The aim of this research is to clarify the base of reciprocity of ethics. Ethical theories are often divided into two groups : teleological and deontological theories. Teleological theory emphasises that morality is oriented toward bringing about a certain goal. It includes classical utilitarianism. By contrast, deontological theory claims that the wrongness of actions is intrinsic rather than the consequences it brings about. Kant is the representative theorist of deontological ethics. In Kant's normative ethics the moral law is universal. The fact that every people must follow morality's commands leads to obligatory reciprocity. Kant's categorical imperative rests upon synthetic a priori judgment. The progress of analytical philosophy has rejected the possibility of synthetic a priori knowledge. Logical positivists demonstrate a priori equals to analytic and a posteriori truths are necessarily synthetic. Quine attacks the positivist's doctrines in "Two Dogmas of Empiricism". He asserts that analytic- synthetic distinction and reductionism are two dogmas of empiricism. He advocates the holistic view of knowledge and belief. Davidson points out that Quine'sholistic theory still contains a third dogma of empiricism`scheme and content'. In the course of demonstrating against the scheme-content distinction, he uses Tarski's theory of truth andt he principle of charity. Davidson's principle of charity gives us 'radical reciprocity'. Charity is forced on us. If we do not presuppose it, we can not start communicating. No communication brings about no ethics.