We live in a world where claims about everything from climate change to health remedies are constantly vying for our attention. How do we figure out which claims are grounded in solid science and which belong to the realm of pseudoscience? This isn’t just an academic puzzle; it has real-world consequences for our health, our policies, and our understanding of the universe. Philosophy of science has long grappled with the problem of demarcation – finding a principled way to distinguish genuine sciences from those that merely claim that special status.
While you might intuitively think science is about proving theories right, finding lots of evidence that confirms them, the influential 20th-century philosopher Karl Popper offered a radically different perspective. Born in Vienna, a hub of intellectual activity, Popper observed theories like Karl Marx’s theory of history and the psychological theories of Sigmund Freud and Alfred Adler. At the time, these were widely considered genuinely scientific.
Popper, however, became disenchanted with such theories. He was particularly struck by the contrast between them and Albert Einstein’s theory of relativity. What set Einstein’s work apart, for Popper, was its openness to criticism. This led him to propose a new criterion for distinguishing science: falsifiability.
Popper argued that finding confirming evidence for a theory is often “cheap.” Pseudosciences, he claimed, can find supporting evidence everywhere. Drawing on the psychological theories of Freud and Adler as examples, Popper noted how their proponents could find confirming evidence in “many case studies.” Even more tellingly, apparent counterevidence could be easily dismissed or even turned into confirming evidence by a clever proponent. Freud and Adler, he argued, “had ready explanations for any observational result.” According to Popper, this meant that no evidence falsifies a pseudoscientific claim, and almost everything confirms it. This led him to see the seemingly standard virtues of scientific theories – explanatory power and confirmation by many instances – as being closer to vices in the context of pseudoscience.
For Popper, genuine science doesn’t seek endless confirmation; it seeks to design severe tests aimed at proving its hypotheses wrong. A scientific theory, he argued, must be falsifiable – it must be possible, in principle, for observations to show it to be false. If a theory withstands these attempts at falsification, it is considered corroborated, but Popper was careful to note this doesn’t mean it’s proven true, only that it hasn’t been shown false yet.
However, Popper’s elegant solution has faced significant criticisms, and the search for a clear demarcation criterion continues. The line between falsifiable and unfalsifiable statements can be “tricky.” For instance, statements involving probabilities are difficult to falsify conclusively. Furthermore, a theory often relies on auxiliary hypotheses to make predictions, and if a prediction fails, logic only tells you something is wrong in the whole system, not necessarily the main theory being tested. Scientists also don’t always reject theories simply because they conflict with initial observations; much scientific work involves resolving these discrepancies.
Beyond Popper’s criterion, other characteristics have been suggested as potential markers of pseudoscience in the sources:
- Lack of progress—One criterion is that pseudosciences tend not to make much progress, especially when compared to rival theories. However, defining and measuring “progress” in a way that applies universally is difficult. Astrology, for example, has changed over centuries, arguably in ways that could be seen as improvements.
- Absence of mechanism—Pseudosciences like astrology often lack a clear mechanism to explain how proposed effects occur. Yet, historical examples like Isaac Newton’s theory of gravity also lacked a physical mechanism initially. Social Practices: Some suggest a practice is scientific if the “right people” (e.g., university researchers publishing in journals) call it science and do “the right sort of scientific things.” But this risks counting institutionalized pseudosciences, such as Lysenkoist biology, as scientific.
- Dubious origins—Pseudosciences can have epistemically dubious origins. However, this doesn’t distinguish them from genuine sciences like chemistry (which originated in alchemy) or science more broadly (which arose from mythology and speculation).
- Forms of reasoning—It seems that pseudosciences don’t necessarily use distinct forms of reasoning. They might employ mathematical reasoning and make causal or explanatory inferences. Conversely, genuine sciences might sometimes use reasoning strategies like arguments from analogy that also appear in pseudosciences.
- Refusal to treat evidence as falsifying—A common complaint against certain claims, such as Young-Earth Creationism, is that proponents refuse to treat any evidence as falsifying their theory. This echoes Popper’s point, but it raises the question of whether this is a criticism of the theory itself or of how its advocates behave.
- Focus on “big questions” over testable ones: Some claims, like Intelligent Design Creationism, are criticized for being dominated by large, overarching questions without much “going on in the way of little questions that can be answered in labs.”
The consensus among most philosophers, as discussed in the sources, is that the demarcation problem has not received an adequate solution. There isn’t a solid basis for distinguishing between merely poor scientific theories and non-scientific theories. If a clear criterion remains elusive, it becomes challenging to definitively label something like creationism or astrology as “unscientific.” This leads to the provocative thought that perhaps decisions about what theories receive funding or are taught in schools should be based on whether they are good theories, rather than solely on whether they meet a potentially elusive standard of being “scientific.”
In conclusion, while Karl Popper’s focus on falsifiability provided a powerful and influential starting point for understanding what makes science special, it’s clear that the distinction between science and pseudoscience is complex and difficult to capture with a single criterion. Pseudosciences are often characterized by a resistance to being proven wrong, a tendency to find support everywhere, a potential lack of progress or clear mechanisms, and sometimes questionable origins or reasoning patterns. However, applying these criteria consistently and without encountering counterexamples from accepted science remains a philosophical challenge. Ultimately, understanding the characteristics of pseudoscience requires considering a range of factors, recognizing the difficulty of drawing sharp boundaries, and continuously engaging in critical thinking about the claims we encounter.