But there is a fundamental paradox in the search for such a complete unified theory.
但是在寻找这样一个完整的统一理论的过程中存在一个根本的悖论。
时间简史（原版）
We don't yet have a complete and consistent theory that combines quantum mechanics and gravity.
我们还没有一个完整而一致的理论，将量子力学和引力结合起来。
就业、利息和货币通论（下）
But as soon as we pass to the problem of what determines output and employment as a whole, we require the complete theory of a monetary economy.
但是，一旦我们谈到什么决定了整个产出和就业的问题，我们就需要完整的货币经济理论。
中医英语Oral Practice
The primitive concept of five elements later evolved into a complete and complex theory which, together with yin-yang theory, serves as a theoretical tool to understand and analyze all natural phenomena.
In mathematical logic, a theory is complete if it is a maximal consistent set of sentences, i.e., if it is consistent, and none of its proper extensions is consistent. For theories in logics which contain classical propositional logic, this is equivalent to asking that for every sentence φ in the language of the theory it contains either φ itself or its negation ¬φ.