This article discusses the unique practice of many philosophers in classical India to write on several philosophical and religious systems, each time adopting a sympathetic point of view for a different tradition. The article describes the development of this phenomenon in the context of interreligious debates between Buddhists, Jains, and Brahmins in the course of three distinct historical periods, transitioning from pluralism about views to pluralism about philosophical systems and culminating in the ideal of sarva-tantra-sva-tantra, a polyvocal philosopher and a polymath. Contrary to such approaches as nihilism, agnosticism, skepticism, and dogmatism, pluralism about views and systems was an attempt to justify the acceptance of several competing schools of thought. The article demonstrates that varieties of pluralism about views and systems played a role in forming and broadening philosophical alliances to defeat religious rivals, but also enhanced the scholarly reputation of erudite thinkers capable of “proving and refuting any system by will.”