Pythagoras was a Greek philosopher from the island of Samos who lived during the 6th century BCE. After extensive travels, he settled in the city of Croton in southern Italy, where he founded a unique religious and philosophical community. This secretive society followed strict rules and dedicated itself to the study of mathematics, music, and astronomy. The community became involved in local politics, which eventually led to a violent uprising. The exact circumstances of Pythagoras's death are uncertain, but it is generally believed to have occurred around 500 BCE.

Pythagoras himself left no writings. All his teachings were passed down orally within his school and were later recorded by his followers and other ancient authors. Therefore, no works directly authored by him survive. The ideas attributed to him come from later Pythagorean philosophers and accounts by figures like Plato and Aristotle.

His historical importance is profound. Pythagoras is considered a seminal figure who established a way of life where intellectual and spiritual purification were linked. According to modern scholars, his most significant legacy is the promotion of the idea that numbers and mathematical relationships are the fundamental basis of reality. Concepts developed within his school, such as the harmony of the spheres and the transmigration of souls, deeply influenced later Greek philosophy, especially Plato. While the famous geometric theorem bears his name, there is no evidence he discovered it; his true significance lies in founding a tradition that shaped Western philosophical and scientific thought.