This paper is divided into three parts.The first surveys Wittgenstein’s anti?essentialistic program viz.theories of “family resemblance”and “language?games”comprehensively.The second points out that Wittgenstein’s program is false according to the principles of “Membership Rigidity”and of “Crossworld Extensionality”in modal set theory based on essentialism.The third is the opinions I wish to discuss with Zhang Zhilin’s anti?essentialistic program based on Wittgenstein’s theories of “family resemblance”and “language?games”.
This paper is divided into three parts. Firstly, it summarizes four theories of the proper name and the description. Secondly, it investigates Kripke’s theory of designators, and makes supplementary demonstration by means of possible worlds semantics. Thirdly, it replies to Quines’s censures about the principle of substitution of identity and the rule of existential generalization according to Kripke’s theory of designator.
