"۔۔۔the subject of philosophy, as it is often conceived—a rigorous and systematic examination of ethical, political, metaphysical, and epistemological issues, armed with a distinctive method—can be called his invention" (Richard Kraut (11 ستمبر 2013)۔ مدیر: Edward N. Zalta۔ "Plato"۔ The Stanford Encyclopedia of Philosophy۔ Stanford University۔ اخذ شدہ بتاریخ 3 اپریل 2014تحقق من التاريخ في: |access-date=, |date= (معاونت))
"Though influenced primarily by Socrates, to the extent that Socrates is usually the main character in many of Plato's writings, he was also influenced by Heraclitus, Parmenides, and the Pythagoreans" (http://www.iep.utm.edu/plato/)۔
