The pseudonymous Thirteenth Letter of Plato claims that Speusippus married his niece ( his mother 's granddaughter ) .
Speusippus was a native of Athens , and the son of Eurymedon and Potone , a sister of Plato .
The pseudonymous Thirteenth Letter of Plato claims that son married Speusippus ' niece ( his mother 's granddaughter ) .
Speusippus was a native of Athens , and the son of Eurymedon and Potone , a sister of Plato .