I like the defintion of disease as you have presented it, and it is a nice clear one. I did not mean that you were a strident one, although i did not make that clear.
However in common usage the disease concept is one of a number of different things
-an infection of some sort
-a 'malfunction' or 'not functioning' as intended in a biological system
-impairment in functioning or decrease in functioning in a biological system
-a function in the system that has detriment to the health of the organism.
You are correct. Common usage indeed conotes these things; I would go further to suggest that in general vernacular, 'disease' also carries an implication of being contagious, hence the common application of the term 'to catch' when it comes to acquiring a disease.
The point is, the term disease as used in pathology has a rather broad definition. You can point out 'common definition' for a term, but in science we avoid such connotative language in the name of limiting ambiguity.
My disagreement would be on what constitutes a deviation in normal functioning when it comes to behavior, I think you will note that I have stated there is a biological basis to human behavior and i am a strcit materialist.
Of course, this is always a sticking point when it comes to describing something as a disorder or disease. 'Normal' functioning is not a strictly contained point, but rather a spectrum, and defining where the boundaries lie is rather arbitrary. I also believe that behaviour is a biological function (it can't really be anything else) that relies on the interactions of our biochemical and nervous systems. Variation in this produces variation in behaviour.
So, is an addiction outside of 'normal' functioning? If normal is defined as a set of characteristics as expressed by a majority of a population, then I would argue that addiction is abnormal. More people are not addicted to alcohol, in that it influences their decisions and behaviour, than are.
The second part of the definition - where this variation impedes well being - can inarguably be applied to alcoholism. The wellbeing and sense of satisfaction that addicts have with their lives, as a result of the variation in function, is reduced due to the influence of their behaviour.
There are those who are driven to addiction through the biology of thier system, but as a behavioralist who agrees that we are solely biological mechanisms. I do not believe that behavior is soley deterministic, i do believe that there is aan element of perhaps constrained choice in the system. So while I agree that behaviors can lead to deviations in the biological norm of the system, i also believe that there are things in behavior that are not determined solely by the functioning of the system
Which is at the crux of your argument. And fair enough, too. I personally cannot abide by any ghost in the machine; all behaviour - free will or otherwise - is controlled by biological functioning. If the variation in my thinking, influenced by past experiences, environment, neural structure, genetics...whatever... deviates greatly from the norm and reduces my sense of wellbeing, it fits the definition of disease.
Indeed, if you do not consider thinking or behaviour to be the result of biological function (which I can't see how it isn't), then the term disease will not suit addiction. However, it would also not suit many, if any, other psychological conditions.
Therefore, how would one draw a line between, say, schizophrenia (which is commonly accepted as a mental disease) and addiction?
In short (because I have to leave for work and I am sure this is not the clearest i can state my unorganised thinking at this time) there are things that are behavioral that are driven by the biological system (mental illness such as schizophrenia) and there are those that are driven by choices made in the cognition and actions of the biological entity. So while I agree that behaviors can lead to disease , the oft cited diabetic with poor diet, I think that there are those behaviors which lead to a deviated biological function that are not driven by just the functioning of the system.. I don't know how to keep that from becomeing a free will argumement.
And certainly that is a circular mess of defintions i made that will need revising and modification and through examination probably toatl renovation.
Of course. Thank you for taking the time to explain what you mean so carefully. It does make a difference, and rather than quibbling back and forth over 'it is / isn't a disease', we can see the real crux of where we disagree; that cognition and choice of actions in a biological entity either is or is not (depending on our respective stances) the direct result of biological functioning.
Athon