For his thesis, graduate student John Marr researches the life and work of the brilliant Timothy Hassler: philosopher whose career was cut tragically short over a decade earlier. Marr encounters numerous obstacles, as other researchers turn up evidence of Hassler's personal life that is deemed simply too unpleasant and disillusioning for the rarified air of academe. On another front, Marr finds himself increasingly drawn toward more shocking, depraved sexual entanglements with the homeless men of his neighborhood, until it begins to seem that Hassler's death might hold some key to his own life as a gay man in the age of AIDS. As John Marr learns more about the enigma that was Timothy Hassler, his own increasing sexual debasement leads him to a point where his and the philosopher's lives collide violently.…Surely Samuel R. Delany's most graphic and unsettling novel, The Mad Man is a provocative look at contemporary social and sexual outsiders.