Everytime someone enters a plea of insanity for a crime you have a psychological expert for the prosecution testifying that the accused is sane. Then the defense will bring in their expert who will declare that the accused is insane. The jury will then decide the issue based on which expert's credentials were more impressive or which one they liked the most. I think it shows that the science of psychology is still in its infancy, where consensus can not be achieved for lack of stable concepts.

The US legislature brought several Generals to testify that Secretary of Defense Rumsfeld was ruining the capabilities of the US's armed forces with his actions. Whether Rumsfeld's actions in regard to the military were proper or not, I can speak to the issue of the competency of the Generals. There is a saying "Old Admirals want battleships and old Generals want horse cavalry." which is another way to say they are preparing for the last war they were in and not something new and different. The City Fathers of Carthage were probably being urged by Hannabil to train more "war elephants" as Africanus was dreaming up new tactics to make them obsolete.The Knights of France were probably clamoring for more horseman as the English long-bowmen were marching into France to make the Knight obsolete. In the height of a world depression, France was spending great sums of national treasure on building the Maginot defenses, still in the mind set of the last war, and the German High Command was planning to circumvent the line and did. Generals are the worst counsel to seek about National Defense.

During the !800's the most notable scientist at that time was giving an interview to a newspaper and answered the question about man in space "...as utter hogwash", that it would violate physics. At that time, with the knowledge base of that time, that scientist was correct. An expert whose parameters were correct but incorrect. Time moves on and so does knowledge unless you listen to experts.