Causal Theories of Reference

Causal theories say that Christopher Columbus got his name at his baptism, when his parents said 'This is Christopher Columbus' (or something similar). They told the name to other people, including Christopher himself, and this causal chain transmits the reference. Even if everything you believe about him is false, you still refer to the same person if the causal chain behind your use of the name stretches back to him.

Names also refer to the same things in all possible worlds -- they are rigid designators. This means that if two names refer to the same thing in this world, it is not possible for them to refer to different things in other worlds. Similarly, if they refer to different things in this world, they cannot refer to the same thing in other worlds.

Problems

Multiple Chains

Suppose you have heard of several John Smiths, but don't actually know how many of them are 'the same person'. When you refer to 'John Smith', to which one do you refer?

Homer

The causal chain for our use of the name 'Homer' might not go back to the author of the Iliad and Odyssey. If it does not, then those poems were not written by Homer. However, the author might still have been called 'Homer'. In which case, the Iliad and Odyssey were not written by Homer, but by another gentleman of the same name. But this seems absurd: if there was a person called Homer who wrote both poems, then surely we refer to him when we use the name.

Transworld Identity

What counts as being the same person or thing in a different possible world? Is there a possible world in which I am a woman? A tree? A galaxy? What about worlds where my mother gave birth to identical twins -- which one is me?

Literature

Kripke 1980 is the main source for this.