If Sophroniscus is the father of Socrates, then Socrates is the son of Sophroniscus. If Socrates is similar to Plato, then Plato is similar to Socrates. But how many relations does Sophroniscus and Socrates being so related involve? How many does Plato and Socrates being thus related? Is there a difference between the two cases? These are questions that have featured prominently in discussions of relations in recent years, but they are by no means new. Focusing on a text by (...) the later Archbishop of Canterbury, Robert Kilwardby, this paper explores some of the replies and main arguments advanced by a number of philosophers working in the Latin west in the mid-to-late thirteenth century. (shrink)