Abbot of the Cistercian monastery at Clairvaux, Bernard became a force for the reform of monasticism and of the entire church. He advocated an austere asceticism for monks and a rigorous orthodoxy in faith and practice for the church. In theology Bernard was strongly Augustinian. A profound mysticism appears in his meditations on the love of God and the humanity of Christ. Both of these themes are apparent in the hymn attributed to him: "O Sacred Head, Now Wounded." In practice Bernard was an advocate of ecclesiastical reform, an aggressive ecclesiastical diplomat, an advocate of papal prerogative, and a preacher of the crusades.