Although it is often taken for granted, it is not at all clear how one can infer the validity of a general statement from a number of specific instances or infer the truth of a theory from a series of successful tests.
虽然常常被人们视为理所当然，但一个人从若干个具体的实例推断出一个一般性陈述的有效性，或者从一系列的成功试验推断出理论的真实性，这个过程其实并不清晰。