 Internal vs. external pluralism. From a methodological standpoint, an internal perspective is naturalistic in its reliance on the contingent plurality of scientific practice by any of its standards. This has been defended by members of the so-called Minnesota School (Kellert, Longino and Waters 2006) and Ruphy (Ruphy 2016). The alternative, which Ruphy has attributed to Dupré and Cartwright is the adoption of a metaphysical commitment external to actual scientific practice.