Wang Lu

　　School of Philosophy, Zhengzhou University

　　Abstract：Metaphysics or the knowledge of knowledge itself is one of the main threads in the history of philosophy. Metaphysics is distinguished from “adding word” philosophy in that the latter is knowledge related to what the added words express. The essence of the distinction here is that metaphysics deals with what is a priori, while the study of adding word philosophies is empirical. Metaphysical inquiry always revolves around sentences, for knowledge is expressed in language, and sentences are the basic unit for the expression of knowledge.Sentences involve three aspects: at the linguistic level, the basic sentence pattern is “S is P”; at the level of sense, it is what language expresses; and at the reference level, the core concept is “truth.” Metaphysical inquiry always revolves around “being” and “truth,” and concerns the three levels above. The third level in particular reveals the conditions for the truth of a sentence, and helps explain the first two levels. We need to grasp the essence and characteristics of metaphysics and develop the study of metaphysics as a means of advancing philosophical research.

　　Keywords: knowledge, sentences, truth, a priori