Theory means to abstract and summarize objective realities or phenomena, whose basic aspect is concept, through it to arrange and study knowledge properly.

理论是对客观现实（现象）的抽象和概括，理论最基本的方面是概念，通过它对知识进行有条理的编排和研究。

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The truth of any knowledge or theory is determined not by subjective feelings, but by objective results in social practice.

判定认识或理论之是否真理，不是依主观上觉得如何而定，而是依客观上社会实践的结果如何而定。

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