Willy values success, public perception, material gain, and respect above all.He shows us repeatedly throughout the play his affection towards Biff's character by portraying his moral code which enables the reader to relate and respect Biff.We can see Biff really grow as a character throughout the play, he develops an admirable moral outlook on life.Willy's deep-seated need to achieve his life values governs him and takes over his mind.His failure to achieve the things he holds most valuable destroys his self worth and highlights his insecurities.Towards the end we get the sense that Biff is starting to value himself more as he becomes more sure of who he is. He's able to show his emotions to Willy and this provides the reader with a better understanding of who he really is. Miller values the truth, family, love and happiness.He values a man's word and is heartbroken by his father's infidelity.