Grice to the Mill ("sous-entendu")

"No shadow of justification is shown...for adopting into logic a mere
sous-entendu of common conversation in its most unprecise form. If
I say to any one, "I saw some of your children today", he
might be justified in inferring that I did not see them all, not
because the words mean it, but because, if I had seen them all, it is
most likely that I should have said so: even though this cannot be
presumed unless it is presupposed that I must have known whether the
children I saw were all or not."

(from "Examination of William Hamilton's Philosophy", 1867)