doubtfulness

I dont bleve I could go way, said Dil, with soft-toned doubtfulness.

He approached his task with "great doubtfulness," fully conscious of the dilemma involved.

A man's apprehension may be true, when it is but a wavering opinion, with the greatest doubtfulness.

They tend to men's doubtfulness and uncertainty of their religion; seeing man is fallible, and so may his constitutions be.

Their present lack of cash, the doubtfulness of being able to sell and deliver the horses, made ransom a glittering possibility.