“identity and Necessity” by Saul Kripke

Fernandez, Edoardo Juan B.

PHB-3

Review Essay: “Identity and Necessity” by Saul Kripke

Kripke argued on his paper “Identity and Necessity” of the possibility of contingent identity statements. He gives us a brief summary of the arguments and replies of philosophers on both sides of the issue. I believe that his summary gives us sufficient background concerning the topic at hand. After which, he proposed and concluded that identity statements, if true, are necessary. He uses the combination of the fourth line of the paradox given at the start of his paper and his use of rigid and non-rigid designators.

Kripke’s use of the paradox and “rigid and non-rigid designators”, I believe solves David Wiggins problem with line four of the paradox given at the start of the work. Kripke uses rigid designators to designate for terms or objects applicable to terms or objects on all possible worlds in which they exist. I agree with the argument and conclusion in this part of Kripke’s paper. For every object x and object y and if x=y then it is necessary that x=y. If the objects x and y here are both rigid designators then there would be no problem. In the example given by Kripke, Phosphorus and Hesperus are rigid designators and if we use line four of the paradox then phosphorus and Hesperus are necessarily one and the same that is Venus.

The use of the rigid designator and non-rigid designator of Kripke also resolves the apparent contingent identity statements like “the inventor of bifocals is the first postmaster general” if we use Kripke’s terms because they are just non-rigid designators. Kripke’s use of rigid and non-rigid designators also gives us another way of viewing or using names since in Kripkes case he proposes names as rigid designators.

Another implication of Kripke’s use of rigid and non-rigid designators is that it allows us to talk of “counter factual” situations properly. If we are to use Kripke’s rigid designators properly then we will easily be able talk of counter factual events and trans-world events like if Nixon did this and that without any issues.

Another notable part of Kripke’s paper is the distinction among a priori and a posterior as epistemic concepts, and contingency and necessity as metaphysical concepts. His argument for the possibility of of a priori contingent propositions and a posteriori necessary propositions is explained thoroughly and expounded extensively. I believe his argument concerning the possibility of a posteriori necessary judgments is correct. This also resolves the confusions with regard to apparent contingent statements.  Phosphorus and Hesperus were discovered a posteriori to be one and the same that is Venus. Using the distinction of epistemic-metaphysical concepts and the conclusion that true identity statements are necessary then we can conclude that necessarily Phosphorus is Hesperus. I believe that this may explain how and why science is able to propose and conclude necessary statements. Water is H2O or Gold has an atomic number 79 are examples of necessary but a posteriori statement.