John of Salisbury was a 12th century Catholic philosopher during the Feudal period. He viewed political and religious authorities as having separate but related spheres - with religious authorities sovereign over spiritual matters and political authorities sovereign over temporal affairs, as outlined in the Gelasian Doctrine. According to John of Salisbury, both authorities derive their power from God, and political rulers must act in accordance with natural law and principles of equity, justice, and mercy. He also believed that while individuals have some liberty and right to tolerance, priests bestow authority on rulers and people have the qualified right to depose tyrannical rulers.

1. John of Salisbury