Who is really responsible for the death of Laura Palmer and other murder victims? Although Leland has been revealed as Laura's actual killer, the show suggests that no one in town was without some responsibility. And was Leland even guilty at all, if he was not in control of his own mind or body? Twin Peaks is about the quest for self-knowledge and the dangers of that quest, as Agent Cooper keeps learning something new about himself, as well as about the troubled townspeople. The Buddhist Cooper has to confront his own shadow side, culminating in the rite of passage at the Black Lodge, at the end of Season Two.
Twin Peaks is about madness, sanity, the borderline between them, and the necessity of some madness to make sense of sanity. The outwardly super-normal if somewhat eccentric Agent Dale Cooper is the inspired, deranged, and dedicated shaman who seeks the truth by coming to terms with the reality of unreason, partly through his dreams and partly through his existential encounters with giants, logs, outer space, and other unexpected sources. Cooper challenges official law enforcement's over-reliance on science.
Twin Peaks is about the imagination run wild, moving from metaphysics to pataphysics-the discipline invented by Alfred Jarry, which probes the assumption that anything can happen and discovers the laws governing events which constitute exceptions to all laws.