#positivist__rationalist  someone who emphasizes observable facts and excludes metaphysical speculation about origins or ultimate causes
  supertype:  nonreligious_person  a person who does not manifest devotion to a deity
  subtype:  logical_positivist__logicalpositivist  someone who maintains that any statement that cannot be verified empirically is meaningless

No statement uses or specializes positivist; click here to add one.