dubitable

But the forms which logicians introduce, and which proceed from simple enumeration, are dubitable, and proceed only upon admittance— Y. Mir.

And there are further beautiful subtleties as to whether she really believes in this more kindly interpretation of the refined but dubitable Deshman….

But the merely dubitable is the already doubtful.

Her face grew grave for a moment before she turned upon Mr. Rogers that smile which, if usually latent and at the best not entirely feminine, was her least dubitable charm.

His motive in getting off the car was at least dubitable.