Questioning Expertise Credibility

   Expertise is a specialist knowledge and skill on a particular field which requires training and experience on it. A professional can be an expert on a particular field of it's work, for example a lawyer on family law or a doctor on surgery. Usually experts are consider highly credible compared to non-expert people, of course in their particular field of expertise. However there are various aspects in which we can rely to question the credibility of experts. Items A, B, C, D and E show some examples in which expertise was not very reliable.
    To begin with in item A we can focus on expertise as harmful in the medical area. Ivan Illich states that medical establishments can became a threat to population's health, they focus on treatments on how to fix people's problems but the main factors that affect health are housing, hygiene, diet and working conditions. By diagnosing and treating the illness, doctors seem to obscure what the real problem and it's source; they divert the attention from preventing the illness and focus on "fixing" it.  We can find in item B a good example: Tuberculosis illness started to decrease long before the medical treatments started. This is so because the source of the problem is in the hygiene or housing or lifestyle, not in the treatment. It's true that the treatment cures the disease, but that is not the real issue, the illness can be prevented.
    Furthermore on items C and D we can see examples of changing expertise. It changes together with adjustments in society; values and knowledge change, and that influences expertise. Item C talks about an alleged disease called "Drapetomania", Dr. Samuel Cartwright discovered this "disease" which took place on black slaves, this was supposed as a mental disease that needed to be treated. But, actually as years passed and values and knowledge changed, doctors realised this was not actually a disease. Moreover on Item D we can see a similar example with the supposed "mental illness" of homosexuality. Not so long ago, doctors believed that gay people were sick and needed to be treated and could be cured. Nowadays we can clearly see that is not true, sexuality is just a matter of interest and attraction, not an illness.
   As a conclusion, experts may have seen homosexuality as a disease, just as "drapetomania" because of the values and studies of that moment, but this doesn't mean they were right. Expertise can be based on prejudice, it is too attached to the time and place and this affects it's credibility. Something can seem to be true at the moment, but will it still be true on the future?