Logical Pluralism: Correct Logics and the Problem of Disagreement

逻辑多元化是指至少有两个相互对立但同样正确的逻辑系统。它直接反对逻辑一元论，根据逻辑一元论，只有一个正确的逻辑，并反对逻辑虚无主义--认为根本没有正确的逻辑。一般说来，逻辑多元化是由存在多个不同的逻辑系统这一事实推动的。更具体的版本产生于对逻辑的正确性和逻辑系统如何彼此不一致的不同观点。该研究项目涉及到这两个方面。它的目的是调查是否可以形成一种合理而稳定的逻辑多元化版本。该项目的第一个目标是为逻辑的“正确性”找到可行的标准。一种广泛的观点是，这些标准涉及到将逻辑应用于特定的主题领域。然而，对于应该考虑哪些主题领域，人们的共识较少。除了直觉上有效的论点或自然语言的论点，人们还可以求助于推理的规范或逻辑柏拉图主义等形而上学的强有力的假设。逻辑多元化的合理性至少在一定程度上取决于它与不同提议的兼容性。这样做的目的是澄清这个问题。不一致的问题将结合逻辑哲学中的一个经典立场来讨论。W.V.O.奎因的“意义-变异命题”主张，逻辑的改变就是主题的改变。更具体地说，观点认为逻辑常量的含义取决于包含这些常量的系统的逻辑原则。这篇论文与多元论直接相关：如果常量的含义随着不同的逻辑系统而变化，那么系统之间的不一致并不明显。一个有争议的陈述，比如，“p或非-p”，可能只是意味着不同的事情。在研究项目中，我将把对意义变异命题的讨论与当前语言哲学中关于分歧的争论联系起来。可以预料的是，这将导致对讨论逻辑多元化有价值的见解。逻辑多元论的两个特征--不同逻辑系统的正确性和不一致性--都需要进一步澄清。拟议的研究项目的目标是为这项任务作出贡献。

Logical pluralism is the thesis that there are at least two opposing, but equally correct, logical systems. It is directly opposed to logical monism, according to which there is only one correct logic, and to Logical Nihilism-the view that there is no correct logic at all. In general, logical pluralism is motivated by the fact that there is a plurality of different logical systems. More specific versions result from different views on the correctness of a logic and on how logical systems can disagree with one another. The research project is concerned with both aspects. Its aim is to investigate whether a plausible and stable version of logical pluralism can be formulated. The first goal of the project is to find workable criteria for the "correctness" of logic. A widespread view is that those criteria concern the application of a logic to a specific subject area. There is less agreement, however, on what kinds of subject areas are to be considered. Apart from intuitively valid arguments or natural language arguments, one might resort to norms of reasoning or to metaphysically strong assumptions like logical Platonism. The plausibility of logical pluralism at least partly depends on its compatibility with different proposals. The aim is to clarify this issue. The problem of disagreement will be discussed in connection with a classical position in the philosophy of logic. W.V.O. Quine's "meaning-variance thesis" claims that a change of logic is a change of subject. More specifically, the view is that the meaning of the logical constants depends on the logical principles of the system containing those constants. The thesis is immediately relevant for pluralism: If the meaning of the constants varies with different logical systems, then it is not obvious that the systems disagree. A controversial statement like, for instance, "p or not-p" could simply mean different things. In the research project, I will connect the discussion of the meaning variance thesis to the current debate on disagreement in the philosophy of language. It is to be expected that this will lead to insights valuable to the discussion of logical pluralism. Both characteristic features of logical pluralism-the correctness and the disagreement of different logical systems-are in need of further clarification. It is the goal of the proposed research project to contribute to that task.