not impossible

See: allowable
References in classic literature ?
It is not impossible that this conceit occurred to Hawthorne before he had himself seen the Old Man of the Mountain, or the Profile, in the Franconia Notch which is generally associated in the minds of readers with The Great Stone Face.
The object of knowledge would appear to exist before knowledge itself, for it is usually the case that we acquire knowledge of objects already existing; it would be difficult, if not impossible, to find a branch of knowledge the beginning of the existence of which was contemporaneous with that of its object.
It was not impossible, he observed, that these cannon might have been fired by the savages themselves.
When on the verge of submission to these opinions, the small duel had showed them that the propor- tions were not impossible, and by it they had revenged themselves upon their misgivings and upon the foe.
The most that the public can know, is that the governor claims the right of nomination; that two out of the inconsiderable number of four men can too often be managed without much difficulty; that if some of the members of a particular council should happen to be of an uncomplying character, it is frequently not impossible to get rid of their opposition by regulating the times of meeting in such a manner as to render their attendance inconvenient; and that from whatever cause it may proceed, a great number of very improper appointments are from time to time made.
As the Indian agent of New York had a log dwelling at the foot of the lake, however, it is not impossible that the appellation grew out of the meetings that were held at his council fires; the war drove off the agent, in common with the other officers of the crown; and his rude dwelling was soon abandoned.
I will venture to say, that for a man to act in direct contradiction to the dictates of his nature, is, if not impossible, as improbable and as miraculous as anything which can well be conceived.
It abounds in the Rocky Mountains, from the fiftieth degree of north latitude, quite down to California; generally in the highest regions capable of vegetation; sometimes it ventures into the valleys, but on the least alarm, regains its favorite cliffs and precipices, where it is perilous, if not impossible for the hunter to follow.
And now we say not only that our laws, if they could be enacted, would be for the best, but also that the enactment of them, though difficult, is not impossible.
But as the larger States will always be able, by their power over the supplies, to defeat unreasonable exertions of this prerogative of the lesser States, and as the faculty and excess of law-making seem to be the diseases to which our governments are most liable, it is not impossible that this part of the Constitution may be more convenient in practice than it appears to many in contemplation.
If he succeeded," said he, "which is very improbable, but not impossible -- for everything is possible in this world -- what would you advise him to do?
It is not impossible that he was affected with the transcendentals.