simple-mindedness

Even the one negative connotation, that of simple-mindedness, produces a stock response of sympathy.

Perhaps, however, the point which strikes one most is the amazing simple-mindedness of the whole proceeding.

She kept perpetually within her sight his unselfishness, his patience, his simple-mindedness, his devotion.

Our simple-mindedness pleases them as a bit of unspoilt nature, and it is just by means of that that they deceive us.

With the whole force and passion of his nature, with all his single mindedness—would some call it simple mindedness?

They accepted his gruffness as simple-mindedness, as blunt honesty.