In 388, Augustine returned to his native Africa and settled in his home town of Thagaste to practice an experiment in ascetic retirement. The Thagaste community he developed, despite not being called a monastery, was in practice the first monastic community in Latin Africa. ‘A philosophical society’ looks to this period to analyse how Augustine's thoughts changed during this time. It was a fruitful time for his writing. The gradual change from teaching the liberal arts to studious engagement with theology was marked by his six books On Music. The first five books were concerned with metre and rhythm, but the sixth was a restatement of Plato's belief that mathematical principles underlie everything in the universe.