"He who, in the study or the treatment of the human machinery, overlooks the intellectual part of it, cannot but entertain very incorrect notions of its nature, and fall into gross and sometimes fatal blunders in the means which he adopts for its regulation and repair. Whilst he is directing his purblind skill to remove or relieve some more obvious and superficial , the worm of may be gnawing inwardly and undetected at the root of the constitution."