The Divine Comedy is an Italian narrative poem by Dante Alighieri, begun c. 1308 and completed around 1321, shortly before the author's death. It is widely considered the pre-eminent work in Italian literature and one of the greatest works of world literature. The poem's imaginative vision of the afterlife is representative of the medieval worldview as it existed in the Western Church by the 14th century. It helped establish the Tuscan language, in which it is written, as the standardized Italian language. It is divided into three parts: Inferno, Purgatorio, and Paradiso. The poem discusses "the state of the soul after death and presents an image of divine justice meted out as due punishment or reward", and describes Dante's travels through Hell, Purgatory, and Heaven. Allegorically, the poem represents the soul's journey towards God, beginning with the recognition and rejection of sin (Inferno), followed by the penitent Christian life (Purgatorio), which is then followed by the soul's ascent to God (Paradiso). Dante draws on medieval Catholic theology and philosophy, especially Thomistic philosophy derived from the Summa Theologica of Thomas Aquinas. Consequently, the Divine Comedy has been called "the Summa in verse".