Last Updated September 5, 2023.
Purity of Heart Is to Will One Thing is a sermon about goodness. The opening condemns "double-mindedness," which, as we are to learn, represents willing more than one thing, or willing anything besides Good. Kierkegaard spends a paragraph making sure the audience doesn't worry that willing only one thing might interfere with their lives, because the ways their wills direct them down their paths still points them to Good.
Kierkegaard believes that all paths point to Good because all people have good inherent in them. This also means that no one can simply choose to will against the Good: they can only be double-minded.
Kierkegaard blames this double-mindedness on academic education, which he says conceals the Good and calls it by other names so that people become confused. He also calls into question people who claim to want any singular thing besides Good, because he says that each of these desires actually represents a multitude of complex and often contradicting wants, and that no pleasure besides the satisfaction of Good can actually be satisfying in the long term—especially not into death.
The power of the Good is so thoroughly a part of people, even those who try to avoid it, that Kierkegaard says that this is a defense mechanism for God, because no one can fully rebel without being held back in hesitation by the Good inside them.
Kierkegaard finally exhorts people to give up the idea that they will become successful if they will any one thing—be it good or bad—because exerting consistent control is how man expresses his greatness. He reiterates that earthly values and success are meaningless, and that the only truly consistent thing to will is Good. He ends the sermon with a reminder that if someone seeks to will Good and misses the mark, they will nevertheless find the path eventually, because all roads lead to Good.