Part 1 of this topic was about medicine going beyond the borders of what is known by adopting the saying ‘One cause, one disease’. Now the question remains why medicine seems built around this odd and ambiguous saying while avoiding taking a stance on how the term ‘one’ in this saying should be conceived: identical, equal or similar.
More than ‘identical’ or ‘similar’, ‘equal’ introduces a sense of purpose. Indeed especially in medical practice the saying has a specific purpose. We will come to this purpose with the following thought experiment:
Thought experiment
Imagine you are going to become the first ever doctor. Your whole family has been terribly ill with agonizing belly cramps. Supposedly something was wrong with the stew all ate, including you. Unlike the others you had some special type of rare berries for desert none of your family members appreciate or even dares to eat. Surprisingly you only experienced some cramping but nothing really special. One week later a friend asks you some of those berries since he is experiencing terrible belly cramps for a day now. Upon your questioning he states he might have eaten some funny smelling leftover omelet. You wonder what logic justifies to give or refuse him these berries.
As a doctor it is your task to provide rational treatment even in the absence of full comprehension of the condition of the present case. To provide rational care you probably better apply some form of logic:
- Logically, action best is directed upon the cause, not at the effect. The treatment should therefore target the cause as close as possible.
- The use of experience from previous cases seems a form of implacable logic.
When it comes to using experience from previous cases one needs to make a series of interrelated assumptions.
- For instance, you will have to assume that the previous and present cases are at least equal, not just similar. Here you start using the idea of disease. It overcomes the individuality of cases and unites them into ‘one’.
- Assuming cases to be ‘the same’ is assuming each of these individuals has the disease in the same way. If each individual was to be totally unique every individual would be sick in its own unique way. With every individual being sick in its own way no disease could ever be recognized and there would be no logical foundation for any treatment.
- Also, you have to assume the cause is the same in every case. If a disease could be provoked by just any cause the diagnosis would not lead to a treatment that effectively targets the cause of this disease.
- Finally, you will have to assume all individuals respond to treatment in essentially the same way. If you wouldn’t assume individuals react ‘the same’ to treatment, there would be no logic in repeating successful treatments.
- To conclude: To base your actions on logic you need to consider individuals are equal or maybe even identical to each other, at least in respect to cause, disease and treatment.
You feel it is a bit of a long shot to reason your friend, you and your family members to be equal to such a point you all are almost identical but there is no other way for you to proceed. To use experience from previous cases you must accept ‘one cause, one disease’ as being true in anticipation of conclusive proof thereof. This proof would be a full explanation of this cause and disease.
In situations like this where it is impossible to prove things to be the same one might try to do the opposite: try very hard to prove things are not the same. If no argument can be found to tell these things apart from each other than default logic tells these things might be the same. This is the form of logic you have based your assumptions upon. The assumption individuals are virtually identical in respect to cause, disease and treatment.
Finally, you can find no conclusive argument to consider yourself, your friend and your family to be substantially different from each other in respect to cause, disease and treatment. Consequently, you all might as well be the same. You notice this is default logic again since you did not provide proof of all being ‘the same’; identical or equal. Despite this, logic seems to agree upon you giving your friend the berries. At least, if these berries do not pose a disproportional health hazard. But frankly, for the assessment of this hazard there is very little to go on. On the other hand you do not want to see your friend as terribly ill as some of your family members. You wonder weather the potential health gain from the berries outweighs the potential health risk posed by these very berries.
In the end, you decide to give your friend the berries. He pulls through after being moderately sick. With every future success of the berries the perception of ‘one cause, one disease’ might grow hand in hand with the perception of all individuals being equal in respect to cause, disease and treatment.
But ultimately, your friend pulling through, or any number of future cases pulling through, is not a very strong proof for your assumptions themselves to be true. With every new case of positive outcome after taking the berries only the odds for your assumptions being true will rise. Since these assumptions are being based on ‘One cause, one disease’, the success of your diagnosis and berry treatment will also increase the odds for ‘One cause, one disease’ to be true.
But no matter how successful your treatment is or how successful any treatment is, it will never prove your assumptions or that the basis for these assumptions to be true. With every new success the saying is just more likely to be true. Even all existing diseases being treated successfully will not be conclusive proof for ‘One cause, one disease’ to be true by itself.
It does proof however that medical practice does warrant rational decision making and does provide rational care.
It is here that becomes clear that medical practice and medicine are not ‘the same’. Medical practice has an existence in its own right. From this follows that medical practice has its own responsibility to continuously improve itself, improve treatments, improve patient outcome. We cannot expect medical practice to meanwhile think over what the treatment’s actual target is: disease, cause or the physical body of an individual. Nor is it up to medical practice to theorize on what ‘disease’ is, what is meant by ’cause’ or why cases of a disease are so similar. Unconditionally adopting the saying ‘One cause, one disease’ leads to a workable medical practice with tangible improvement of health outcome, however without taking a definite stance on how identical, equal or similar people are in health or disease.
2nd purpose
We have seen ‘One cause, one disease’ serves the important purpose of telling cases of a disease to be equal or nearly equal despite the absence of formal proof thereof. With a slight change of perspective, ‘One cause, one disease’ serves yet another important purpose. The purpose of telling your present case to be clearly different from cases belonging to other diseases. Seen from this second perspective, a disease being one means the cases belonging to this disease are clearly distinguishable from cases belonging to other diseases. This setting apart from other diseases is utterly important in medical practice since your options for rational treatment depend heavily on it. In this perspective of sharply distinguishing among diseases the cases belonging to one disease become more like identical to each other. Not merely equal as they appeared from the first perspective.
However, by forging the union of cause and disease in anticipation of their full explanation,
combined to the dismissal of the individuality of the human body from this very explanation,
medical practice leaves Medicine on an ambiguous position:
if taking shortcuts on logic and bypassing the scientific principle of assumptions requiring conclusive proof,
how is Medicine as a whole supposed to preserve its scientific rigour?
To salvage Medicine’s scientific rigour we propose to radically cut medical practice lose from the rest of Medicine. Medicine’s scientific rigour would not be flawed any more when reformulating the saying as follows:
“One cause, one disease is unarguably true, but only within medical practice”
It probably seems odd to set medical practice apart from the rest of Medicine in this formal way. However, Medicine would only follow the example of mathematics, probably the most explicit of all sciences. Diametrically opposed to medical practice, mathematics defines the truth prior to addressing the problem. Solving mathematical problems starts by stating:
“Although we cannot prove it we consider this and that to be true.”
These statements are called axioms and can be as simple as a + b = b + a. It is hard to believe no mathematician has ever been able to formally prove this statement. On the contrary, it is easy to see no instance will be found where a + b is not equal to b + a. This axiom seems being based on default logic much like we argued “One cause, one disease” is. The difference is that a + b = b + a feels way more logic than “One cause, one disease” does.
Much like our proposed rephrasing of “One cause, one disease” making it true only within the domain of medical practice, there also exist mathematical statements that are true only within a specific part of mathematics. Let’s take the example of imaginary numbers. Most will remember from maths education that taking a square root will always yield a positive number. Some specific mathematical problems however require the possibility of square roots to be negative numbers. This is the field of imaginary numbers. Imaginary numbers are composed of a real number and an imaginary part i which is defined in such a way that i2 = -1. Hence, the square root of the imaginary number 3i is -9.
3i2 = -9
Although Imaginary numbers are extremely useful, outside the domain of the imaginary numbers square roots yielding negative numbers are a total nonsense. If negative square roots cannot be generalized to the whole of mathematics, why should the idea of cause and disease being unquestionably ‘one’ be applied to the entirety of medicine?
(A real cool topic on how and why imaginary numbers were discovered:Veritasium)
From restricting the absolute truth of ‘One cause, one disease’ to medical practice alone will follow that all your assumptions required to treat your friend are no longer based on default logic but on plain solid, straight forward logic. But only for as long you reside within the field of medical practice.
Also, within the context of medical practice you do not have to discuss any more over subjects like what ‘a cause’ is, or how to define ‘disease’. All these difficult questions now have been transferred out of medical practice into that other part of medicine. This is the part of medicine that has to come up with answers to all the difficult questions. This also is the part of medicine that will have to solve what a disease is, what a cause is and to what extend individuals are ‘the same’ in the face of treatment, disease and cause.
In this newly defined domain of Medicine we will still be able to conceive diseases as ‘one’, each with ‘one’ single cause, but in a manner that is way more conceptual than precise. This conceptual definition of cause and disease might result in situations where diseases cannot always be clearly separated from each other. Nor will one single cause, as far as it can be conceived as ‘one’, stay solely related to one single disease in a very strict sense.
Even than, the proof of cause and disease being ‘conceptually one’ resides in a full explanation of how an individual human body can be the substrate for both cause and disease.