| The main issue of this paper focuses on Ross’ s Infinite Regress Argument against Kant’s theory of duty of “to act from duty” in the book “The Right and Good”.First,it elaborates and reconstructs Ross’ s Infinite Regress Argument,then examines the response of Shillinglaw and others to Ross’ s argument from three levels,and finally admits that Ross’ s argument is flawed,that it fails to effectively accuse Kant’s theory of duty of falling into infinite regress.However,further,beyond the theoretical confrontation between Kant and Ross,Ross’ s argument reveals that the theory of duty itself faces the problem of infinite regress,and this more general problem is the core of this paper.We try to use the tool of The Deflationary Theory of Truth to solve the problem of infinite regress.Next,it examines sorts of versions of The Deflationary Theory of Truth and defines the core view of which,that the predicate “true” can be semantically deflated because it does not add any new things to the content of the whole statement,and it only plays a formal role,which inspires the extension of deflation,that is,the deflation of the predicate to the subject in the analysis proposition.Finally,we try to use the deflation of the predicate to the subject in the analysis proposition to deflate the infinite regress of duty on the semantic level.It mainly examines the feasibility of application to duty.By analogy,we can apply this kind of deflation to duty.What’s more,we need to stand on the position of expressivism and then clarify that the duty in this paper is the duty in expressivism.Above,this paper uses the core view of The Deflationary Theory of Truth to solve the problem of the infinite regress of duty.It believes that “duty” entails “to act from duty” semantically,and draws the conclusion that duty is deflationary and this conclusion is considered to be a semantic fundamental of motivational internalism. |