in thread: whatever2001_05_09:00:22
The Falsifiability CriterionI responded today to some
discourse on the Psychology list
regarding the falsifiability criterion for judging theories. I think it might be common amongst objectivists to worry about this criterion. The worry goes, "I have good evidence that this theory is true--lots of it. So it can't be false. It's silly to say that my theory is only a good one if it could be false. So of course it doesn't fulfill that criterion; in fact, the criterion is suspect." I don't know how widespread this interpretation of the falsifiability criterion is. Since it is relevant to my work on propositions, I plunged in. One thing I didn't say in my post to the list but thought of afterwards, is that the aversion to this criterion might be due to a common bad practice in the use of thought experiments. I talk about this bad practice in my
dissertation. The problem is that some people try to use fantasy thought experiments to discount empirically-supported theories: if one can conceive, without self-contradiction, disconfirming evidence, then the theory might be false. This same language, I gather, is now being used to show that a theory is good because it is falsifiable: if I can't conceive of disconfirming evidence, then the theory holds up under the falsifiability criterion. It's very twisted language and hard for laypeople to follow, and hard for objectivists to swallow, so I worked through the tangles like this:
My understanding of the falsifiability criterion is this. Consider some theory you've just proposed. Could I say _anything_ that would make you question the theory, in principle? People who subscribe to a genuinely unfalsifiable idea will always answer "no". People who subscribe to a genuinely falsifiable idea will always say "yes." That doesn't mean that they think their theory is _false_; if they did, it wouldn't be their theory.
The most widely-used example of such an idea is God's infinite benevolence and love for humanity. The good job with a fat salary that you just acquired is attributable to omnibenevolence (OB) in the this theist's view. But what about the job you lost 4 months prior and the financial hardship that ensued? Oh, well, that was God's setup to get you this greater job. OK, how about the fact that my child was born with spina bifida just after the layoff? You see, that was your incentive to strive as hard as you did to get x, y, and z benefits. What about the millions of children who die slow, agonizing deaths from disease and starvation? They provide a good contrast object for you--if there weren't pain and suffering, you wouldn't know how happy you are. But what about them? How does OB benefit _them_? I'm tempted to say that I'm the protege of a Really Benevolent God, while they are the victims of a Pretty Powerful Sadist. Oh, no, you see, there are things that God does that we don't understand. This is one of them. God _is_ OB; you just don't understand all that that entails.
So, I don't see it as a question of being able to _imagine_ evidence that would falsify the theory; in the above examples, we actually _have_ those facts at hand. Falsifiability comes into play when the defender of the theory would be unwilling to give up the theory no matter _what_ evidence, real or imagined, is suggested, and is willing to change even the meanings of the terms in order to make the evidence fit the theory. In other words, the theory fluidly changes whenever disconfirming evidence is suggested, all the while continuing to call itself the same theory. Marxism is similarly accused of being unfalsifiable. One red warning flag is the claim that a theory explains
_everything_, including two contradictory pieces of evidence, which OB
does. The warning flag is reason to take a closer look at the theorist's
methods and claims.
Evolutionary theory is falsifiable in this sense: Suppose we got evidence that those "bones" that we have in museums were just very interesting objects d'art, and we've all the while thought that they were from real animals? If evolutionary theory is falsifiable, then we'd have to say, yes, that would count as evidence that the theory wasn't true; and if we got enough evidence like that, we'd say the theory wasn't true. If someone's "evolutionary" theory is unfalsifiable, then he would say, "No, that evidence MUST be mistaken, because my theory is correct; I don't care how much of it you get, I won't admit it as disconfirming the theory." This is what it means to say that disconfirming evidence cannot be conceived. Conceived by whom, is the question.
Like any proposition, a theory exists only in virtue of the mind that proposes it. In part, we have to judge the way the theory is held, not just the plain linguistic statement of it. I personally proposed that evolutionary theory is true and falsifiable: if you can give me evidence that aliens visited the planet and left the bones of their deceased pets here, then I'll happily rethink my theory of evolution. Or if you can show that they are really ancient pottery shards, or that they aren't really that that old. Any of these new facts, were they facts, I would take as disconfirming.
But if I believe that God's love is simply beyond my understanding, I don't care what kind of evidence, real or imagined, you present; if I can't tell you how it fits the picture of an OB God, then I will say, "I don't know how this demonstrates OB, but it does, and if you were omniscient like God you'd see how." A person with a falsifiable theory does not say this. Note that this is different from what Tom Radcliffe said in his last post: Our theist is not saying, "I don't know why my theory of OB doesn't account for that data;" he's saying, "My theory DOES account for that, I just don't know how; or else it isn't real data."
In conclusion, I don't think theories can be judged without reference to the minds that hold them. I can't just say "The theory of evolution is that human beings evolved from apes." I also have to say, "And I WOULD consider disconfirming evidence," or "I WOULD NOT consider disconfirming evidence."