The basic notion of “union in person” is fairly straightforward. If two or more things are united in such a way that they all go to make up just one person, then the union involved is a union in person. For example, Socrates’s body and soul are united in person, and so are his soul and his left hand. By contrast, Socrates and his wife Xanthippe are not united in person, because they do not make up one person.
