二律背反是康德的哲学概念。意指对同一个对象或问题所形成的两种理论或学说虽然各自成立但却相互矛盾的现象，又译作二律背驰，相互冲突或自相矛盾。

如果关于同一对象有两种功效相同的科学理论，科学家是兼收并蓄，还是取此舍彼?一般，他们总是选取那个形式更加简洁明了的。这项冥冥中支配着科学家的思维产品标准古怪地称为“奥坎剃刀”。

“奥坎剃刀”的提出者是英国中世纪经院哲学家、方济谷教士奥坎(Occam,或Ockham，约1285－1349)。他写的是拉丁语句，中文可以翻译为“理论忌繁复”。后来，奥地利出了一位理论物理学家马赫，他对科学里的哲学问题喜欢发表意见，也颇有见地，他把“奥坎剃刀” 总结成下面的明晰话语：　　全部科学的目的就是对事实进行想象和模拟，并更新我们的经验，或者把它简化。要选择那些比经验本身要来得轻巧的加以抽象，用它来代表许多其他事物。这一“节约原则”贯彻在科学精髓之中，其实对我们日常的思考也适用。而且，我们愈认识节约的必要，神秘主义就愈无法藏身。

所以，“奥坎剃刀”还真左右着科学的审美观，其实也就是评判科学的一项标准呢!

Xinyu Li, China, SecondaryTeacher of Information Technology.mingxiao's blogFocusing on media and educational technology.Theme: web2.0 tools, media and software applications, social learning

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