Studies In Susan Haack’s Philosophy Of Logics

Susan Haack is famous as contemporary philosopher, logician and neo-pragmatist. This dissertation studied in Susan Haack’s philosophy of logics, aimed to clarify the essence of Haack’s philosophy of logics and make it show as an integral system info, discussed the scope and limits of logic, extra-systematic validity and system-relative validity, global pluralism, revisability of logic, theories of truth in turn, based on analyzing and tidying up literatures profoundly, with the mainstay of "the center problem in philosophy of logic is about the relation between informal argument and formal argument".Going with the development and maturation of classical logic, there are coming forth a lot of non-classical logics, and turn into "the age of alternative logics" which presents an omnifarious and competitive situation. Usually, scholars focused on the formal reformation, and gave little attention to the fundamental philosophy issues behind this situation. Contrarly, Haack gave high attention to the significant philosophy problems which arose by non-classical logics, with the background of "the age of alternative logics". She not only reviewed particularly the various philosophical motivations and challenges to classical logic of non-classical logics, but also reflected profoundly on the essence and status of logic, especially the function and limitation of formalization method, defended the plurality and revisability of logic from different points of view.In some sense, the main purpose of Haack’s philosophy of logics is to justify the revisability of logic, though the reviewing manner is changed. There are two different ways in Haack’s arguments:Quinian and Peircian. Other than the radical viewpoint of "variance" and unclear monism in "Deviant Logic", she distinguished expressly the metaphysical and epistemological issues of logic in "Philosophy of Logics’", turned to global pluralism and denied that deviance of system must result in substantial rival. But she always emphasized the meta-logical divarication, especially the diversity of formalization and fallibility of agent. Besides, she not only argued adequately that it is possible and necessary to revise logic, but also investigated particularly the different forms to revise logic. With a mass of case-study, she evaluated some familiar motivations which challenged potentially to classical logic. However, these so-called "challenges" are unsuccessful, and so there is no serious threat to classical logic. Despite it is possible to revise logic in principle, but it still need rather better reasons in action.Influenced by W. V. O. Quine and C. S. Peirce deeply, Haack’s philosophy of logics takes on pragmatic characters obviously:claimed thorough fallibility and revisability of logic; investigated the genesis of logic from a point of naturalism; insisted that informal argument/extra-systematic validity and formal argument/system-relative validity depend on and accord with each other dynamically; agreed with pluralism and university of logic, and against monism and extreme relativism; opposed not only the absolutization, sanctification and dogmatism of logical deferentialism, but also the debase and abuse by logical cynicism, such as nihilism, culture relativism and fashionable feminism; pulled logic from God to Human, emphasized the affinity between logic and human lives; logic is not the lawmaker beyond judgement by reason, it is just a enterprise of human; like other sciences, logic inquire is also full of bramble and complicated, progress ragged and uneven; so we should insist on innocent realism and critical common sensism, defend logic with reason.Haack’s philosophy of logics is novel and particular. She not only put forward a systematic theory about logic’s philosophy, but also exploited a lot of interesting question fields, enlarged the scope of philosophy of logic enormously. She’s clear-headed about the limitation of formalization and criticized different extremists rigorously. It is very significant to the development of modern logic healthily. However, there are some shortcomings in Haack’s philosophy of logics, for example, some core concepts and arguments need more clear and powerful accounts; the case-study is not adequate, there have some mistakes in her analysis; she is gives seldom attentions to the late literatures; besides, there is a tension between revisability of logic in principle and conservatism in action which hide in her theories.Based on Haack’s thoughts critically, I argued that:there is a basis out of logic systems, viz. the intuitive validity of informal argument. Different logics try to give different precise formulations that result in the plurality and revisability of logic in radically. In fact, classical logic have give the minimal condition of intuitive validity, namely it is cannot that premise is true but its conclusion is false. In some sense, different logics all are right, but they must satisfy the minimal condition of intuitive validity. The principles of Pragmatism, for example, simpleness and economy are very important(but not exclusive) criterions to select or evaluate certain logic system.