Abstract
A many-faceted beast, the metaphysics of relations can be approached from many angles. One could begin with the various ways in which relational states are expressed in natural language. If a more historical treatment is wanted, one could begin with Plato, Aristotle, or Leibniz. In the following, I will approach the topic by first drawing on Russell’s Principles of Mathematics
(1903) (still a natural-enough starting point), and then turn to a discussion mainly of positionalism. The closing section contains an overview of the six contributions to this Special Issue.