费氏科学两原则：1）固执原则，The principle of tenacity tells us to hold onto attractive theories despite initial problems and allow them a chance to develop their potential. 2）增生原则The principle of proliferation tells us to make up new theories， propose new ideas. 费氏的原则部分地说明了为什么科学需要新颖观点的介入。但他缺乏的是抛弃和淘汰不良观点的机制。我们需要选择机制来解决实践性问题。
