As a first step of examining the „Changing Ideas of Man in European History“, as this chapter is called, we have to investigate how people in ancient Greece saw the nature of „man“.
Before Socrates, ancient Greek idea of man consisted largely of the belief in Greek mythology. People in Greece believed in a system of gods who were said to live on top of the „Olymp“, a sacred mountain. Their rule over mankind was said to have been established by a legendary fight against the titans, a different „generation“ of gods. Since their victory the Olympic gods were seen as almost omnipotent and omniscient, that means people believed in their almost absolute power on earth.
Man was considered to be at the mercy of their arbitrariness and the Olympic gods surely were a group of strangely behaving idols. Each god was held responsible for a certain kind of profession, town, action, entity and so on.
So the central aspect of the idea of man in ancient Greece was MYTH.
Socrates changed this by dinstinguishing belief (the explanation of an aspect of life by pure belief in a god; by a myth) and knowledge. Knowledge for him was a set of aspects that could be held as „true“, because they were logically explainable and did not contradict themselves. But instead of telling people what he thought, Socrates stated that he only knew that he knew nothing at all! Rather than telling people what he thought, he asked people about what THEY thought was true. By trying to answer these questions, people started to understand that logic was able to answer the central questions of life much better than the belief in myths.
Because the inhabitants of Athens started to reconsider the concept of mythology and to turn away from it towards the concept of logic, Socrates was sentenced to death by the Athenian high court and had to kill himself with a cup of hemlock. Socrates refused to accept the offer to escape the town (provided by his closest friends) because he stated that it would not be logic to break the rules a society gives itself. He also knew that in death he could spread his philosophy much better than in the rest of his life (he was 70 years old by that time).
Here is a brilliant link to an American lecture explaining the phenomenon of Socrates with an easily understandable video: