Full Idea
If events are classes, as I propose, then they have a mereology in the way that all classes do: the parts of a class are its subclasses.
Gist of Idea
Events are classes, and so there is a mereology of their parts
Source
David Lewis (Events [1986], V)
Book Reference
Lewis,David: 'Philosophical Papers Vol.2' [OUP 1986], p.258
A Reaction
Lewis says events are properties, which he regards as classes. It is not clear that events are strictly mereological. Could one happening be two events? Is WWII a simple sum of its parts? [see p.260]