The concept of logic represents the object with the proposition. The proposition has two meanings: the meaning of existence which states matters of the object, and the meaning of true value which states matters of the true value. The abstracted meaning of existence forms the synthetic proposition and nonlogical concept it contains and the abstracted meaning of true value forms the analytic proposition and logical concept it contains. Accordingly, the non-logic proposition presents the object the synthetic proposition concerns and matters of it while the logical concept reflects the character and relationship of true value. As a result, the concept of logic is diversely characteristic. In content, it represents the character and relationship of true value; in form of existence, it is the finite, common and stable of the analytic proposition; in language, it has both relatively fixed natural expressions and artificial univocal terms; in formation, it has feasible means, helping discover all parallel basic logical concepts by limited steps; in function, all concepts of logic are containers of true value, by which the true values of all analytic propositions containing the concept of logic are determined by the true values of their subpropositions. When the subpropositions they contain are identical, all analytic propositions containing different concepts of logic share all logical relationships and nurture all logical disciplines according to their differences in content.

the concept of logic; law of logic; common proposition; true value of a proposition; analytic proposition; contents of true value