(From foolish). Stupidity, idiotism. This may be styled a mental disease, sometimes owing to a more slow expansion of the mental faculties, which often, however, attain their powers suddenly, and in perfection, as suppressed irritability is followed by excess of excitement. When the mental powers are developed slowly, we often find a defective conformation of the cranium, and particularly an elongation of the upper part, while the sides are unusually depressed. Pinel, who scarcely admitted any organic defect to produce mania, admits it as a cause of idiotism. When in a less degree, it is not connected with any defective organization which the knife can discover.
Dr. Cullen considers this disease as synonymous with amentia. Sauvages makes it a species of amentia, and defines it a slowness or inability in the faculty of imagining or conceiving; consequently a debility in judgment without delirium. Stupidity differs from folly, as stupid or idiotic persons want both conception and memory. See Amentia.