"In fact, this was one of the artifices to which the genius of the Greek language had recourse, to avoid speaking presumptuously of the future: for there is an awful, irrepressible, and almost instinctive consciousness of the uncertainty of the future, and of our own powerlessness over it, which, in all cultivated languages, has silently and imperceptibly modified the modes of expression with regard to it: and from a double kind of litotes, the one belonging to human nature generally, the other imposed by good-breeding on the individual, and urging him to veil the manifestations of his will, we are induced to frame all sorts of shifts for the sake of speaking with becoming modesty.
"The English Language"
Robert Gordon Latham
It is possible that he may have used some expressions in an oblique sense; there are several kinds of cases where this occurs: allegory and symbolism, jests and hoaxes, allusion and implication, even the ordinary figures of speech, metaphor, hyperbole, litotes.
"Introduction to the Study of History"
Charles V. Langlois Charles Seignobos