Theories, Hypotheses, Opinions, and Beliefs
The purveyors of pseudoscience frequently use linguistic gymnastics to give their claims an air of legitimacy. The technical differences in terms used interchangeably in common parlance may be irrelevant to anyone not looking to pick a pedantic fight. Unfortunately, they can be intentionally misused to equate to very different concepts and put them on the same level – cheapening one and unfairly validating the other. Depending on how they are used, those seeking to educate may take different approaches.
The misuse isn’t always intentional – I’ve heard terms repeated by well-meaning individuals who generally don’t understand the scientific method. Statements like “Well, it’s your belief that homeopathy won’t cure my Crohn’s and it’s my belief that it will, so it’s just as likely that I’m right” are hard to combat because they show the speaker lacks any grounding in how science works in general. Attacking belief with fact is not likely to be fruitful without laying the groundwork. Because the individual has a strong stance on homeopathy, you are better off trying to explain the scientific method in another area where they have neutral beliefs before talking about homeopathy treating IBD.
If a person is well educated and has perhaps a blind spot for a particular area of snake oil (let’s call it the Pauling effect), a different approach may be necessary. The person may say something like “I’ve got a PhD in astrophysics and I’ve read the facts differently than you and it is my opinion that the cosmic ray theory of Crohn’s Disease is correct*”. In that case, the person is applying an opinion that they are allowing to override evidence, calling something a theory that may only exist in their head, and probably only reading information that supports their already formed beliefs (an example of confirmation bias). Because the individual understands the scientific method, there may be a better way of confronting them. Instead of providing counterarguments, it may be more fruitful to ask them questions about their belief that provoke self-reflection – “I’m interested in cosmic rays. How do they relate to x-rays? Would x-ray radiation also cause Crohn’s disease, then? Are people who fly frequently more likely to get Crohn’s disease? What about astronauts?” Additionally, listen to their answers – if they have solid, new evidence to support their assertion, then it bears consideration.
The final misuse category is intentional, and is used by individuals where they have little or no evidence to back up their claims and they know it so they create a false parity as substitute. This can be the mark of a snake oil salesman (or just plain ignorance), but usually goes something like this “It is your theory that treating inflammation with Western medicine like the biological drugs helps out with IBD. My theory is that acupuncture is a valid treatment for IBD. We both will just have to agree to disagree on who is right. What I will say, though, is that acupuncture doesn’t have the side effects that the biologicals do and it is a lot cheaper.” While sounding magnanimous, this individual is taking a practice that has no grounding in the current understanding of anatomy, and equating it to the application of a treatment that is evidence based and supported through double blind trials repeated by independent researchers. Additionally, they have applied a straw man approach – they have moved the discussion from whether or not acupuncture is effective to one where they are comparing the side effects (many placebo treatments have no direct side effects, only the harm caused by inaction – see http://whatstheharm.net/ for cases where “harmless” treatments have had less than desirable results). Folks making these claims are not likely to be educated – you may be better off educating individuals that are making use of their “services”.
What is the difference between the terms in the title of this post?
Let’s deal with hypothesis first. A scientific hypothesis is sometimes equated to a guess, which is inaccurate. A hypothesis starts with observations and a theory of action that is grounded in science. Based on the observations, a precise statement is made that is testable. The method to forming a hypothesis might be something like the following:
1. A doctor observes numerous IBD patients in her practice. It appears, through observation, that many of the patients are suffering from anemia.
2. Previous studies have shown that blood loss from other conditions can cause anemia. The doctor has observed increased blood loss in the patients that have been anemic.
3. The doctor hypothesizes that blood loss due to IBD causes a higher incidence of anemia amongst those with IBD.
For a hypothesis to be valid, it needs to be testable and falsifiable. If it is not testable, there is no way to provide evidence to confirm the hypothesis. It must also be falsifiable – capable of being proven false. A hypothesis like “The magic of prayer causes intestinal healing, but getting tested to show the level of inflammation indicates a lack of faith, preventing the healing.” While the statement may sound off the wall to anyone reading this blog, there is a large portion of the population that would not find it so. Unfortunately, the statement does not qualify as a hypothesis because it is inherently non-testable (how do we measure “prayer”?) and non-falsifiable (any attempts to disprove the power will be self-referentially the cause of the failure).
A hypothesis leads to testing – hypotheses are not “proven”, they are tested or evaluated. When testing, evidence and not “proof” is gathered. In fact, a good scientist will seek to design studies that would invalidate their hypothesis if the evidence does not support it. In medicine, placebo controlled double blind studies with large, representative samples have best track record in testing hypotheses without introducing bias.
A scientific theory is an explanation that starts out as a hypothesis, and undergoes rigorous testing. Throughout the testing, the evidence is objectively weighed against the original hypothesis. If, after extensive testing including independent confirmation all of the evidence supports the hypothesis, then it becomes an accepted theory. Theories provide a tested explanation based on what the evidence shows. There is no element of belief or opinion present. Additionally, a valid theory is based on tests that can be replicated by anyone using a valid protocol. Theories do not need to explain every aspect of a situation, and there can be competing theories that are supported by evidence. When competing theories are present, it is generally because the current state of the science hasn’t adequately identified enough evidence to disprove one of them. Theories can and do evolve as better testing methods and more rigorous applications of the scientific method become available (as opposed to dogmatic beliefs, which leave no room for change). Once a scientific consensus has been reached (note: a consensus is a general agreement between the majority of educated practitioners in an area based on the supporting evidence for a theory – it does not require unanimity nor does it take the Family Feud approach by allowing for a theory to be a popularity contest not backed by evidence).
Opinions and beliefs have nothing to do with theories. Theories are accepted, not believed (belief is a “trust, faith, or confidence in someone or something” – note there is no requirement for rationality, reason, or evidence). A lawyer I knew once said “The two statements that have no place in the law are ‘I believe that…’ and ‘I feel that…’”. The same holds true for science.
Although they are similar, opinions are beliefs that are backed up by evidence. The evidence may be subjective, incomplete, or erroneously interpreted. They may also be based on hard evidence. Unfortunately, because opinions can be based on solid grounding, weak grounding, or even completely irrational grounding, they are more difficult to pin down. An expert opinion can be as precise as a physician opining that an individual has Crohn’s disease due to the presence of intestinal inflammation, granuloma formation, and symptoms consistent with the disease with the lack of other proximate cause. Unfortunately, many individuals are of the opinion that they have various diseases without going through any rigorous testing protocol “It’s my opinion that I have a gluten allergy because the day after I ate that large pizza my stomach was upset”. Opinions, unlike beliefs, tend to be easier to form and easier to un-form. A good physician is always willing to reconsider or revise a medical opinion as new evidence becomes available.
· While a philosophy lecture is more likely to discuss the uses of the terms hypothesis, theory, opinion and belief, their misuse can sow confusion for patients about what is and is not science-based medicine.
· Practitioners and patients should be cautious about their own use (and misuse) of the terms, whether intentional or accidental.
* I’m unaware of any cosmic ray theory of IBD, though the intestines are particularly susceptible to radiation. That fact alone, though, doesn’t even make the concept a complete hypothesis, let alone a theory.