HPS 2501/Phil 2600     Philosophy of Science     Fall 2011

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Here's the question asked:

Kuhn listed values that play a role in theory choice (accuracy, simplicity, consistency, scope, fertility). Values, as opposed to facts, are freely chosen. Does this mean that our theory choices are arbitrary?

Having now read the essays submitted in response to this question, I realize that, in setting it, I failed to convey clearly what I had intended in the question. I really meant to ask this:

Kuhn's account of theory choice in science has been accused of denying that theory choice is objective. For it makes no provision for a factual grounding of theory choices. They are determined largely by social or psychological factors. Kuhn's response has been to give an account of theory choice in terms of values (accuracy, simplicity, consistency, scope, fertility). Does his answer enable him to escape the charge?

"I'm shocked, shocked to find that gambling is going on in here!"
Captain Renault (Claude Raines) in Casablanca

What I now realize is my own rather negative reaction to Kuhn's paper may not be shared by the seminar. That attitude informed the question. So here I want to explain why I think Kuhn's paper is deeply flawed.

In his celebrated paper (Thomas S. Kuhn "Objectivity, Value Judgment, and Theory Choice," Ch. 13, pp. 320-339 in The Essential Tension. Chicago: University of Chicago Press, 1977.), Kuhn reports that he is shocked, shocked to discover that his critics think of him as some sort of epistemic skeptic about theory choice. He reports their views with dismay. His first quote is of a colorful and extreme renderring of the criticism. It is Lakatos' accusation that Kuhn portrays theory choice as "a matter of mob psychology." Others reported are less colorful.

I cannot read Kuhn's report of dismay without in turn being dismayed myself over Kuhn's surprise. His celebrated Structure is famous for depicting successive paradigms as incommensurable, that is, impossible to compare rationally from within either paradigm. The adoption of a new paradigm by a scientist is akin to religious conversion. The work proceeds in this vein, recounting the role of herd psychology in science. Since such factors are surely at play in science to some extent, recounting them need not lead to a skeptical view. But to avoid the skeptical view, they need to be supplemented by some treatment of the role of factually grounded evidence in science and why, despite the issues Kuhn raises, our choices of theories in science are, in some significant measure, guided by it.

It is the omission of any discussion in the latter vein that has secured Kuhn his reputation as a skeptic. It is as if one were to write a lengthy treatise outlining all the dangers of airline travel, while carefully avoiding all mention that airline travel has an extraordinarily good safety record. One would justifiably develop the reputation of someone who believes that flying is risky. But you may never have actually said it.

This style of indirect writing enables Kuhn to convey strongly skeptical ideas to his readers without asserting them plainly. His "values" paper is his opportunity to set the record straight. But how does he handle it? He starts out by denying that he is advocating a skeptical thesis. He then proceeds to write a paper that uses precisely the same indirect methods to convey the same skeptical message. What astonishes me is that he gets away with it. Far too many readers of Kuhn's paper have their thinking fogged by his narrative.

How does the fogging work? I can identify three elements that combine to produce a paper that has proven near unmatched in its power to deceive.

1. "Values"

As with all good deceptions, the principal means is so overtly visible that it can be overlooked. Kuhn introduces certain characteristics of a good scientific theory: accuracy, consistency, broad scope, simplicity and fruitfulness. They are initially called "characteristics." However some ten pages into the paper they are relabeled as "values."

This relabeling is far from benign. It has long been traditional in philosophy to distinguish "is" from "ought." The "is'es" are factual. The "oughts" are not. They have very different statuses--or at least it has traditionally been so. I haven't been keeping up with the latest in ethical theory. Following this traditional is/ought distinction, values are not the sort of thing that is given factually by the world. They are chosen, typically by a culture. The choices can vary. Some cultures absolutely prohibit killing humans. Others authorize it in wartime or as retribution in a judicial setting. In some religions, human sacrifice is routinely sanctioned to appease the gods. In others it is unequivocally prohibited. Still others sanction just a small, finite number (e.g. one).

Values, in this familiar tradition, cannot be factually grounded. So whatever choices are made under such values are correspondingly not factually grounded. The Pennsylvania Dutch do not permit the killing of humans, even of our enemies in wartime. Those with different values may debate with them, comparing the values in myriad ways. In the end, however, the Pennsylvania Dutch can simply insist that it is their value not to kill even in wartime. They make no factual mistake.

When Kuhn says that our theory choices are governed by "values," he conveys to those who recall the is/ought distinction that the choice is not factually grounded. The message is passed effectively to the reader, but in standard Kuhn style, he has not actually said it.

Of course there is a lot more that Kuhn says about the values. This is more of the fog that obscures what would otherwise be so obvious. The values chosen by scientists do indeed form a relatively stable set. They can be vague and hard to apply. Tradeoffs are needed. One soon gets distracted and lost and the big deception is overlooked.

2. Redefining terms

The charge against Kuhn is that that theory choice, in his account, is not objective. Here "objective" means factually grounded. Another way to level this charge is to say that Kuhn portrays theory choice as irrational. Here the sense of irrationality is narrow. The goal of science is to get at the truth and that is done by factually grounded investigations. Theory choice is in this narrow sense is irrational in so far as it fails to advance us towards true theories. Choosing theories by means other than those that are factually grounded does not advance us to this goal.

The difficulty is that terms like "subjective" and "objective" can carry many meanings. Kuhn exploits this ambiguity. He asserts that his account is not subjective, as long as subjective is not opposed to objective, but to judgmental. For, he says, the selection of the values is quite discussable, whereas matters of taste are not. So Kuhn secures the rationality of the choice of values by urging that scientist have reasons and argue about them. That is a sense of rationality. But it is not the sense at issue. The choices that concern us are rational in so far as they support the goal of getting at the truth.

What of objectivity? Kuhn urges that "objectivity ought to be analyzable in terms of criteria like accuracy and consistency." That is, it is to be explicated by the values; and if we understand that values are not factually grounded, then objectivity is divorced from factual grounding. The misdirection of terminology is complete.

3. What is not said

As with structure, what is most important is what is missing. Why is it appropriate for scientists to use the criteria that Kuhn calls values? They are appropriate in that the best of them are readily shown to be truth conducive. Choosing theories under their guidance leads us to our goal of true theories. It is easy for a sympathetic reader to augment Kuhn's account silently by such considerations and thus to conclude that Kuhn's discussion is benign.

Once one wants to start, the connections are easy to make. Take consistency. We do not think that an inconsistent theory can be true. For it will assert that some factual proposition A is true and that it is not true. States of affairs in the world do not permit that. So, if we have an inconsistent theory, we know we have work to do. We may just discard the theory. Or we may decide that there is a consistent theory in the vicinity and that repairs to our inconsistent theory may bring it to us. Take accuracy. A long-standing tradition in inductive inference portrays it as a mark of truth when some theory entails true observations. Accuracy implements that idea. The other values are more troublesome. Most troublesome is simplicity since the world is not simple. It is only simple in a highly contrived formulation; and it is not at all straightforward to understand why the search for simple theories gets us closer to the truth, or even if it does.

These connections between values and the goal of getting to true theories can be made. If Kuhn wanted to make these connections, it would be easy for him to do it. They key point is that Kuhn himself never makes these connections. Indeed he goes to some lengths to avoid making them. His goal is a narrative that makes no mention of the factual grounding of theory choice and how this advances us towards the truth. Then he is shocked, shocked when his critics point this out.

The crazy cult comparison

There is a simple way to see how Kuhn's account is a skeptical account; or at least that it fails to discern what enables science to succeed at finding out about the world. Pick your favorite crazy cult whose doctrines are fantasies. Pick one that has a fairly elaborate body of doctrine and a healthy, if contained, literature concerning it. Everything Kuhn says in his values paper can be applied to this cult. They will have a body of values governing their choices in refining of doctrines. The body of values will be stable, but, no doubt have all the familiar problems: vagueness of application, tensions among them, and so on. Most importantly, they will not be subjective in the Kuhnian sense, in that their adoption and use will be governed by reasons and arguments. Doctrinal disputes in cults are notorious for their fervour and longevity. That is rationality on Kuhn's account.

The cult's values will be different form those of the scientists. The cult will likley not value consistency and empirical accuracy. Logical inconsistency is often celebrated as a deep mystery to be revered. But that difference does not matter to Kuhn's account. Nothing in Kuhn's account depends on the particular content of these scientific values.

My summary verdict as an argument.

From an epistemic perspective, what is important about science is how it differs from other human activities. For science has enjoyed vastly more success in finding out how the world is than any other human endeavor.

Kuhn's account of science is fully devoted to describing how scientific activity is like other human activities. The account works for cults as well.

Hence Kuhn's account is powerless to discern the thing that matters most, epistemically, about science.