single-hearted

Instead of seeing in Mildred a possibly jealous woman, causing mental misery, she appeared a vision of single-hearted devotion.

That he loved power is surely no reproach to a statesman who used it as he did with single-hearted devotion to his country.

What is more at ease, more abstracted from the world, than a true single-hearted honesty?

To be crucified by those you have benefited is the cross of honour of all great, single-hearted men.

He was a simple, single-hearted man, moderate in all his views and wishes, and neither ambitious of distinction nor of wealth.