“The question of who can speak for the animals has long vexed federal judges in animal-welfare cases,” a judge in the federal District Court for the District of Columbia has written recently. “As a general matter, courts have concluded that well-established principles of Article III standing permit human beings to invoke their own injuries in fact to challenge harms done to animals, but it can be exceptionally confusing to apply settled standing doctrine to determine when and under what circumstances an act that is allegedly harmful to animals works a cognizable injury in fact to human plaintiffs.” The issues arose in a case in which the New England Anti-Vivisection Society and a number of...