Period: 469 BCE to 399 BCE
SOCRATESSocrates worked on criticizing the common foundation of beliefs at his time. One of his greatest paradoxes was the weakness of will-doing wrong when you know what is right. But in the end according to Socrates, he believed that a person will only commit moral evil if he lacks moral knowledge.
Period: 428 BCE to 349 BCE
PLATOPlato tried to change the people's way of thinking of what happiness meant in their lives. His point was that we could only be happy when we are virtuous.
Period: 384 BCE to 322 BCE
ARISTOTLEHis philosophy was bounded with action conductive to man's good. He believed that virtue is something we acquire that regulate our emotions.