Differential diagnosis and mental illness

In considering the argument that Thomas Szasz advances on behalf of his claim that there is no mental illness, it becomes evident that despite his stated assumptions, moral valuations are necessarily tied up with assessment of disease. By following his remarks about differential diagnosis, it becomes evident that behavior is the occasion for differential diagnosis, that behavior determines which anatomical deviations are counted as diseases, and that Szasz's insistence on autonomy introduces his own moral assumptions into the concept of disease. Consequently, although none of these considerations disproves Szasz's conclusions about the existence of mental illness, neither can his argument support the weight of that conclusion.