Full Idea
Cross-categorial sums are not unknown in philosophy. A body and the events which befall it are intimately connected, and the mysterious four-dimensional blocks might be mereological sums of the body and its life.
Gist of Idea
Sums of things in different categories are found within philosophy.
Source
Peter Simons (Parts [1987], 8.1)
Book Reference
Simons,Peter: 'Parts: a Study in Ontology' [OUP 1987], p.291
A Reaction
Simons here ventures into the territory of abstracta, which he said he wouldn't touch. Presumably his first example has 'a biography' as its whole, which is not just a philosophical notion. Why will some categories sum, and others won't?