Science and Pseudoscience, truth and opinion

The English word “science” is primarily used about the natural sciences. We like to warrant our knowledge claims as being true by citing their scientific basis. We use the word “pseudoscience” to describe those studies whose knowledge claims are mistakenly regarded as scientific truths. We mean to say that their claims are closer to opinions. For example, many people think dowsing, or water divination, is a pseudoscience.

Discerning between scientific and pseudoscientific knowledge claims is critical to many situations. It is legitimate to take preventive measures when there is valid but yet insufficient evidence of an environmental hazard. For example, the oceanographers’ prediction that an oil spill may land on a specific part of a coastline. This must be distinguished from taking measures against an alleged hazard for which there is no valid (scientific) evidence at all.

Philosophers have long been interested in what they call the demarcation problem: the problem of how to demarcate science from non-science. But over the years they have become less and less certain about their answers. One of the earliest responses to the problem came from Aristotle who proposed two demarcation criteria. First, he said that science is distinguished from opinion and superstition by the certainty of its principles: a science produces laws that are absolutely certain.

Second, Aristotle said that science can demonstrate a reliable understanding of all the causal chains in a process. Disciplines that could not answer this question in a reliable way were not sciences in Aristotle’s definition of the term. For example premodern astronomers thought they had proved that the sun revolves around the earth. They developed many complex explanations of how the earth caused the sun and other heavenly bodies to behave the way they did. To the extent these turned out to be unreliable we now look back at premodern astronomy as a pseudoscience.

By the mid-nineteenth century, most philosophers realized that science did not offer absolute certainty. In fact, all scientific theories are subject to significant change over time and are thus fallible. Consider the law of the sun revolving around the earth. Philosophers then moved to an argument that what really marks science off from pseudoscience is something called the ‘scientific method’. But it turned out that they could not reach any shared definition of the required components and characteristics of a scientific method. There have been other proposals of what makes science but, as of today, there is no universal agreement, or absolute certainty.

Today this problem rarely concerns those in the quantitative social sciences. They dismiss the philosophers’ concerns as omphaloskepsis (navel-gazing) and they get on with the work at hand.


They generally accept that much of their social or economic research does not yield absolute certainty. They recognize that there will be changes in social or economic behaviors that are not explained by their previous claims. They continually discover new causal variables or interactions they did not previously recognize or understand so that their most general, high level laws are perverted by what they blithely call ‘noise’. This is one reason social and economic predictions are notoriously difficult to make with any but the most general level of reliability. Prediction is most reliable after the fact.

But this is not to say that research done by social scientists is not valid or useful as a warrant for knowledge claims. They do provide the basis of a demarcation between opinions and facts in economic or social debates. More on this in the next blog, Sociology and Journalism.

3 thoughts on “Science and Pseudoscience, truth and opinion

  1. Ray

    The term “absolute certainty” is pleonastic in the ultimate purport.

    The word science comes from the Latin sciēns, which means “to know.”

    Scientia is the Latin word for knowledge.

    There are the technical sciences. There are the physical sciences. There are the social sciences. There’s the science of math. There’s even the science of knowledge, which is called epistemology — from the Greek Episteme which also means knowledge, and which is a subdivision of the more general science of philosophy. There are of course many, many others.

    The demarcation question is purely epistemological, and “general acceptance,” as you say, is hardly a legitimate criteria for knowledge.

    Knowledge is the accurate recognition of reality.

    When, for instance, a child observes that two oranges combined with two more oranges make a total of four oranges, that child has just gained knowledge: she has accurately identified a fact of reality.

    The two principles one must always remember about knowledge are these:

    It is contextual.

    It is hierarchical.

    For this reason, newly discovered knowledge by definition will not and cannot contradict already established knowledge.

    To make this point more explicit, imagine a child learning what the term “human being” is. Perhaps the child’s first definition is this:

    A human being is a creature that has thumbs.

    Well? That is true. Humans do have thumbs — unique thumbs — which indeed are a part of our definition. That child has discovered knowledge, and because it is knowledge, newly discovered knowledge cannot contradict it.

    Suppose that same child then sees an orangutang with opposable thumbs. So she refines her definition to this:

    A human being is a living creature with thumbs that does not (as a rule) walk on all fours, as against horses and dogs and cats and so on.

    What of that? Well, it is accurate too. That, therefore, constitutes knowledge. Why? Because it is accurate. Veritas est adaequtio rei et intellectus.

    The child has made another correct observation — specifically, she has accurately observed something about reality, and bipedal motion is indeed another of the distinguishing things about humans — and so is the fact that humans are alive.

    Then suppose the child sees gorillas and bears and monkeys all alive and walking bipedal with thumbs. The child, therefore, refines her definition to this: a human being is a living creature that doesn’t walk on all fours and who isn’t covered in hair.

    And that is accurate as well. This is knowledge.

    Supposed the child next observes that humans use language.

    Suppose she follows this very process over the course of years into young adulthood, constantly refining her definition, until she arrives at this:

    A human being is a primate with a conceptual faculty.

    As long as the child’s observations don’t contradict the facts — i.e. don’t contradict reality — then newly discovered knowledge (i.e. her expanding context and the hierarchy of her knowledge) won’t contradict what she’s already discovered. Why? Because what she’s discovered is accurate. It is true. It is knowledge.

    If it does contradict, it was not accurate knowledge — i.e. her observations were incorrect. For instance, if a child defined a human as “a reptile who lives underwater,” that is not, strictly speaking, knowledge. Why? Because it is incorrect.

    Note the fundamental underpinnings to this abbreviated example of the epistemological process: observation and correspondence to reality.

    All science, whether experimental or not, must start (and end) with observation: specifically, the observation of evidence.

    In this way, certainty is possible — indeed commonplace — but one must always hold the context in one’s mind. (Some philosophers qualify this as a “contextual absolute.”)

    It is, in other words, certain that two oranges combined with two more oranges make a total of four oranges.

    1. father time Post author

      A modest reply to a rich comment. (I think I will try to limit my replies to less than half the word count of the original post. In that way I can avoid a tendency toward unchecked, geometric growth that characterizes my comments so far, and cancer.)

      R: Knowledge is the accurate recognition of reality.
      FT: Agreed with one reservation. “Accurate” satisfies the ’true’ requirement in the definition of knowledge as justified true belief. You thus subscribe to the correspondence theory of truth: true statements align with what is the case. But perhaps we can leave theories of truth for another day?

      R: Newly discovered knowledge by definition will not and cannot contradict already established knowledge. …
      FT: Agreed. Any contradictions automatically debase earlier knowledge claims, and thus, science is fallible.

      R: Your series of examples of a child expanding its knowledge.
      FT: Agreed, science tends to accumulate a body of justified true beliefs with an occasional paradigmatic change: e.g. heliocentrism.

      R: All science, whether experimental or not, must start (and end) with observation.
      FT: The empiricist school of philosophy agrees with you.

      R: In this way, certainty is indeed commonplace — but one must always hold the context in one’s mind.
      FT: Many philosophers argue that to call a truth absolute is to claim that it is an eternal idea in the mind of God, true across all contexts. If, as you say, ‘certainty’ can apply to claims that only occur in some contexts then there might be room for ‘absolute certainty’ to designate certainty across all contexts.

      R: It is, in other words, certain that two oranges combined with two more oranges make a total of four oranges.
      FT: Agreed. 2+2=4 is considered a necessary truth that operates across all contexts.

      Thanks for your reply, FT.

  2. Ray

    “You thus subscribe to the correspondence theory of truth”


    “But perhaps we can leave theories of truth for another day?”

    Yes, we probably better.


Leave a Reply

Your email address will not be published. Required fields are marked *