2.5.1 The Cain and Abel motive
Some critics regard Amadeus as another variation of the biblical theme of Cain and Abel. Gregory Allen Robbins even calls the film version "A Cinematic Transformation of Genesis 4". In fact, there are many traces of the Cain and Abel myth as well as the underlying issues of that myth to be found in Amadeus. Those issues are the innate inequality of human beings, ambition and mediocrity, rivalry and envy between brothers, as well as the mystery of God's preference for one man over the other.
The Cain and Abel theme in Amadeus is closely connected with the view of God described in the preceding section. Salieri believes that through his hard work, his worship and chastity he has deserved God's grace. Accordingly, he takes it for granted that his wish to be the world's greatest composer will be fulfilled. When Mozart arrives on the scene, Salieri realises that his offering has been rejected and God's miraculous gift of composing eternal music bestowed upon his rival. He becomes aware that God's preference is arbitrary and does not depend on any business agreement. This sudden and bitter realisation has violent consequences: just like Cain decided to kill Abel after his gift had been rejected, Salieri now decides to destroy Mozart, the undeserving beneficiary of divine grace.
In order to achieve his goal, Salieri pretends to be Mozart's supporter and friend. He wins his trust and for a short while becomes his brother's keeper, only to ruin his plans and chances one by one. He does not kill Mozart with his bare hands like Cain, but he practically starves him by destroying any opportunity that he has to earn an income for him and his family. As opposed to his biblical precedent, he does not hope for grace anymore -- he tries to fight God as well as his chosen one. In spite of his diabolical character, he eventually becomes the loser and the victim of his own pursuit.
Another biblical reference is to Mozart as the Prodigal Son and the remorse he feels towards Leopold. Throughout all his childhood, the historical Mozart was emotionally as well as materially dependent on his father and vice versa. When he grew up, he tried to liberate himself from this impeding bond. After a violent argument, Mozart abandoned Leopold in Salzburg and married Constanze without his father's consent. This rupture has left him with a constant feeling of guilt towards Leopold. In Amadeus, Salieri learns by chance about Mozart's familial situation at a masquerade. When he sees a performance of Mozart's new opera Don Giovanni after Leopold Mozart's death, he realises that in the dreadful, accusing figure of the Commendatore, the guilt-ridden Mozart has summoned his father from the grave. He immediately recognises the power that this knowledge gives him over Mozart and he uses it to torment his victim psychologically. Masked exactly like Leopold at the masquerade, he haunts Mozart to his death.