Pitagora e l'aritmo-geometria

The idea that reality is a number, as well as the conception of mathematics as theoretical disciplines are traditionally attributed to Pythagoras. In fact, it is difficult to determine what goes back to his teaching and what should belong to the later developments. Certainly the interest in the number and its properties characterizes already the most ancient nucleus of the school. At this stage, the arithmetic and geometry are closely related to one another: only the discovery of the irrational leads to distinguish the study of discrete numeric from that of the continuous space.