这三个阶段既是历史的统一，又是逻辑的统一。
The three stages are both history unification and logical unification.
这种写法以类相从，眉目清晰，体现了历史和逻辑的统一。
These writing methods, which are conditioned by different categories of biography, are a very clear embodiment of the unity of history and logic.
本文以系统抽象法为基本方法，坚持历史与逻辑的统一，详细占有资料。
This paper employs systematic abstract method, persisting in the unity of history and logic with possession of detailed information.
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