When seeking to understand the nature of the investment treaty system, participants routinely draw analogies from and with public international law, international commercial arbitration, public law, trade law, and human rights law. However, these analogies frequently point to distinct (and sometimes clashing) conclusions as a result of differences in their underlying paradigms. This article examines what each paradigm reveals and obscures about the investment treaty system and how the backgrounds and interests of different actors inform their choice of analogies.