Eric W. Robinson has argued that Elis was a democracy by around 500 BC, on the basis of early inscriptions which suggest that the people (the "dāmos") could make and change laws. Robinson further believes that literary sources imply that Elis continued to be democratic until 365, when an oligarchic faction seems to have taken control (Xen. "Hell." 7.4.16, 26). At some point in the mid-fourth century, democracy may have been restored; at least, we hear that a particularly narrow oligarchy was replaced by a new constitution designed by Phormio of Elis, a student of Plato (Arist. "Pol." 1306a12-16; Plut. "Mor." 805d, 1126c).