 A first step to understanding these reasons involves noting a further ambiguity in the use of the expression “human nature”, this time an ambiguity specific to taxonomy. The term can be used to pick out a set of properties as an answer to two different questions. The first concerns the properties of some organism which make it the case that it belongs to the species Homo sapiens. The second concerns the properties in virtue of which a population or metapopulation is the species Homo sapiens. Correspondingly, “human nature” can pick out either the properties of organisms that constitute their partaking in the species Homo sapiens or the properties of some higher-level entity that constitute it as that species. Human nature might then either be the nature of the species or the nature of species specimens as specimens of the species.