Thanks to @MarkD I accidentally ran across the sermon, “Ultimatum,” from Kierkegaard’s Either/Or v.2. This is from near the beginning. Read it aloud. It’s easier to follow.
If I should speak in a different way, I would remind you of a wisdom you certainly have frequently heard, a wisdom that knows how to explain everything easily enough without doing an injustice either to God or to human beings. A human being is a frail creature, it says; it would be unreasonable of God to require the impossible of him. One does what one can , and if one is ever somewhat negligent, God will never forget that we are weak and imperfect creatures. Shall I admire more the sublime concepts of the nature of the Godhead that this ingenuity makes manifest or the profound insight into the human heart, the probing consciousness that scrutinizes itself and now comes to the easy, cozy conclusion: One does what one can? Was it such an easy matter for you, my listener, to determine how much that is: what one can? Were you never in such danger that you almost desperately exerted yourself and yet so infinitely wished to be able to do more , and perhaps someone else looked at you with a skeptical and imploring look, whether it was not possible that you could do more ? Or were you never anxious about yourself, so anxious that it seemed to you as if there were no sin so black, no selfishness so loathsome, that it could not infiltrate you and like a foreign power gain control of you? Did you not sense this anxiety? For if you did not sense it, then do not open your mouth to answer, for then you cannot reply to what is being asked; but if you did sense it, then, my listener, I ask you: Did you find rest in those words, “One does what one can”?
Or were you never anxious about others? Did you not see them wavering in life, those you were accustomed to look up to in trust and confidence? And did you not then hear a soft voice whisper to you: If not even those people can accomplish the great things, what then is life but bad troubles, and faith but a snare that wrenches us out into the infinite, where we really are unable to live–far better, then, to forget, to abandon every requirement; did you not hear this voice? For if you did not hear it, then do not open your mouth to answer, for you cannot reply to what is being asked about; but if you did hear it, my listener, I ask you: Was it to your comfort that you said “One does what one can”? Was not the real reason for your unrest that you did not know for sure how much one can do, that it seems to you to be so infinitely much at one moment, and at the next moment so very little? Was not your anxiety so painful because you could not penetrate your consciousness, because the more earnestly, the more fervently you wished to act, the more dreadful became the duplexity in which you found yourself: that you might not have done what you could, or that you might actually have done what you could but no one came to your assistance?
So every more earnest doubt, every deeper care is not calmed by the words: One does what one can. If a person is sometimes in the right, sometimes in the wrong, to some degree in the right, to some degree in the wrong, who, then, is the one who makes that decision except the person himself, but in the decision may he not again be to some degree in the right and to some degree in the wrong? Or is he a different person when he judges his act than when he acts? Is doubt to rule, then, continually to discover new difficulties, and is care to accompany the anguished soul and drum past experiences into it? Or would we prefer continually to be in the right in the way irrational creatures are? Then we have only the choice between being nothing in relation to God or having to begin all over again every moment in eternal torment, yet without being able to begin, for if we are to be able to decide definitely whether we are in the right at the present moment, then this question must be decided definitely with regard to the previous moment, and so on further and further back. Doubt is again set in motion, care again aroused[.]