Noun
The state or quality of being ingenuous; openness of heart; frankness.
Ingenuity.
Source: Webster's dictionaryIt would be a piece of ingenuousness to accuse the man of today of his lack of moral code. The accusation would leave him cold, or rather, would flatter him. Immoralism has become a commonplace, and anybody and everybody boasts of practising it. José Ortega y Gasset
Then shall I awake to the primitive fervour, Straight and alone, 'neath antique floods of light, Lilies and one of you all through my ingenuousness. Stéphane Mallarmé
Through the ingenuousness of her age beamed an ardent mind, a mind not of the women but of the poet; she did not please, she intoxicated. Alexandre Dumas