Aquinas spoke of piety in the context of one's parents and country, and given the obligation to accord each what is rightfully due them, related it to the cardinal virtue of justice. (By analogy, rendering to God what is due him, Aquinas identified as the virtue of religion, also related to justice.) Professor Richard McBrien said of piety that, "It is a gift of the Holy Spirit by which we are motivated and enabled to be faithful and respectful to those -- ultimately, God -- who have had a positive, formative influence on our lives and to whom we owe a debt of gratitude," and requires one to acknowledge, to the extent possible, the sources of those many blessings through words and gestures great and small.
