一 孙绍振先生对波普尔的“可证伪性”情有独钟。他总是不满足于证明“一切的天鹅都是白的”，信奉“一切的天鹅并不一定都是白的”这样的证伪命题可能更有价值。这位至今仍然能够背诵元素周期表的文学教授从青少年时期便受到自然科学方法的熏陶，在北大读书期间他对朱德熙、王 One Mr. Sun Shaozhen had a soft spot for Popper’s “falsifiability.” He is always not satisfied with proving that “all the swans are white,” and that falsifying propositions that “all swans are not necessarily white” may be more valuable. The literary professor, who still can memorize the periodic table, has been influenced by the methods of natural science since he was a teenager. During his reading at Peking University,