Tutorial #10. Kripke on Names. Nuts and Bolts

Bits of Terminology

Possible Worlds: Ways things could have been.
The actual world: the way things actually are.
Possible worlds, in philosophy, are used to explain modal notions like logical possibility, necessity and contingency.

--> Necessary & Contingent
- A state of affairs is logically possible if it’s true at some possible world.
- A proposition is necessarily true if it’s true at all possible worlds.
- A proposition is contingently true if it’s true at the actual world (or the world we’re considering) but false at some other possible world.


--> A priori & A posteriori
- A priori: knowable "before" experience. E.g. "All bachelors are unmarried."
- A posteriori: can only be known "after" experience. E.g. "Miriam is 10 ft. tall"

NOTE
A priority and a posteriority are epistemic notions.
Necessity and contingency are metaphysical notions.


+ Kripke On A Priori\A Posteriori & Necessity\Contingency:

Some a priori propositions are contingent!
Example: The standard meter rod in Paris is one meter long.

Some a posteriori propositions are necessary!
Example: Water is H2O.