Natural Kinds As A Metaphysical Basis Of Inductive Inference

Induction plays an important role in people’s daily cognition and scientific cognition.Not only people’s daily life depends on reliable induction,but also the formation of scientific theory and the discovery of laws.However,the rationality of induction has been questioned since Hume.Although philosophers have been trying to defend induction in various ways,little attention has been paid to it from the perspective of natural kinds.In fact,an important motive for philosophers to pay attention to the natural kinds is to provide a metaphysical basis for induction.At least in a sense,natural kinds can explain the unity of nature,thus providing a premise for the rationality of induction.This paper first discusses the motivation of philosophers to introduce the concept of "natural kinds" and the discussion of the relationship between natural kinds and induction by early philosophers.Whewell,a philosopher of science,first introduced the concept of "class" to solve the problem of induction.The philosophers Mill and Venn also talk about induction based on the concept of "class",in which Venn especially emphasizes that the natural class is the main basis of statistical induction.However,the philosopher Quine questioned the use of the concept of natural kinds to defend induction.In Quine’s view,kind is the similarity,and its concept is very fuzzy and unreliable.As science matures,the concept of kind will disappear,so it is not suitable for defending induction.Secondly,this paper focuses on how to solve the problem of induction by the two main metaphysical theories of natural kinds,which are the traditional natural kind essentialism and Homeostatic Property Cluster theory.Natural kind essentialism holds that natural kinds are a group of things defined by the essence,and the essence is an inherent attribute of things,which is necessary for the class membership of a certain thing.Not only that,natural kind essentialism can also show that the members of natural kinds have most surface properties.It is precise because of the inherent and eternal nature of things that ensure the unity of nature,so that natural kinds terms are inductive and projective,and form the generalization and prediction about the members of the kind.In HPC theory,natural kinds are defined as a cluster caused by a potential homeostatic property mechanism.These clusters of properties are stable enough for us to induce and predict things successfully.According to HPC theory,natural kinds correspond to the objective causal structure of the world,so it can provide the ontological basis for induction.However,these two main philosophical explanations of nature have their own difficulties,which make them questioned as the metaphysical basis of induction.Finally,this paper analyzes whether natural kinds theory can provide a defense for induction.Due to the various difficulties of a unified metaphysical theory of natural kinds,with the practical turn of the philosophy of science,philosophers pay more attention to the practice of scientific classification than what the natural kinds are.At the same time,the cognitive view of natural kinds has been accepted by more and more philosophers.According to this cognitive view,natural kinds are identified by certain cognitive features that are considered evidence of the causal structure of the world.The stable property cluster(SPC)theory is a typical cognitive theory of natural kinds.SPC theory gives up the metaphysical basis of natural kinds,such as "essence" and "homeostatic property mechanism",and only focuses on the stability of property cluster,and this special stability can ensure that property cluster is helpful for induction.However,it is inevitable that stable property cluster theory only focuses on the cognitive value of natural kinds.This paper supports the theory of natural kinds as nodes in the causal network.According to the theory,natural kinds have some "core properties" and "derived properties",and there is a causal relationship between these two properties.Since the causal relationship between "core properties" and "derived properties" is stable and eternal,it can keep the nature kinds consistent,explain the unity of nature,and well defend induction.