 Nevertheless, we can say that, just as with the Scholastic natural philosophy, there were adherents to the mechanical natural philosophy who postulated a single entity to play both the causal and classificatory roles; we can call these philosophers ‘corpuscular realists’ and we may say that they argue for the existence of what we might call ‘corpuscular species’, i.e., species created by nature by corpuscular forms. By contrast, again, Locke objects to this general approach for the creation of a scientific taxonomy: