The Pre-Socratic Philosophers are defined as the Greek thinkers who developed independent and original schools of thought from the time of Thales of Miletus (l. c. 585 BCE) to that of Socrates of Athens (470/469-399 BCE). They are known as Pre-Socratics because they pre-date Socrates.
This is a companion discussion topic for the original content at https://www.worldhistory.org/Pre-Socratic_Philosophers/.