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“Falsifiability”

In critical rationalism, popper on 18/06/2011 at 12:31 am

Recently, a friend of mine sent me this criticism of falsifiability published in Edge.org in 2008 by Rebecca Goldstein, the wife of Steven Pinker and author of a few decent (so I hear) books. Upon reading it, I knew I had to write up a good ‘fisk’ of the criticism, seeing as it provides a good opportunity to clear up some misconceptions.

I. Some background

First, I detest the word ‘falsificationism’: it carries too much baggage. People, even people I hold in high esteem, see the word and immediately link it to the Logical Positivist theory of meaning, verificationism. The word is so loaded that it pigeonholes the entire enterprise from the beginning. This is why I think W.W. Bartley’s work on Comprehensively Critical Rationalism is an improvement on falsificationism, since it makes explicit the radical nature of the program: it extends Kant’s own critical philosophy to epistemology. We do away with support entirely.

The criterion of falsifiability, then, can be taken in at least three different ways (1) as a criticism of theories that claim to give empirical predictions, and yet are compatible with any state of affairs, or (2) as a criticism of actions taken to surreptitiously protect theories from testing through increasingly ad hoc adjustments, or (3) to demarcate empirical theories from non-empirical theories.

With that out of the way, let’s continue to Goldstein’s paper.

II. Where I get increasingly angry

But then I started to read Popper’s work carefully, to teach him in my philosophy of science classes, and to look to scientific practice to see whether his theory survives the test of falsifiability (at least as a description of how successful science gets done).

When I see this type of language, I grit my teeth and pray that I won’t have an aneurysm. Let’s begin with the criticism that criterion of falsifiability is not itself falsifiable. That’s one of the oldest (and most unfair) readings of Popper’s work. I remember when I first read Popper that I immediately thought of this same pseudo-objection: if the Logical Positivists’ criterion of meaning was itself meaningless by its own lights, then perhaps Popper’s criterion of science is not scientific!

… yes. That is true. It’s not scientific. No one claims that the criterion of falsifiability is scientific, for it makes no empirical predictions. Yet, even though the criterion is not a scientific statement, it’s a meaningful statement, which sets it apart from the Logical Positivists: it’s a criticism of theories that claim to make predictions while in fact they make nothing of the sort. Once that distinction is laid bare, then how is Goldstein’s objection of worth? I don’t care if falsifiability is falsifiable or not; I care if it is or is not a necessary and/or sufficient demarcation between scientific and non-scientific statements.

If Goldman wants to talk about ‘successful science’, I don’t know about you, but I immediately think of what inspired Popper in the first place: Einstein’s revolutionary theories and their highly conjectural (and highly testable) nature. Were Einstein’s theories ‘successful science’? Of course.

For one thing, Popper’s characterization of how science is practiced—as a cycle of conjecture and refutation—bears little relation to what goes on in the labs and journals.

In that case, either scientists are entrenched in Kuhn’s ‘normal science’, or … scientists are entrenched in ‘normal science.’ If Goldstein is correct, then something has been lost along the way, something important, involving the constant criticism of competing hypotheses. Of course, I don’t believe that for a minute. Criticism is rampant in science. Or, at least I hope it is.

But put that aside for the moment. Assume that Goldman is correct. Does the process of conjecture and refutation deal with the sociology of science? Only insofar as scientists behave critically towards their theories. The process of conjecture and refutation addresses the ‘logic’ of science: how science ought to progress if one wants better theories.

III. Here’s a break for you to rest your eyes

He describes science as if it was skeet-shooting, as if the only goal of science is to prove that one theory after another is false.

Let me go out on a limb here and say that Goldstein has not “read Popper’s work carefully,” seeing as this is a mystifying understanding of Critical Rationalism: the goals in science may be innumerable. For some scientists, they may seek fame and fortune; others may just want tenure.

I’ll put that aside, and I’ll give Goldman the best reading I can: she means only one of the goals of science. In that case, one goal in science is to “prove that one theory after another is false.” What does that mean? Proving that “one theory after another is false” means to eliminate error, and the only way I know to eliminate error is to work as hard as we can to show ourselves wrong. Does Goldman honestly think that the goal of science is only to search for corroborating evidence? I hope not. Does Goldman think that scientists ought not eliminate error?

Besides, the social mores of science push individual scientists towards being critical: you’ve got to be very critical of your ideas if you want to get them published. If you aren’t critical, there’s a scientist more than willing to criticize their failings for you and make you look like an ass. That’s called “prov[ing] that one theory after another is false.” Would Goldman have scientists refrain from being self-critical, or from criticizing the theories of other scientists? If so, then Goldman wants scientists to stop doing science. That would be absurd, of course, but how else am I to understand her objection?

Now, this is another issue that bothers me: there’s another very important goal to science, which is to produce interesting theories. It’s right there in the concept of ‘conjecture and refutation’: it’s the first part, the one that says ‘conjecture.’

To belabor the point, another goal in science might be to approximate interesting truths. Again, I know of no other way of getting closer to the truth than looking for our mistakes.

Scientists rarely write the way that Popper says they should, and a good Popperian should recognize that the Master may have over-simplified the logic of theory testing.

Long ago, Popper wrote a short article about journal reform, and how journal articles should be restructured so as to explain briefly the problem situation the scientists were in, provide details on their theory on how to solve the problem situation and how this theory could be tested, and the results of their experiments, positive or negative.

If scientists have not adopted these reforms, which, I should note, came from other people within the philosophy of science for some time, then I see only a problem for scientists.

And no, I don’t remember where the paper was published. I’m getting crotchety reading Goldstein, and don’t have the patience to wade through books right now.

IV. Here’s another break

Also, scientists don’t, and shouldn’t, jettison a theory as soon as a disconfirming datum comes in.

Ok. Now we get to the point where I usually start tugging at my hair.

If a theory (T) appears to contradict an experiment (~E), what can we know? Well, if you’ve passed intro to logic, you’d know that either (1) T is false, (2) ~E is false, or (3) T and ~E are false. It’s really, really, really, really basic. Really.

Wwhen we encounter ~E, there is no conclusive refutation of T, but it indicates that something’s rotten in the state of Denmark. Something could have gone wrong in the setup of the instruments, an auxiliary hypothesis could reconcile their differences, etc. This means that falsifications are never conclusive. Let me say that again: never conclusive.

Popper set out to incorporate specific methodological rules into science, one of them being the refusal to make ad hoc adjustments or excuses for a theory’s failure to agree with experiment. The scientist may spend their time examining the results of the experiment, and may in due time discover that the experiment was in error, but does that address Popper’s solution to the demarcation problem? Not in the least. The falsifiability of theories != falsifying theories in practice.

What stands out in the entire Critical Rationalist literature is that they stress this point repeatedly: all observation is theory-laden, and may be amended later through a critical discussion. In fact, they’ve been using this fact to undermine any sort of inductive inferences since the 30’s.

Goldstein’s misreading smacks of having read only Lakatos’ article on Popper as a naive falsificationist as published in Criticism and the Growth of Knowledge, and little more. Or, perhaps it comes from the term ‘falsification’ and all the misconceptions that stem from it. Or maybe it comes from Goldstein being an idiot. I’ll leave it up to you to decide.

Another problem with the falsifiability criterion is that I have seen it become a blunt instrument, unthinkingly applied.

Does this objection speak to the strengths or weaknesses of the falsifiability criterion? No. Then bring it up with the idiots that think the criterion is supposed to end debate, rather than provide a helping hand to scientists. Christ, this would be analogous to Goldstein objecting to ignoramuses that misuse the Occam’s Razor heuristic.

V. What?

Popper tried to use it to discredit not only Marxism and Freudianism as scientific theories but also Darwin’s theory of natural selection—a position that only a creationist could hold today.

Oh come on! This is just … just … flagrantly dishonest. Popper never attempted to ‘discredit’ evolution. He said it was one of the most valuable theory designed in the natural sciences: he thought at the time, and especially in the way it was formulated in some circles, that it provided a useful metaphysical research program on par with the early Greek atomism or Newton’s determinism, but it was not directly testable. Popper wrote extensively on the importance of metaphysical research programs in science, so her ignorance shines through like high-beams of idiocy. Why does Goldstein say something so pigheaded?

Before I forget, I should note that Goldstein is lying by omission: years later he learned that the theory of evolution was in principle testable, and publicly said that he was wrong, saying “I have in the past described the theory as ‘almost tautological’, and I have tried to explain how the theory of natural selection could be untestable … and yet of great scientific interest. … Nevertheless, I have changed my mind about the testability and the logical status of the theory of natural selection; and I am glad to have an opportunity to make a recantation.”

I have seen scientists claim that major theories in contemporary cosmology and physics are not “science” because they can’t think of a simple test that would falsify them.

Bring it up with the scientists, Goldstein.

But such is the godlike authority of Popper that his is the one theory that can never be falsified!

What? She can’t really? Huh?

Finally, I’ve come to think that identifying scientificality with falsifiability lets certain non-scientific theories off the hook, by saying that we should try to find good reasons to believe whether a theory is true or false only when that theory is called “science.”

OK. I’m done. I can’t keep this up. Is she serious?

It allows believers to protect their pet theories by saying that they can’t be, and shouldn’t be, subject to falsification, just because they’re clearly not scientific theories. Take the theory that there’s an omnipotent, omniscient, beneficent God. It may not be a scientific hypothesis, but it seems to me to be eminently falsifiable; in fact, it seems to have been amply falsified.

Fuck it. I’m getting a beer and watching Arrested Development.

//

  1. Who is this “Popper” that Goldstein keeps mentioning?

    I know of Karl Popper, but this other “Popper” sounds like an idiot.

    • I conjecture that Goldstein still would have trouble with this other “Popper”. So much for another critic of CR. Singer has an interesting one–my response to him should be up in a few days.

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