to be believed

See: convincing
References in classic literature ?
We have only to add that the affairs of the captain have been satisfactorily arranged with the War Department, and that he is actually in service at Fort Gibson, on our western frontier, where we hope he may meet with further opportunities of indulging his peculiar tastes, and of collecting graphic and characteristic details of the great western wilds and their motley inhabitants.
To his thinking the navy was one of the current expenses of the war department, like the artillery, cavalry, infantry, and commissariat.
And though the war departments of the nations have continued to experiment in their secret laboratories, they have so far failed to light upon the slightest trace of the secret.