The Realm of Numbers

Dao [Zero] gives birth to One
One gives birth to Two
Two gives birth to Three
Three gives birth to the Myriad Things
-- Dao De Jing (the beginning of chapter 42)

Pythagoreans did not differentiate the realm of numbers from the physical world. To them, visible reality actually consisted of numbers instead of just reflecting their ideas.

The theory of Digital Physics regards discrete information as the ultimate "substance" of the universe. Since information can be presented as numbers, the basic idea of Digital Physics is very close to that of Pythagorean cosmology.

The type of philosophy which believes in the independent existence of numbers is called "mathematical realism".