With coding and math, you have clear-cut, correct answers that you can check, William Isaac, a research scientist at Google DeepMind, told me when I met him and Julia Haas, a fellow research scientist at the firm, for an exclusive preview of their work, which is published in Nature today. That’s not the case for moral questions, which typically have a range of acceptable answers: “Morality is an important capability but hard to evaluate,” says Isaac.