IMPOTENCE; IMPOTENCY n. 2 definitions
leness; inability; imbecility. Some were poor by impotency of nature; as young fatherless children, old decrepit persons, idiots, and cripples. Hayward. O, impotence of mind in body strong! Milton.
INCOMPETENCE; INCOMPETENCY n.
cal, intellectual, or moral ability; insufficiency; inadequacy; as, the incompetency of a child hard labor, or of an idiot for intellectual efforts. "Some inherent incompetency." Gladstone.