 Let us turn to a popular view among philosophers and biologists concerning the ontological status of species. Ghiselin (1974) and Hull (1978) suggest that instead of viewing species as natural kinds we should think of them as individuals. Hull draws the ontological distinction this way. (Instead of the phrase ‘natural kind,’ Hull uses the term ‘class.’) Classes are groups of entities that can function in scientific laws. One requirement of such laws is that they are true at any time and at any place in the universe. If ‘All copper conducts electricity’ is a law, then that law is true here and now, as well as 100,000 years ago on some distant planet. Copper is a class because samples of copper are spatiotemporally unrestricted —copper can occur anywhere in the universe. Individuals, unlike classes, consist of parts that are spatiotemporally restricted. Think of a paradigmatic individual, a single mammalian organism. The parts of that organism cannot be scattered around the universe at different times if they are parts of a living, functioning organism. Various biological processes, such as digestion and respiration, require that those parts be causally and spatiotemporally connected. The parts of such an organism can only exist in a particular space-time region. In brief, individuals consist of parts that are spatiotemporally restricted. Classes consist of members that are spatiotemporally unrestricted.