Davidson proposes a causal law for singular event causation. Here is one example of a backward-looking part of such a law (changed slightly for clarity and to avoid copyright infringement):
(e)(u)((Ge & (t(e) = u + ε)) -> (∃!q)(Fq & (t(q) = n) & C(q,e)))
Notes:
- e, q are event variables
- G, F are event predicate variables
- u is a time
- let me know if anything else is unclear
Problem:
What is "(∃!q)"? I wasn't able to find this notation on google, nor in an article on Davidson's theory of causation (e.g. Wirderker 1985).
My gut instinct is that this has to be simply (∃q). Then much of the formalism makes sense.
Yet obviously "!" is often used for negation. But in a law-denoting conditional, why would a universally quantified statement over events lead to the negation of a statement that an event exists that caused it?
Edit: answered.
