How does Paul Feyerabend, one of the most important philosophers of Science, tackle the question of scientific truth? What is the philosophy of science, and what is its purpose? We will explore Feyerabend’s approach to science by analyzing some important concepts: incommensurability (by way of a detour about another prominent philosopher of science, Thomas Kuhn), Feyerabend’s historical analysis of the relationship between science and observation, and his conception of the ideals science should aspire to.

The Philosophy of Science and Feyerabend

It is worth starting with a brief introduction to the philosophy of science and its purpose. Philosophy is an attempt to ask and answer some very basic questions, which has the potential to turn us away from questions of practical significance. The philosophy of science is a discipline that touches on many of these basic questions, but tries to put them to practical use.

The status of science is one of the main things in contention here—some people think that science has become the dominant mode of thinking in Western intellectual culture, or perhaps simply in Western culture more broadly, and that this is undeserved and leads us to make certain mistakes. Significantly, these debates about the status of science have come to have a distinct effect on the practice of certain sciences, especially in the human sciences.

One of the most controversial approaches to the philosophy of science comes from Paul Feyerabend. Feyerabend was an Austrian, who began his academic career as a scientist before moving over to the philosophy of science. Although he was for a time Karl Popper’s academic assistant, rather than taking Popper’s rather common-sense view (or at least self-identified common-sense view) of science, Feyerabend’s theory was and remains a radical intervention in the history of the philosophy of science.

Indeed, one of Feyerabend’s books (which is also undoubtedly his most famous) is simply called “Against Method.” His stance was known as epistemological anarchism, and as with many philosophies of science, Feyerabend’s theory suggests a certain conception of the ideal for science as a practice and for the scientist as a figure.

For Feyerabend, a great science is opportunistic, creative, and unbound by any particular rules or method in undertaking scientific activity. This sounds, to the nonscientist and to many scientists, extremely bizarre. So how did Feyerabend end up developing this way of thinking about science?

Some Intellectual Context

To understand Feyerabend’s ideas, we have to delve into the relevant intellectual context. In particular, we need to start with an idea that comes from another major philosopher of science, Thomas Kuhn, which Feyerabend adopted and developed in crucial ways. That idea is that of incommensurability in science.

Kuhn’s idea is that science does not change in a cumulative, steady, drip-drip of progress. Rather, science changes in sudden revolutions (which explains the title of Kuhn’s most famous book, The Structure of Scientific Revolutions).

Whenever you have a scientific revolution, something is lost and something is gained. Questions that had been answered by a previous paradigm either become puzzling again, or they cease to be questions at all. There is no unbiased mode of comparison between theories—one cannot simply stand outside of any particular scientific paradigm and make judgments about which one is better. Different paradigms are, therefore, incommensurable.

Of course, biased comparison is entirely possible, and in fact, Kuhn thinks it is utterly usual to stand inside one scientific paradigm and offer a critical view of other paradigms. But why is that?

First, unbiased comparison is impossible because of the communication failures which Kuhn sees between paradigms—they use different terms, use certain terms in different ways, and so on. Moreover, even when communication is possible, different paradigms will admit different standards of evidence.

All of this has much to do with one of the most pervasive ideas in modern-day philosophy of science, namely that of the holism of theories. This idea, due in large part to W.V.O Quine, holds that we cannot pick out one term of a theory and analyze it in isolation from the broader set of assumptions that are necessarily concomitant with it.

There is a historical issue that we can raise with Kuhn’s view of theoretical incommensurability. If scientific theories were actually incommensurable in this way, then surely we would expect the history of science to bear witness to this. In contrast to this, it seems that, in fact, genuine miscommunication is not a defining feature of the history of science—what Godfrey-Smith calls “scientific bilingualism” is very common, and certainly seems possible.

Scientific Revolution and Galileo 

After this extensive but necessary detour covering the idea of incommensurability in mind, let’s get back to Feyerabend. There are two kinds of arguments in Feyerabend which have had the most significant effect on philosophers of science. There is an argument about the history of science, and another argument about the relationship between science and human well-being. We will largely focus on the former.

The argument from history focuses on a famous example of scientific progress being made—that of Galileo and his arguments in support of the Copernican model of the solar system (chiefly, claiming against the prevailing Aristotelian view that the sun does not, in fact, go around the earth, but that the earth goes around the sun).

Galileo confronted various arguments against his view, but the ones which Feyerabend wishes to focus on are arguments from observation. Part of why Galileo’s theory was so controversial was that it appeared to fly in the face of all observations of heavenly bodies at the time—the sun appears to move, and we do not observe the earth on which we stand to be in motion.

Galileo offered explanations of these observations that could reconcile them with his theories, but he himself marveled just like Copernicus and his followers, for the “sheer force of intellect” with which he had “done such violence to their own senses as to prefer what reason told.”

Feyerabend’s view of what is going on here is simply that Galileo created a different kind of observational description of the world. The emphasis here should be on the term “created”—Galileo created a compatibility between observations and his theory. According to Feyerabend, science challenges observation rather than following it dutifully.

Feyerabend Against the Vienna Circle

This conception of science is intentionally at odds with that which Feyerabend takes to be a dominant conception of scientific activity in the philosophy of science, one which stretches back to the 17th century. This is a kind of simple empiricism, which takes the naïve conception of science as simply following observation and attempting to explain or generalize explanation. This is a conception of science that appeals to non-philosophers and often appears to be a feature of popular discourse around science, and which some modern philosophers, such as the members of the Vienna Circle, have adhered to.

Feyerabend’s point is not that this idea is wrong at some purely theoretical or philosophical level, but that if scientists adhered to it, then interesting, progressive science would never take place! Science often requires a massive rethinking of ordinary experience. This is Feyerabend’s extension of the Kuhnian concept of incommensurability.

In Feyerabend’s opinion, it is admirable to go against “reason” in the service of science, although perhaps something more like “common sense” is appropriate here. The point is that we should not use observation to construct strict rules about what science can and cannot say, which theories it can and cannot posit.

Feyerabend Against Popper 

Feyerabend does suggest some rules—rules which are, by his own account, made to be broken, but rules nonetheless—for science and for scientists.

First, there is the “principle of tenacity:” rather than seeing the abandonment of theories that have been shown not to work as a kind of scientific virtue (as, for instance, Karl Popper does), Feyerabend believes that scientists should work hard to hold onto theories and allow them to develop in light of criticism.

Second, there is the “principle of proliferation:” this tells us to make new theories, to propose new rules, and it works as a corrective to the potential for stasis were we to follow the principle of tenacity alone. Feyerabend is for a diversity of ideas. He isn’t quite as skeptical as Kuhn about the possibility of taking a constructive, yet external position with respect to a certain theory.

Part of the value of radicalism in science is that it might provide the kind of vantage point from which we can gain a new understanding of our existing theories. The greatest issue with Feyerabend is, in certain ways, a simple one. He appears to want to make science more like the humanities or art, but the social role—the practical purpose—of science belies this. Rigidity, in the sense that it refers to providing clear, relatively fixed answers to practical questions, is a necessary element of that social role, and Feyerabend’s failure to account for this in his theory is one of the most significant problems many subsequent philosophers of science have had with his point of view.