Greece

Protagoras (approximately 490 or 480 BC to 420 or 410 BC) In the 5th century BC, the Greek city-state democratic politics was highly developed. Protagoras He is the main representative of the Sophists. He advocated that "man is the measure of all things." Protagoras was born between 490 BC and 480 BC, and lived about 70 years old. He was born in the city of Abdera. He came to Athens, the center of the Greek slave-owning democracy at that time, many times. He became close friends with the democratic politician Pericles. He once formulated a code for the Athenian colony of Turi in southern Italy. He traveled around various places throughout his life, taking on apprentices and imparting knowledge of rhetoric and debate. He was the most respected "wise man" at that time.

He put forward a famous proposition: "Man is the measure of all things." He believed that the existence of things is relative to human feelings. Things are how people feel. The existence, nature and form of all things are relative and completely determined by human subjective feelings. From this, he concluded that "knowledge is feeling" and advocated that knowledge can be obtained with the help of feeling. Based on this point of view, he raised doubts about traditional religious theology: "As for gods, I neither know whether they exist nor what they are like." This emphasis on human beings as the subject of understanding objective things denies the role of supernatural forces such as God or fate in life and establishes human dignity. However, this kind of thinking ignores the role of law and is not conducive to social stability. Later Socrates proposed that "thinking people are the measure of all things."