The Aesop's fables were first compiled in the 4th century BC by Demetrius of Phalerum, but not all of them survive today. Later, many other ancient writers adapted a significant part of them, resulting in several variations of the same fable. Aesop's originality lies in the fact that he gives animals the ability to speak, offering lessons to humans, as well as the morals that are usually apt and refer to everyday life.