Party systems fundamentally differ between two-party and three-party configurations.

Evidence

The typical difference in sociological constellation, thus, always remains that of two, as over against three, chief parties. A number of parties can share in different degrees in the function of the tliird, which is to mediate between two extremes. — Georg Simmel, The Sociology of Georg Simmel, 4192

Categorization

• XREF: Connects to Simmel’s triad concept that the reader is mapping onto Raskolnikov’s guilt externalization — the third party as mediator (Porfiry or Sonya).