Some Thoughts on the Distinction between Legitimate Science and Pseudoscience

 In Building Knowledge, Words and Meanings

Some disciplines and systems of methods that have a wide number of followers and practitioners might seem to be scientific, but they are actually pseudoscientific.  This includes any belief systems that in some way take into account empirical evidence and that have rules for using this to purportedly better understand the world, but that are based on theories that are not epistemically justified.  The fact that these systems do involve empirical observation and rules for interpreting the findings from this and making predictions often tricks people into thinking that one can gain useful and reliable knowledge from these systems.

Twentieth Century philosopher of science Karl Popper identified pseudoscience as any system that involves theories that are not falsifiable.  A theory is falsifiable if it is conceivable that empirical data could be found that could show that this theory is false.  Theories that are not falsifiable are formulated in a way so as to interpret any possible data as a corroboration of the theory.  Popper identified Freudian psychoanalysis as an example of a theory that is not falsifiable because within this theory, any possible behavior of someone can be interpreted as being in line with its assumptions and there is no possible observable data that could allow a practitioner to challenge these basic assumptions.

Popper also identified astrology as pseudoscience because he figured that one can interpret star charts and personal behavioral data in any way that they want in order to match the experimental evidence.  Actually, in this analysis, Popper is not exactly correct.  For one thing, astrology actually does make vague predictions about the movement of the planets.  For another, many predictions made by astrology regarding personal behavior can be completely falsified.  What makes astrology pseudoscientific is that it takes into account some empirical evidence, but it interprets this data and tries to make predictions based on this data using rules that are quite unreasonable.

Any set of rules that an episteme uses to make predictions are supposed to somehow be based on natural laws or have some sort of indirect connection to nature.  If the rules that practitioners use to drive their investigations are entirely disconnected from nature then there probably isn’t anything about the natural universe that will be understood through these investigations.  These methods and procedures need to be understood as somehow controlling or bracketing certain aspects of the natural processes under investigation, otherwise the practitioners are only using their own fantasies and imaginations to interpret the world.   The rules and methods employed probably need to be based on theories with regards to the laws of nature and should be formulated and refined through empirical observation.

As far as astrology goes, it is based on a fixed set of rules that never get updated on the basis of new observations.  The most significant explanations and predictions supposedly made by astrology pertain to human personalities and behaviors.  There simply is no evidence that human personality is linked to the movement of the planets, as the theories of astrology claim.  These ideas could only have originated in someone’s imagination some 2500 years ago and were then made into inflexible dogma.  Astrology had maintained popularity for centuries leading up to the Age of Enlightenment because science had not yet developed a better understanding of the movement of the heavenly bodies nor of the inner workings of the human mind that drive our behavior.  Even though astrology is still popular in some circles to this day, we can now say with confidence that this discipline has been quite thoroughly falsified.  Its enduring popularity among many people in our highly science-based contemporary world might be partially due to the fact that, as a pseudoscience, it has the ability to trick some people into believing in its validity.

It is not difficult to create a theory from one’s imagination, and it is also apparently not that difficult to formulate a theory from imagination that interprets empirical data and provides unjustified explanations for how things work.  It is orders of magnitude more difficult to come up with a theory that is justified in being a model of a small slice of reality, which a scientific theory should be.  Though it is easier to practice pseudoscience than real science and some people have a tendency to believe unjustified theories if they seem scientific, over time only systems that use a genuine scientific method will be able to make reliable predictions and thus they will be more credible to people and pseudoscience will become less so.  As Carl Sagan has said, “Science is a self-correcting process.  To be accepted, new ideas must survive the most rigorous standards of evidence and scrutiny.”

The following is a generally accepted list of criteria that is the answer to the “demarcation problem”, which is the line between legitimate science and pseudoscience:

  • Reproducible: Makes predictions that can be tested by any observer, with trials extending indefinitely into the future.
  • Testable: Empirical tests can be conducted and result can be gathered that might or might not be in line with the theory.
  • Falsifiable: One can at least conceive of some empirical data eventually coming to light that would falsify the theory.
  • Consistent: Generates no obvious logical contradictions and is consistent with observations and the data that was directly gathered.
  • Pertinent: Describes and explains the observed phenomena.
  • Correctable and dynamic: Is subject to modification as new observations are made.
  • Integrative, statistically stable, and corrigible: Subsumes previous theories as approximations, and allows possible subsumption by future theories.
  • Parsimonious: Economical in the number of assumptions and hypothetical entities.  Provisional or tentative. Does not assert the absolute certainty of the theory.

f a science is driven by evidence and reason and its methods are refined over time through critical thinking, then we can say it is legitimate, since we would be legitimately using the word “science” to refer to it.  However, if a so-called science involves rigid rule-based analysis that is based upon an unchallengable dogmatic edifice, then it is pseudo, since this fundamental dogmatism would mean that this would not be a legitimate science.

Pseudosciences are presented in a way that might seem scientific to many people unless they have developed the skill to differentiate that which is legitimate from that which is pseudo.  Any episteme that is empirical and is driven by some sort of rules for what to observe and for what explanations and conclusions might follow from these observations is going to seem like a good source of knowledge to some people, simply because the presentation would seem to connect observations to explanations and conclusions and because the practitioners would seem to know what they are doing.  This dynamic often tricks people into thinking that pseudoscientific practices are reliable sources of knowledge, even though a closer examination would show that they are not.

Ultimately, this distinction hinges upon whether a methodology has a feedback loop built into it such that the paradigms and theories are adaptable based on the results of observations.  If it meets this condition, then it is legitimate.  Otherwise, it is pseudo.  In the end, there has to be accountability and peer review for any findings and conclusions that are generated through any legitimate science.

Both falsification and verification are important to any legitimate science.  Falsification is where observed results are entirely inconsistent with what a hypothesis would predict, reliably so, and verification is where observed results consistently corroborate a hypothesis such that it can rationally be considered to be grounded in some fundamental reality.  Only when there is strong and consistent connection between observed results and the interplay between these two such that the theories and frameworks can adjust accordingly, can a science be considered legitimate.

Legitimate sciences, generally speaking, go through paradigm shifts and revolutions occasionally in the face of new evidence that can’t easily be made to conform to the old paradigms.  The need to parsimoniously interpret data can lead to adjustments of the foundational assumptions and methods of the paradigm, especially over years and decades of normal science.  Eventually, this leads to a reassessment of the paradigm.  If the science doesn’t adapt in some form in order to best accommodate anomalous data and in order to optimally conform to the results, it would end up having to take on the character of pseudoscience in order to continue to be practiced in some form.

Recent Posts
Showing 2 comments
  • Matt Segall

    Thanks for these thoughts, Brandon. But I think we need to go far beyond Popper’s philosophy of science if we hope to account for the contemporary practice of science, including the hardest of the sciences (physics). Falsifiability cannot be the be all and end all of demarcation, because as Kuhn showed, reigning paradigms tend to ignore the falsifying data that does not fit into its framework. Indeed, because theory predetermines what is to count as salient data, often reigning paradigms do not even know what they are missing. That is, until the anomalies become too numerous to deny and a revolution occurs.

    As for astrology, I do not consider it a science, but more of an interpretative art. It has empirical elements, of course. But while I’d argue against those astrologers who claim it is “scientific” in any modern sense of the term, I nonetheless think it is a highly pragmatic lens through which to interpret history and biography in retrospect (I’m less convinced of its prognostic applications, though apparently Wall St. traders swear by it). I’d say something similar about psychoanalysis. More on my take on astrology: https://youtu.be/rz8aQHIwW_8

  • Brandon Norgaard

    Thanks Matt. Yeah I agree and I think there could be complex adaptive methods for us to consider some hypotheses and theories semi-falsified and semi-verified. Popper thought there could never be verification, but I think there sort of can be using a combination of Bayesian theorems and explanationism (Mill’s methods, etc.). Ultimately, I think the engine of science rests, in part, on this interrelation between falsification and verification, although neither of these occur in pure form. Both of these can occur in varying degrees, which is why I used the “semi-” prefix above. I guess I’m searching for other qualifiers, such as “virtual”, “highly likely”, “highly unlikely”. I acknowledge there could never be an overarching algorithm to encompass all of this, but at least I think we can create new paradigms for integrative yellow/teal level science. One effort that feeds into this is identifying the foundational epistemic dimensions, of which I think legitimate vs. pseudo science is one.