  The first or Platonic definition, therefore, characterizes relations as the items signified by relative terms—or what we would nowadays call ‘polyadic’ or ‘many-place predicates’. The medievals regard this characterization as initially promising, and often employ it in their writings. In the end, however, they think it must be rejected—or at least modified. For according to them, not everything we are prepared to call a relation actually is a relation. In rejecting the first or Platonic definition, the medievals take themselves to be following Aristotle himself, who rejects this definition on the grounds that it allows certain substances (namely, heads and hands) to qualify as relations. As Aristotle says later in chapter 7: