Brecht narrates the story of the great scientist of Renaissance with the ingenious personality and the passions for inventions. Central motive of the play is the supreme duty of the scientist for his fellow-beings and by extension, the duty of every man for the others. The story develops through a succession of autobiographical scenes. The theatrical hero Galileo is an exuberant figure of Renaissance, ahead of his time, with only purpose in his life the quest of the truth. However, facing the threat of the Pope and the Inquisition he loses his self -control and denounces all his beliefs. The end is hopeful as Galileo concludes and then secretly protects his last and most important research.