On Ruth Chang's Value-relationship Thought

The idea of value-relationship works as the starting point and the basis in Ruth Chang's philosophical thought.It mainly includes two parts: comparability thought and parity theory.Ruth Chang started from the thinking of the incommensurability so-called by predecessors,and explored three kinds of incomparability of values according to the theory of Positive Value Relationship,Covering Value and The Structure of Values.Combining with the The Small Improvement Argument and The Pareto Argument,Ruth Chang rebutted the Trichotomy Thesis according to which if two items are comparable,one could only be better than the other or worse than the other or they two are equally good and proved the existence of the fourth value relationship,parity.The existence of parity not only expands the logical space of value-relationship,but also confirms the correctness of her definition of comparability.Ruth Chang transformed parts of Richardson's and Raz's thoughts on commensurability into her own Covering Value Requirement,and removed the substantive judgment of Griffin et al.She also took advantage of Bloom and Parfit's approach to logical analysis of valuerelationship.Ruth Chang's parity theory is similar with Raz's "incommensurability",Parfit's "rough comparability",Griffin's "vague ordering",and Bloom's "vagueness" in some way but still different essentially.Ruth Chang's value-relationship theory has developed the traditional value-relationship theory a lot,but problems worth further discussion arise at the same time: the metaphysical description of the parity is far from clear;the Pareto argument contains implausible presupposition;what be interval-represented are evaluative differences rather than values;there may be more relationships under the interval model.These discussions ultimately lead to a new model that uses vectors rather than numbers(or number sets),through which various value-relationships may be easily and efficiently understood.