Neopythagoreanism

Neopythagoreanism was the revival, from the first century BCE, of the number-philosophy of Pythagoras, blending mathematics, mysticism, and a longing for the divine.

Figures such as Numenius and the mathematician Nicomachus made the One and the Dyad the roots of all things, and their speculation flowed together with Middle Platonism into the great stream of Neoplatonic thought.