The history of the law has seen a gradual expansion of the concept of “rights.”  People without land, prisoners of war, slaves, women and children were all once seen as “chattel,” or subhuman property, with none or few of the inherent rights to life, liberty and the pursuit of happiness enjoyed by full citizens.  The next legal and ethical frontier may well be the rights of animals, the mobile, sentient creatures with whom we share the Earth, and sometimes, our homes and lands. David Favre has taught law at Michigan State University since 1976, where he is the Nancy Heathcote Professor of Property and Animal Law.