Full Idea
The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature', because nature is a harmony of three concords (4th,5th and octave), and these ratios (4:3, 3:2, and 2:1) are found in the tektraktys.
Gist of Idea
The tektraktys (1+2+3+4=10) is the 'fount of ever-flowing nature'
Source
Sextus Empiricus (Against the Professors (six books) [c.180], 7.95)
Book Reference
'The First Philosophers', ed/tr. Waterfield,Robin [OUP 2000], p.102