 There are a number of reasons we should be wary of characterising relations in such quasi-mathematical terms. First, sequences presuppose order, the difference between a thing’s coming first and thing’s coming second, so cannot be used to explain order without our going around in a tight circle. Second, it’s problematic to try to explain a relation between two things in terms of another thing, a sequence, which is those two things put together in an order (MacBride 2005: 590–2). If a sequence \(s\) (\(=\langle x, y \rangle\)) is conceived as a “one” such that a relation \(R\) is really only a monadic feature of it, \(R(s)\), then it’s mysterious what \(R\)’s holding of \(s\) has to do with \(x\) and \(y\) being arranged one way rather than another with respect to \(R\). If you don’t see the mystery straightaway, reflect that \(s\) may have a monadic feature \(F\), which is, so to speak, only to do with \(s\) itself rather than its members. But if \(R\) and \(F\) are conceived alike, as monadic features of \(s\), isn’t it mysterious that the possession by \(s\) of \(R\) has consequences for \(x\) and \(y\) whereas \(F\) doesn’t? If, alternatively, a sequence is conceived as a “many”, just \(x\) and \(y\), such that \(R\) applies to them directly, then it’s unclear what the appeal to sequences has achieved.