Greeks). Some of the hymns that Thomas wrote for the feast of Corpus Christi are still sung today, such as the Pange lingua (whose penultimate verse is the famous Tantum ergo), and Panis angelicus. Modern scholarship has confirmed that Thomas was indeed the author of these texts, a point that some had contested. In February 1265 the newly elected Pope Clement IV summoned Thomas to Rome to serve as papal theologian. This same year he was ordered by the Dominican Chapter of Agnani to teach at the studium conventuale at the Roman convent of Santa Sabina, founded some years before, in 1222. The studium at Santa Sabina now became an experiment for the Dominicans, the Order's first studium provinciale, an intermediate school between the studium conventuale and the studium generale. Prior to this time the Roman Province had offered no specialized education of any sort, no arts, no philosophy; only simple convent schools, with their basic courses in theology for resident friars, were functioning in Tuscany and the meridionale during the first several decades of the order's life. The new studium provinciale at Santa Sabina was to be a more advanced school for the province. Tolomeo da Lucca, an associate and early biographer of Thomas, tells us that at the Santa Sabina studium Thomas taught the full range of philosophical subjects, both moral and natural. While at the Santa Sabina studium provinciale Thomas began his most famous work, the Summa Theologiae, which he conceived specifically suited to beginning students: "Because a doctor of Catholic truth ought not only to teach the proficient, but to him pertains also to instruct beginners. As the Apostle says in 1 Corinthians 3:1–2, as to infants in Christ, I gave you milk to drink, not meat, our proposed intention in this work is to convey those things that pertain to the Christian religion in a way that is fitting to the instruction of beginners." While there he also wrote a variety of other works like his unfinished Compendium Theologiae and Responsio ad fr. Ioannem Vercellensem de articulis 108 sumptis ex opere Petri de Tarentasia (Reply to Brother John of Vercelli Regarding 108 Articles Drawn from the Work of Peter of Tarentaise). In his position as head of the studium, Thomas conducted a series of important disputations on the power of God, which he compiled into his De potentia. Nicholas Brunacci [1240–1322] was among Thomas's students