On Semantically Open Philosophical Theories

Philosophy is regarded as knowledge which has the highest generality and thehighest explanation，as science which has the greatest universality，as the basis of allscience. The view is termed as “epistemological position of philosophy”. The positionis the mainstream inclination of the traditional western philosophy. The philosopherswho hold this position all devote themselves to establish philosophy as “the science ofall science”，and attempt to resolve all the theoretical questions once and for all，orprovide the certain foundation for any probable future knowledge. But this effort wasnot successful.Professor Sun Zhengyu revealed the fundamental difference of philosophy andscience profoundly who using the superficial contradiction of Engel’s thesis on “thebasic question of philosophy” and “premises of theoretical thought” as the startingpoint. He made a point that human’s thinking should be divided into two dimensions,“constructing thought” and “reflecting thought itself”. And then he criticized“epistemological position of philosophy” based on this view systematically.Polish–American logician Tarski established “theory of language hierarchy” thatformal language was divided into “object language” and “metalanguage”，and defined“semantically closed language” and “semantically open language” under the pair ofconcepts. He also thought just could construct the “materially adequate and formallycorrect” definition of the concept of “truth”.To combine professor Sun’s theory and Tarski’s theory，that is to say “theory oflanguage hierarchy” is extended to the general theoretical issues，and then just canrefute “epistemological position of philosophy” on the semantics. Any theory in relationship of “discussing and being discussed” can be divided into “object theory”and “metatheory”. In general, if theory B is an object to theory A, then A is the“metatheory” for B, B is the “object theory” for A. From a functional perspective,“metatheory” is for discussing “object theory”；From a structure perspective,“metatheory” contains all propositions、the names of these propositions、predicates forpredicating these names and necessary logical connectives of “object theory”. Atheory, if “object theory” and “metatheory” separate from each other, is “semanticallyopen theory”; otherwise is “semantically closed theory”. The so-called “separation” isthe separation of the functions of “object theory” and “metatheory”，that is to say, thistheory just discusses its theoretical object without discussing itself.The philosophers who hold the “epistemological position of philosophy” believethat there is a theory as the “metatheory” of all theories，and the theory can be termed“metascience”. On the semantics,“metascience” must be a semantically closed theoryor a semantically open theory. If it is semantically closed, then we can prove that itcontains one unprovable true proposition at least，and explain it does not have thefunction to give proofs to every true proposition in it. The proofs of these propositionsshould carry on in the hierarchy higher theories；If it is semantically open，then it isnot its own metatheory, even nor is it metatheory of all theories. In any case, theconcept of “metascience” is semantically contradictory.Philosophy, as a theory, just can be a semantically open theoretical series and carryon “criticism of theoretical thought premises” endlessly.