What makes a species a species? Aristotle answered the species question by positing unchanging essences, properties that all and only members of a species shared. Individuals belonged to a species by possessing this essence. Biologists and philosophers of biology today are either not essentialists at all, or if they are think there are essences they are relational, historical properties. In his provocative book Biological Essentialism (Oxford UP, 2023), Michael Devitt argues for a new form of biological essentialism in which intrinsic essences, probably largely genetic properties, are part of what tie species together and that the actual explanatory practices of biologists commit them to this view. Devitt, who is distinguished professor of philosophy, emeritus, at CUNY Graduate Center, responds to many philosophers critical of his position, and applies his essentialism to debates about race realism and anti-realism.Carrie Figdor is professor of philosophy at the University of Iowa. Learn more about your ad choices. Visit megaphone.fm/adchoices