问题是当时没有理论解释这一点。

The problem is that the theory of the day can't explain it.

youdao

而在实际操作上，事情远没有理论简单。

In practice, things aren't so simple.

youdao

但是，没有理论能够证明二者之间的因果关系。

But there is little academically accepted evidence of a causal relationship.

youdao

A narrative theory is always talking with some satisfaction about how there's no such thing in fiction as irrelevant detail.

一个叙述性的理论通常都在讲述,小说中没有细节是完全和主题无关的这一满足感。

耶鲁公开课 - 文学理论导论课程节选

So the Hyksos theory is one that got people very excited for a while, but is really not well supported.

因此希克索斯理论能让人兴奋一阵子，但是并没有得到很好的证实。

耶鲁公开课 - 旧约导论课程节选

It's a problem, as you'll see, designed to give you some practice at dealing with some of the, dare I say, more theoretical concepts we've covered in class.

这种问题会让你在处理我们,课堂上并没有讲到的更多,理论概念这方面上有更多实践,这种问题就像算法复杂度一样。

麻省理工公开课 - 计算机科学及编程导论课程节选