rationalskepticism.org

if there is no obvious underlying physical pathology, investigations must continue until it is rendered obvious, which is why medical science and biology in general has not come to a standstill, but then again, "obvious" is a term that is very much grounded in the inadequacies of our current diagnostic and analytical tools to pinpoint it.

Now, you argue it is unobtainable, care to back that up with evidence?