The purpose of this paper is to reilluminate the major characters of Light in August with the concept of Jacques Lacan`s four discourses. Language, on the one hand, primarily is intended to play as a key medium that attests to the identity of human and make relationships with others. On the other hand, however, it plays a role of oppressor against humane identity. As language shows such twofold characteristics, so we humans use language to establish relationships and our own identity but at the same time suffer from extreme conflicts and confusions caused by loss of identity attributable to the outright power of a huge ideologic language (discourse). William Faulkner presented, in Light in August (1932), endless chains of conflicts in relationships between a subject and others, caused by the duplexity, ambilaterality and ambiguity of a language and ontological issues of humans that suffer from these. In particular, in the novel, Faulkner showed clearly how a language binds and oppresses humans and how they are victimized by a cruel, oppressive, aery and contradictory language that affects the unconscious mind and makes them lose their identity. A language that causes humans a tragedy is a collapsed language that has oppressive bindingness. Thus the purpose of this paper is to examine the symptoms of the characters related to the mighty power of the ideological discourses with which the characters agonize within the boundary of home and society. And this study introduces Lacan`s four discourses and at the same time examines the psychological symptoms and causes of the character and the basic relationship between human subject and language in the work. Especially this study deals with the sadomasochistic hysteric discourse of Joe Christmas which are the victim`s discourses of the oppressive master`s and university`s discourse. As a whole, this work examines what message the work render to us in these days.