The real secret of happiness is simply this: to be willing to live and let live, and to know very clearly in one's own mind that the unpardonable sin is to be an unpleasant person.

The real secret of happiness is simply this: to be willing to live and let live, and to know very clearly in one's own mind that the unpardonable sin is to be an unpleasant person.

...the unpardonable sin is to be an unpleasant person.