A Study On John Locke's Thoughts Of Natural Kinds

Natural kinds have been an important issue which attracted the attention of many philosophers in recent decades.What are natural kinds? Are they defined by essence? And do they really exist in nature? With regard to these issues,contemporary philosophers have engaged in heated debates and proposed many different theories and views about them.The history of natural kinds can be traced back to Plato's “Idea” and Aristotle's doctrines on substance and essence,and revived contemporarily with natural kind semantics proposed by Kripke and Putnam.However,among the historical development of natural kinds,Locke's view of natural kinds has been ignored.In fact,Locke makes much discussion on the formation of kind and the nature of natural kinds.On the one hand,his views of natural kinds can help us understand some of the contemporary controversies over natural kinds.On the other hand,re-examining Locke's position of natural kinds within the contemporary context of natural kinds can enrich our understanding of Locke's empiricist philosophy.In the second chapter,the article firstly discusses Locke's theory about the meaning of natural kind terms.An effective way to understand natural kinds is to examine how natural kind terms refer to.The description theory of reference holds that natural kind terms refer to natural kinds through descriptions associated with natural kinds terms as an intermediary,while the causal theory of reference claims that natural kind terms directly refers to natural kinds without description associated with them as an intermediary.Locke considers the meaning of words or terms as corresponding to an idea in human's mind,rather than directly reflecting things in the world.Thus general terms referring to kinds correspond to abstract general idea,that is to say,kinds are just abstract ideas.Therefore,in Locke's view,natural kind terms refer to abstract ideas associated with terms,and whatever satisfies the observable properties of abstract ideas are the referents of natural kind terms.In other words,Locke can be regarded as the precursor of descriptive theory of natural kind terms.In the third chapter,we discuss whether Locke insists on natural kind essentialism.Kripke and Putnam established the orthodox view of natural kind essentialism by the causal theory of reference.This view holds that natural kinds are defined by the essence(i.e.the micro-structural characteristics of things)and things are classified on the basis of essence.Locke distinguishes between two kinds of essence,which are nominal essence and real essence.Nominal essence is an abstract idea associated with kind terms,while real essence is the internal structure of things.Locke argues that because of our ignorance of real essence,we can only classify things on the basis of nominal essence,and the continuity between species in nature indicates that real essence does not actually play any potential classificatory role.This shows that Locke rejects natural kind essentialism.In the last chapter,this article explores Locke's ontological position on whether natural kinds exist.Based on Locke's description theory of natural kind terms and his natural kind anti-essentialism,it can be seen that Locke does not recognize the existence of natural kinds in essentialist sense.In other words,Locke is an anti-realist of natural kinds.Some contemporary scholars account for natural kinds according to Homeostatic Property Cluster theory and Pluralism,and think that Locke may accept the existence of HPC kinds and natural kinds in pluralist sense.But these accounts of natural kinds are untenable.Finally,this article argues that if we understand natural kinds in virtue of Stable Property Cluster theory,it is consistent with Locke's view on natural kinds.Furthermore,it can support that Locke is a weak realist of natural kinds.