Unfortunately (or fortunately?) he falls in love with the professor’s daughter. But he is shocked to discover that the girl’s breath is poisonous. He tries to cure her and make her a normal human being. But the well-meant attempt ends in the girl’s death. The cure for poison kills her because poison was her life. Giovanni acts in love. His failure turns into Professor Rappaccini’s punishment for his evil designs. So we can say that Giovanni’s humane role brings out the moral lesson of the story. Giovanni deserves respect and pity. He is respectable because he tries to prevent the harm caused by the old professor’s love and work for science with a negative purpose. He has a positive and constructive approach to life and love. He deserves pity for the tragic end of his love affair. The irony of his fate is that his well-meant efforts to save the girl (his beloved) end in her death, whereas her father’s dangerous experiments with poison had made her life secure against poisons. Young Giovanni also deserves respect for his hard work as a student. Although he is not the central figure in the story, yet he is a lovable character for these qualities of his character.
Young Giovanni is a voice of reason in the in human atmosphere of the story. He is always worried about the danger created by the cruel old professor Rappaccini. He hates the old professor’s lust for lethal knowledge. He knows that it is actually lust for power.