Other forms: impotences
Impotence is the state of being weak or unable to accomplish something, like the impotence of a broom in clearing a foot of snow from your sidewalk.
The noun impotence comes from the Latin impotentia, meaning “lack of control or power.” Though its most common definition is "the condition of not being physically able to have sexual intercourse," impotence can be any kind of physical weakness or ineffectiveness. You might present a very unconvincing argument. The impotence of your message may lead to not a single person agreeing with you.