The definition of Heroism is: great bravery, and no other characters show such Heroism than Marlow and Gatsby. In The Heart of Darkness, Conrad uses his character Marlow to develop the theme of heroism by sending him on a quest to discover the fire and passion in his male being and ignite the flame in his heart. In The Great Gatsby, Fitzgerald uses Gatsby as his tragic hero, and though he does not fit the mold of the tragic hero, it can be argued that he inhabits the same exalted position as a tragic hero due to the rising of success and falling to ruin.
Conrad introduces Marlow as an everyday man, trying to make a living, and though his original plans were to make money, his journey turns into so much more. His expedition turns