Dialogs. Apology of Socrates

Platon Athenian is an ancient Greek identity philosopher, a student of Socrates, a teacher of Aristotle. It is from Plato that philosophy is formed as a system of knowledge.
“Apology of Socrates” is the first preserved text of Plato, written shortly after the trial of Socrates, and his only work, written not in the form of dialogue. So why did the Athenian state kill Socrates?
Socrates, about whom the Delphic Pythia said that there were no people wiser than him.
Socrates who went down in his history, I know that I know nothing. > Socrates, who finished his speech in the court with the words: “But it is time to go, to die, to you - to live, and what is better out of this, no one knows except God.”
All other works of Plato have The form of dialogs in which the concepts of duty and beauty, knowledge and ignorance, truth and lies, good and evil are clarified by the method of questions and answers. Socrates, as well as Pir and Fedr