what anaxagoras knew

mind (nous) is the motive force that initiated the primeval matter. Mind is completely separate from matter, the only exception to the universal criterion ‘everything in everything’. Matter under the control of Mind expands continually and indefinitely outwards from the original microdot which contained everything in the whole universe. Nous is described as ‘unlimited’, ‘self-controlling’, ‘unmixed’, ‘alone in itself and by itself’, ‘the finest’, ‘the purest’, ‘possessing complete knowledge’, ‘supreme in power’, ‘the controller of everything alive’.

http://www.philosophy.gr/presocratics/anaxagoras.htm

ah, yes, okay maybe, but when did he know it?