Thales of Miletus & Pythagoras of Samos
http://dir.yahoo.com/Arts/Humanities/Philosophy/Philosophers/Thales_of_Miletus__c_634_c_546_BCE_/
http://www.thebigview.com/greeks/index.html
http://www.crystalinks.com/pythagoras.html
http://plato.stanford.edu/entries/pythagoras/
Plato’s homework problem