End of Term Quiz
Answer any TWO of the questions below by writing essays of between 500 and 750 words on each.
- What does it mean to say that an expression is a rigid designator? What is Kripke’s argument that proper names are rigid designators, but that descriptions associated with them by speakers aren’t? What are his strongest arguments against the view that the linguistic rule for determining referent of a proper name is that the referent of a name, as used by a speaker, is whatever object, if any, is uniquely denoted by the descriptions the speaker associates with the name?
- First give Kripke’s best argument for the existence of necessary truths that can only be known aposteriori. Then consider the following objection To the necessary aposteriori truths.
“You have admitted that heat might have turned out not to have been molecular motion, and that gold might have turned out not to have been the element with the atomic number 79. For that matter, you also have acknowledged that …this table might have turned out to be made from ice from water from the Thames. I gather that Hesperus might have turned out not to be Phosphorus. What then can you mean when you say that such eventualities are impossible? If Hesperus might have turned out not to be Phosphorus, then Hesperus might not have been Phosphorus. And similarly for the other cases: if the world could have turned out otherwise, it could have been otherwise. (140-1)
The objection covers all cases of the necessary aposteriori. Since p is aposteriori, its falsity must be conceivable, and so, it seems, knowledge of p must require empirical evidence ruling out possibilities in which p is false. Without such evidence, p could turn out false. But, the objector argues, if p is necessary, there are no such possibilities to be ruled out, since no matter what possible state the world is in, it is one in which p is true. Thus, if p is necessary, we don’t need empirical evidence to know p after all, and if p is aposteriori, it isn’t necessary. Either way, the necessary aposteriori is an illusion.
What is Kripke’s best response to this objection?
- Consider the following examples: Lightning is electricity, and Light is a stream of photons. In lecture 3 Naming and Necessity, Kripke says that these are examples of the necessary aposteriori. He even calls them “theoretical identification” statements, which might seem to suggest that they are statements of the form A = B. But there is reason to believe they are not. Explain why and provide an alternative logical form for these statements – which is, arguably, also the form of Ice is H2O. Then, assuming they are true, explain why Kripke would claim they are both necessary and knowable only aposteriori.
- How should the Kripkean answer the questions: Can one know that Hesperus is Hesperus without knowing that Hesperus is Phosphorus? Can one know apriori that Hesperus is Phosphorus? Is the proposition that Hesperus is Phosphorus an example of the necessary aposteriori? Explain why the answers you suggest are the best ones the Kripkean can give, including what, if anything makes them persuasive.
