The best-interests standard is a widely used ethical, legal, and social basis for policy and decision-making involving children and other incompetent persons. It is under attack, however, as self-defeating, individualistic, unknowable, vague, dangerous, and open to abuse. The author defends this standard by identifying its employment, first, as a threshold for intervention and judgment (as in child abuse and neglect rulings), second, as an ideal to establish policies or prima facie duties, and, third, as a standard of reasonableness. Criticisms of the best-interests standard are reconsidered after clarifying these different meanings.