Kuhn Challenges Philosophy of Science

Is Kuhn leading science towards mob psychology? Despite his deflationary treatment of science, it is not his treatment of normal science that got people upset, it is his treatment of revolutionary science that produced so much controversy. Many thinkers found it deflating of science’s aspirations and pretensions (depending on which side you lean on). To Kuhn, when an old paradigm can no longer restore order or produce a successful solution to a problem after a prolonged crisis, a new paradigm emerges to govern the field. A single paradigm must take hold and generate consensus for normal science to get done. A new paradigm distinguishes itself by showing a strikingly new problem-solving power. It hardly sounds undermining scientific rationality. Think again: do the notions of rationality and truth play little role in Kuhn’s explanation of the rise of a new paradigm?

A new paradigm will have achieved some impressive successes, but in general, it will be relatively undeveloped, and it will not be able to solve all the puzzles that the old paradigm could solve.

“A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.”- Max Plank 

But Kuhn rejected the triumphalist picture of old fuddy-duddies with their superstitions being superseded by clear-thinking young minds who now see the plain truth. Generational differences and other non-evidential factors come to the fore during a scientific revolution precisely because the evidence is inadequate to settle the matter. There is no possible standard by which the promise of the new paradigm can be compared with the achievement of the old. Young scientists are willing to jump to the new paradigm not because they are less biased, but because it is easier for them to do so, because they are not invested enough in the old paradigm. In normal science, there is little room for the personal and the idiosyncratic. In the freer conditions of crisis science, however, many personal factors can affect paradigm choice: a theory may look elegant and simple, but that is an aesthetic judgement; or on the basis of metaphysical beliefs- Einstein objected to Quantum mechanics. 

Much of Kuhn's position can be summed up by his insistence that rival paradigms cannot be judged on a common scale. In Kuhn’s term, they are ‘incommensurable’. This means they cannot be compared via a neutral or objectively correct measure. Now, this is an immensely controversial thesis. How does Kuhn defend it?

Defense 1: Standards of evaluation vary too much across paradigms to be of decisive use.

Certain values are permanent parts of science: predictive accuracy, consistency, broad scope, simplicity, and fruitfulness etc. If we leave these values vaguely described, everybody will agree that scientists do and should take them into account. However, if you insist on strictly defining these values, rational disagreement- such as what constitutes simplicity, is in play. And any precise definition of simplicity is going to be controversial, though the value of simplicity will not be controversial. More deeply, the comparative weight assigned to each value can vary without anybody having departed from the standards of doing science. But these values can be interpreted, weighed, and applied in different ways. They often conflict with one another. Thus, work in each paradigm is governed by scientific values, but each paradigm will hold work to the standards provided by that paradigm. Even within a paradigm, these values do not function as explicit principles but, rather, as shared habits and ways of seeing things. This is crucial for the proper functioning of science, but it limits the role of explicit, reasoned comparison of paradigms.

Defense 2: Effective communication across paradigms is very difficult.

Like W. V. Quine, Kuhn adopts a holistic conception of meaning. Both are influenced by the positivists' idea that terms and statements get their meaning from their role in deriving observational consequences. For example, mass. In a holistic view of meaning, mass is not a fixed definition; rather, it is connected to how it functions within the entire scientific framework or theory. It is never about understanding the word mass in isolation; it’s about understanding how it fits into the broader theory in physics, how it interacts with other concepts like gravity and motion, and how it helps us make predictions or explanations about the behavior of objects in the universe. 

The word ‘mass’ gets its meaning from its role in deriving observational consequences. Its meaning is a matter of every connection with other statements in the scientific theory the term bears. Now, since the meaning of a term or statement derives from this role it plays in the web of belief, changes elsewhere in the web can bring about significant changes in the meaning of a scientific term or statement. An example-

Carless thinking would lead us to think that Einstein’s conception of mass is an extension over Newton’s conception of mass. Newton’s objects do not move at a significant fraction of the speed of light, while Einstein covers all the Newtonian cases, and then extends the theory to objects moving at an approximation of the speed of light relative to our reference frame. This fits the standard view of science, that one paradigm improves on the other, and science progresses forward. After all, all of the observations that favored Newton also favor Einstein. Einstein corrects a few of the mistakes and limitations of his predecessor, and science gets better. Wrong. 

In Kuhn’s view, the word mass means something different in the two theories. It is not as straightforwardly comparable, or commensurable as the standard view has it. Why? Because Einstein’s mass is convertible into energy, Newton’s is not. A Newtonian wouldn’t see this change of the meaning of ‘mass’ as an improvement or an extension; rather, a Newtonian would see this as a theory of different stuff with the same name. For this reason, Kuhn denies that a term such as mass means the same thing in Einstein's theory that it does in Newton's. Einstein offers a theory about different stuff, rather than an improved theory of the same stuff. Kuhn, therefore, contends that wholesale changes in the network of concepts occur when we switch paradigms, making the cumulation through clear communication across paradigms difficult.

For reasons such as these, proponents of different paradigms tend to talk past each other. Paradigm-neutral observations cannot be used to adjudicate between paradigms. 

Now we come to the crux. Perhaps observation can settle the difference and its evaluation within paradigms. During a crisis, there may not be enough data available. Let the data accumulate, and we will be able to see which paradigm provides the right way to go. Kuhn’s denial to this claim, perhaps more than any other, drives the critics crazy.

Paradigm neutral observations, Kuhn says, cannot be used to settle scientific disputes. Why? Because observation is theory-laden. What people see depends, in pertinent part, on what they already believe or expect. Perception is much less passive, less receptive than many had thought. Kuhn thus denies that we have access to a realm of observational evidence that is largely independent of theory and could, then, count as a source of meaning and evidence. Kuhn defends it by providing some empirical results: he draws on Gestalt psychology and tries to undermine the distinction between seeing and seeing as. He is now denying a claim which is sacred to the logical empiricists- that we can have access to observational evidence that is sufficiently independent of theory that it can be used as a source of meaning and evidence for a theory. 

Kuhn, then, commits himself to rather extreme-sounding versions of this point. He says that, in an important sense, followers of different paradigms inhabit different worlds. 

Science, then, cannot be seen as straightforwardly cumulative, progressive, or truth-tracking. Despite this denial of this objective sense accumulation, Kuhn does often write that science manifests a genuine, not just an apparent, kind of progress: the progress in problem solving. Science, then, is an incredibly successful activity. Kuhn runs his ‘it’s not a bug, it’s a feature’ argument. If science were more rule governed, less dependent on non-rational factors (social and political), agreement across crisis science would be reached too quickly. Everybody would be following the same notion of evidence. 

Science, then, has stumbled onto a mechanism by which crisis science as well as normal science has a distinctive job to do, analogous to the invisible hand. Normal science is quite dogmatic, and revolutionary science allows idiosyncrasies, neither of which is intellectually virtuous. But they function together in a complicated social arrangement that produces desirable outcomes. Thus Kuhn establishes his confidence in science as a social institution. 

But Kuhn’s argument, ironically, doesn’t solve the crux of the problem, that new paradigms do not solve more or better problems, only new problems. We could take steps to resolve this issue, but there is no guideline to read Kuhn for this settlement. Combines:

Any scientific revolution contains losses as well as gains. 

Science gradually increases problem solving power. 

We would be comfortable knowing science gains more than it loses after a crisis, but Kuhn makes no such claims. 

Kuhn does not accept any stories in which science progresses so as to get closer to the truth. For Kuhn, truth makes sense within a paradigm, but it’s an unclear and dangerous notion when applied across paradigms. 

Kuhn does not offer a theory of scientific method or rationale, no conception of inductive logic; rather, it’s a theory of scientific change. It is more descriptive than it is normative. This descriptive project deflates certain normative claims about logic and methodology. To what extent can it endure with its deflating and valorizing aspects?