theory and the higher the probability of its being true”. Can you think of ways in which this simple statement is pretty clearly too simple?
4. Explain in your own words the Quine-Duhem problem (as conveyed by French).

Thursday (9/15): The Problem of Induction

Foster, "The Problem of Induction" [PDF] — note: you can safely ignore for now the bit about Goodman on p. 5 (we’ll get to Goodman properly soon enough)

Popper, selections from The Logic of Scientific Discovery [PDF]*

You might wish to look over pp. 17–23 of French again before diving in to this week’s reading.

Questions: (respond to one)

1. Why can’t one validly deduce from the premises that unsupported coins have always fallen that this coin will fall if I release it? Explain as clearly as you can.
2. Why does it not help to rely on a principle about the uniformity of nature? Can you think of reasons other than those mentioned by Foster for being skeptical about such a principle?
3. Can the inductive skeptic be reasonably interpreted as urging us to be modest about drawing general conclusions from particular matters of fact?
4. Choose one of the three rebuttal strategies that Foster discusses in §IV: rephrase the debate in your own way, adding clarifications or raising questions you deem appropriate.

The Box Project Begins

I've asked Professor Hardcastle to give you the last 20 or so minutes of class on Tuesday to form yourself into groups for the Box Project. This is part of the project: scientists don't generally get put into groups by some authority; they work it out.

While I will insist that there be at least two groups, I place no other restrictions on their composition. This is up to you. Small groups will obviously be able to afford a nicer dinner if they win; they might also find it easier to find the time to meet. On the other hand, larger groups might have more resources available to them.

Please show up to our room as usual on Thursday. Jane Baker will sign you in and provide you with a handout to complete with your group. This will be due by Friday at noon. Please let me know if you have any questions. Have fun!

Week 3: Analogies & Heuristics

As I mentioned, class on Tuesday will be run by my “academic brother” [i.e., we had the same Ph.D. advisor], Professor Gary Hardcastle. I will be at a conference in Spain. (Don’t hate me, please.) At the end of class, Professor Hardcastle will give you approximately 20 minutes to sort yourselves into groups to work on the box project. You’ll spend Thursday working with your group to formulate an initial plan for the project. The academic assistant for Philosophy, Jane Baker will provide you with further instructions when you come in on Thursday. If you want to go off and meet elsewhere (like 7th St. or some such), that’s fine, but I would like everyone to show up, sign in, and actually use the time to meet — it shouldn’t take longer than the usual class time to do what I’ll ask you to do.

So far, we’ve seen two models of how science gets done: the overly mysterious and romantic view that puts genius and creativity on an unassailable pedestal and the meticulous inductivist view. And we’ve seen a few reasons for being worried about those models, at least in their simple formulations (we’ll actually encounter the inductivist view in a more sophisticated incarnation in Week 5). French presents the heuristics approach as a third model. But there are worries here too. First, we humans tend to be pretty easily seduced by fallacies (recall the fallacy of affirming the consequent that Hempel mentioned in his article from last week). Second (and relatedly), we suffer from all manner of cognitive biases. Nevertheless, we can identify all manner of cases of scientists apparently employing “heuristic” moves to press their research further. The chapter outlines and discusses some of these moves in the context of brief case studies. You might think as you read about why such heuristic moves were made in the first place and how they came to be.

Tuesday (9/6): Heuristics and Analogies
French, Ch. 4.

Questions: (respond to two)  Please CC Professor Hardcastle <ghardcas at bloomu.edu> on your responses.

1. Think about why concerns about fallacies and cognitive biases are arising in this context. Why should they not equally be a problem for the Romantic or inductivist models?
2. How seriously do you think we should take the sorts of concerns French raises in the first part of the chapter for his discussion of particular heuristic moves in the remainder?
3. Not surprisingly, French chooses cases where the heuristics (by and large) worked out. Can you think of cases where a particular heuristic move did not?
4. How do you think that the heuristics picture fares in comparison to the others we’ve looked at so far? 

Thursday (9/8): Project Work Day
No required reading. Please show up in our usual room with your group already formed. Jane will deliver instructions for how to begin the box project.