Idiocy
Idiocy (id"i*o*sy) , noun
[From idiot; compare Greek {not transcribed} uncouthness, lack of education, from {not transcribed}. See Idiot, and compare Idiotcy.]
The condition or quality of being an idiot; absence, or marked deficiency, of sense and intelligence.
I will undertake to convict a man of idiocy, if he can not see the proof that three angles of a triangle are equal to two right angles.