在《费曼物理学讲义》里
第一章第一节第五段：
The principle of science, the definition, almost, is the following: The test of all knoledge is experiment. Experiment is the sole judge of scientific "truth".
第三章第一节第一段：
Mathematics is not a science from our point of view, in the sense that it is not a natural science. The test of its vidality is not experiment.
最后补充说明一段：
We must, incidentally, make it clear from the beginning that if a thing is not a science, it is not necessarily bad. For example, love is not a science. So, if something is said not to be a science, it does not mean that there is something wrong with it; it just means that it is not a science. 同样出自费曼物理学奖以第三章第一节第一段。
这段话可以借用过来说中医：尽管中医不是科学，但这并不意味着它有什么不好。