普特南量子逻辑思想的演变

The Conceptual Evolution of Putnam’s Thought on Quantum Logic

普特南曾提出“逻辑是经验的”这一惊世骇俗的论题。他主张,正如广义相对论揭示出非欧几何才是真正描述现实世界的几何学一样,量子力学也意味着量子逻辑才是隐藏在经典逻辑背后的“真逻辑”。然而鲜为人知的是,普特南口中的“量子逻辑”这一概念曾经历过重大的转变。但是概念的修正并没有帮助普特南成功地论证量子力学命题真值的实在性,并且他最后也不得不承认非欧几何与量子逻辑的类比是不妥当的。应该说,普特南的工作确实说明量子逻辑可以提供同样好的量子力学解释,不逊色于保留经典逻辑的解释;但量子逻辑并不是唯一的“真逻辑”,无论是否局限在量子逻辑的范围内,围绕着量子力学解释的逻辑系统都是支持着逻辑多元主义的。

“Logic is empirical”is the astonishing point that Putnam raises.He argues that according to quantum mechanics,quantum logic is the true logic hiding behind classical logic,exactly in the same way as non-Euclidean geometry,revealed by general relativity,is the true geometry describing the real world.But what is less known is that Putnam’s concept of“quantum logic”has changed significantly in his later years.The change of this concept,however,does not help Putnam argue successfully for the reality of the truth values of quantum mechanical propositions,and he has to admit at last that the analogy between non-Euclidean geometry and quantum logic is not appropriate.We should admit that Putnam’s work proves that quantum logical interpretations of quantum mechanics are as good as other interpretations that preserve classical logic.But quantum logics are anything but the unique,true logic;the logical systems concerning interpretations of quantum mechanics are supporting logical pluralism,whether we confine ourselves to quantum logical systems or not.