harmful, outcomes. As an antidote, MacAskill and his colleagues developed effective altruism-a practical, data-driven approach to doing good that allows us to make a tremendous difference regardless of our resources. Effective altruists operate by asking certain key questions that force them to think differently, set aside biases, and use evidence and careful reasoning rather than act on impulse. In Doing Good Better, MacAskill lays out these principles and shows that, when we use them correctly-when we apply the head and the heart to each of our altruistic endeavors-each of us has the power to do an astonishing amount of good.