\begin{definition}[Definition:Pythagoreans/Quadrivium]
The '''quadrivium''' was the medieval name of the required course of study of the Pythagoreans, which had been adopted by the educational establishments in Europe.
The required bodies of knowledge were divided into '''discrete''' and '''continuous''':
Thus:
:'''Arithmetic''': study of the absolute discrete
:'''Music''': study of the relative discrete
:'''Geometry''': study of the '''stable''' continuous
:'''Astronomy''': study of the '''moving''' continuous.
\end{definition}