“推理”的双重语义与逻辑学层级——哈曼与菲尔德之争辨析

The Double Meanings of “Reasoning” and the Hierarchy of Logic:An Analysis of the Debates Between Harman and Field

随着"逻辑的认知转向"兴起,实际推理过程研究被越来越多的学者视为逻辑学的一部分。这似乎违背了弗雷格的"反心理主义",因而引起学界的争议。哈曼从"推理"的双重语义出发,否定逻辑与实际推理过程之间存在无例外的关联原则,论证实际推理过程研究应排除在逻辑学之外;菲尔德则肯定这种原则的存在,论证逻辑是规范性学科。引入层级分明的"大逻辑观"视角可知,这种关联原则存在与否,应属于"应用逻辑"层面的问题,因而无法决定逻辑本身的学科范围。在一定意义上,实际推理过程可作为逻辑研究对象。

With the rise of the 'cognitive turn of logic',the study of practical reasoning has been regarded as a part of logic by more and more scholars. This seems to go against the anti-psychologism of G. Frege,thus causing academic controversies. From the double meanings of 'reasoning',G. Harman argues that there is no unexceptionable principle of connection between logic and practical reasoning,and that the study of practical reasoning shall be excluded from logic. On the contrary,H. Field affirms the existence of such principle and argues that logic is a normative subject. From the perspective of a clearly hierarchal 'view of logic in a broad sense',it can be seen that the existence or absence of such principle of connection shall belong to the level of applied logic,so that the scope of logic itself cannot be determined. In a certain sense,the practical reasoning can be one of the objects of logic study.