unassailably

It was respectable; it was unassailably effective; it was not included in the Commandments.

The girl smiled with pleasure, but Clarke remained so unassailably serious that Serviss was moved to further deeps of audacity.

Until faith in these fundamental truths has been unassailably established, no basis for Christianity has been secured.

As the daughter of Blackford Singleton she considered herself unassailably a member of the upper crust of the Hoosier aristocracy.

But definite, I think—utterly and unassailably definite—although quite Christian-Scientifically foggy in its phrasing.