What is science? Is medicine and biology science? Let’s discuss

A regular commenter took off on the Economics is not a science discussion to suggest Medicine and Biology are not science. My answer below is, Sometimes and It Depends.


Much of medical and biological studies are observational and not do not qualify as science either.

Commenter says–It’s mostly just conjecture. “Well I suppose” leads to “maybe”. Not science.

People are talking about the movie “The Martian” and the phrase in there about “science the poop out of it” or something like that. Not science. Hard work, observation and engineering. In my dad’s day they knew the difference between science and engineering. Now anything even remotely technical is “science”.

Disagree with your dictionary definition. “3. any of the branches of natural or physical science.” Especially not. Also, “4. systematized knowledge in general”. Not. It’s science because it’s systematized? Huh? My grandkids legos are systematized in little bins but it’s NOT science. Good grief.

So, my turn.

In medicine we like the term evidence based and that means repeat, rinse, repeat and test your hypothesis against the evidence, that’s the critical scientific methodology.

In the complex world of biological structure and function, much of which is still not understood, there are lots of opportunities to to be wrong. Miss a confounder and your hypothesis is an empty one.

Good examples of biological science in action–Koch’s postulates for proving the cause of a disease, with particular emphasis on infectious diseases.

Another scientific method is the Bradford Hill rules on proving causation, for example beneficial or toxic effect, which look a lot like the Koch postulates for chemicals or physical effects on living organisms.

The Koch postulates can be used to disprove a cause of a infectious disease and modified to provide knowledge of non infectious diseases.

The Bradford Hill rules can be used to prove or disprove a toxic or beneficial effect of an exposure to a physical or chemical agent or condition. .

Koch’s postulates are the following:

1. The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms.
2. The microorganism must be isolated from a diseased organism and grown in pure culture.
3. The cultured microorganism should cause disease when introduced into a healthy organism.
4. The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

The Bradford Hill Rules can be turned for positive and negative evidence of effect, toxic or benificial.

The Bradford Hill Rules, from Wiki:

The Bradford Hill criteria for causation are a group of minimal conditions necessary to provide adequate evidence of a causal relationship between an incidence and a possible consequence, established by the English epidemiologist Sir Austin Bradford Hill (1897–1991) in 1965.

The list of the criteria is as follows:

1 Strength (effect size): A small association does not mean that there is not a causal effect, though the larger the association, the more likely that it is causal.
2 Consistency (reproducibility): Consistent findings observed by different persons in different places with different samples strengthens the likelihood of an effect.
3 Specificity: Causation is likely if there is a very specific population at a specific site and disease with no other likely explanation. The more specific an association between a factor and an effect is, the bigger the probability of a causal relationship.
4 Temporality: The effect has to occur after the cause (and if there is an expected delay between the cause and expected effect, then the effect must occur after that delay).
5 Biological gradient: Greater exposure should generally lead to greater incidence of the effect. However, in some cases, the mere presence of the factor can trigger the effect. In other cases, an inverse proportion is observed: greater exposure leads to lower incidence.
6 Plausibility: A plausible mechanism between cause and effect is helpful (but Hill noted that knowledge of the mechanism is limited by current knowledge).
7 Coherence: Coherence between epidemiological and laboratory findings increases the likelihood of an effect. However, Hill noted that “… lack of such [laboratory] evidence cannot nullify the epidemiological effect on associations”.
8 Experiment: “Occasionally it is possible to appeal to experimental evidence”.
Analogy: The effect of similar factors may be considered.

So, if you are honest about testing the postulates and the rules–you can produce reliable, reproducible explanations or you can prove up your hypothesis as valid. That’s evidence based science. You can’t cherry pick the rules however for the ones that work to prove your hypothesis. They come as a unit, and exceptions to the proof are less scientifically reliable. There are some exceptions, for example the organism sometimes are hard to culture in the case of Koch’s postulates.

A modification of the Koch’s postulates can provide diagnostic criteria for diseases that are not infectious.

If you hold to the rules, you can test a hypothesis, and in fact infectious disease, diagnostic nosology, pharmacology and toxicology can be made scientific.

Medicine is only science if it is scientific and evidence based–otherwise it may or may not be right based on observational anecdotal information or “fly by the seat of your experience or the experience of others,” but it is not scientific, evidence based medicine unless it is reproducible and falsifiable. When I say testable and reliably reproducible, that covers the Popper requirement that it be falsifiable.

An example of an organized effort to produce evidence based medicine is the Cochran Project that is devoted to gathering reliable medical research and identifying unreliable research.


Simple examples of the problem of reliable science in medicine is the confounder of an unknown or even known–some genetic unknown or the known problem of placebo effect. So that’s why when medicine gets serious it does Randomized Controlled studies that are blinded and placebo controlled to test drug effects.

In the case of the second inquiry–biology, the scientific knowledge of living things requires the use of chemistry, physics, and observational disciplines like anatomy and functional anatomy to determine both complex and not so complex functions of living things. Biology can begin with cold cuts, microscopic studies and chemical analysis to achieve reliable knowledge, but when we go to complex functionalities it gets harder.

One example is that at the cellular level anatomy and chemical functionality are not simple–they are as complex for the one-celled as the much more complex organism. No simple way to make DNA reproduce or membranes function properly, so bacteria have the same cellular complexities as the cell of an elephant or a human.


4 responses to “What is science? Is medicine and biology science? Let’s discuss

  1. The key point to defining a ‘science’ is that science itself may be defined as the application of the Scientific Method of deciding the verity of a statement.
    The Scientific Method (capitalized, because I wish to indicate that it is at least as important as any religion, almost all of which capitalize their own names to indicate the perceived importance) is a method of reproducibly, independently, and objectively checking postulates (i.e. proposed answers to questions) by interrogating the observable universe.
    Many science ‘educators’ and working ‘scientists’ are now as aware of this key point as they probably should be.
    Checklists such as Koch’s Postulates, the Bradford Hill Rules, and the FiLCHeRS criteria listed James Lett’s ‘Field Guide to Critical Thinking’ [http://www.csicop.org/si/show/field_guide_to_critical_thinking/] are helpful in certain circumstances, as is a good familiarity with the Fallacies of Informal Logic.
    Unfortunately many non-scientists and many poorly-trained ‘scientists’ focus on the results – what I think of as the ‘Lore’ of science – and unhesitatingly and uncritically accept whatever has been announced in the popular media as the Received Word.

  2. Probably more a matter of semantics. Although precision of definition is extremely important, niggling arguments over differing meanings attached to certain words seems like a particularly useless form of mental masturbation. It’s one of the reasons my eyes usually start to glaze over when reading philosophical arguments. I would essentially agree with everything the commenter and Tadchem wrote. Science is a method that can be applied to a number of different disciplines. I would consider both Biology and Medicine to be bodies of knowledge to which scientific principles may be applied. Just because most of the “studies” in the medical field are unscientific doesn’t disqualify it as a science.
    Koch’s Postulates have served as an attempt to apply scientific principles to the identification of causative organisms in infectious disease. But they have been recently abandoned and/or modified for reasons that have more to do with political correctness than science–e.g. HIV and AIDS.
    The Bradford/Hill criteria are mostly common sense. But I would strengthen the biological plausibility clause by stating that a biologically plausible cause and effect relationship must be an essential part of any viable theory. Limits on current knowledge may preclude a definitive linkage of cause and effect but it should be at least possible to propose a scenario that has some basis in current knowledge.

  3. “In medicine we like the term evidence based and that means repeat, rinse, repeat and test your hypothesis against the evidence, that’s the critical scientific methodology.” Ah, ok. Much closer. Now you’re talking. That’s all good stuff.

    From above, “Just because most of the “studies” in the medical field are unscientific doesn’t disqualify it as a science.” Don’t totally agree. If most of a subject is “unscientific” then it’s mostly not science. I also agree with ernestncurtis that the details can sometimes cause us all to glaze over.

    My point, I suppose, was that we’ve crossed a line. If most of the work in most fields is not science then we’re really not doing science and shouldn’t be saying that we are. And we shouldn’t be calling those people “scientists” and we shouldn’t be placing all our bets in false hopes. Or placing all our money on suppositional rhetoric.

    If you are observing something then say you are observing. Don’t say that you’ve figured it all out when you have nothing more than the early basics of a hypothesis (not even a theory). Like “climate science”. They have the first inklings of a hypothesis, almost no real data and yet they make predictions and state facts as if they “know”. It’s ridiculous.

    I got so tired of reading “scientific” evolutionary books that had things like, “well now suppose that…”, or “imagine that 2 million years ago…” this happened and maybe this happened and then maybe this happened. Aaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrrrrrrggggggggggggghhhhhh.

    Maybe I scratched an open wound. Sorry. I’m sure that the folks doing scientific medicine and following the processes that you mention above are all doing good stuff. Scientific stuff.

    All that said, it still may be true that the term “science” has become so debased in our culture that it’s almost unusable.

  4. Very nice. I agree. I didn’t say that all of medicine is scientific enough to meet our agreed upon methodology–much of it is not well studied and tested properly.

    I like your comment about evolutionists–they just bullshit their way along, confident that they have it figured out–selfish gene makes me wanna screeeem and I think it outrageous that they think anytime they run into a problem with “how” they can just say–well with enough time.

    evidence based medicine is real, and pretty good–strength of the research is rated, and such.

    You are right, a lot of medicine is observational without the testing to make sure.

    It is sometimes like flying by the seat of your pants–going with what others say works with some anecdotal but not solid and reliable “evidence” to go with.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s