To be necessary, fit, becoming, or expedient; to behoove; -- in this sense formerly sometimes used impersonally or without a subject expressed.
Chaucer. [
1913 Webster]
" Ought is now chiefly employed as an auxiliary verb, expressing fitness, expediency, propriety, moral obligation, or the like, in the action or state indicated by the principal verb."
[1913 Webster]
"To speak of this as it ought, would ask a volume."
[1913 Webster]
"Ought not Christ to have suffered these things?"
[1913 Webster]